ALBERT

Notes: Live cells of E. coli O157:H7 were labeled by 4′,6-diamidino-2-phenylindole (DAPI) in buffers of different pH. The extent of labeling was relatively insensitive to pH in the range of 6.5 to 9.5. The fluorescence intensity of ± 104 DAPI-labeled bacteria per mL in optical cuvettes could be detected by a luminescence spectrometer. With a fluorescence microplate reader attachment, less than 103 of labeled bacteria could be measured. DAPI-labeling inhibited the growth and respiratory activities of the bacteria. The addition of 0.5 to 6 mM concentrations of ATP induced a substantial increase in the fluorescence of labeled bacteria. Maximal enhancement by ATP was observed from bacteria still maintaining low levels of physiological activities. The enhancement favored more alkaline media with pH greater than 9. A replacement of ATP with ADP or AMP diminished the extent of enhancement. Other triphosphate nucleotides did not enhance fluorescence of DAPI-labeled bacteria. Comparable ATP enhancements were also observed with Pseudomonas alcaligenes and Shewanella putrefaciens. Solubilization/destruction of cell membranes of labeled bacteria by detergents essentially eliminated the ATP enhancement. Absorption and fluorescence spectroscopic measurements indicated that ATP could interact with free and bound DAPI. These results suggest that observed ATP enhancement in fluorescence intensity of DAPI labels in intact cells may be applied to increase the sensitivity of microorganism detection.

Notes: Fungal biota, with special reference to the genus Penicillium, was studied in 52 samples of commercial cheeses (10 fresh, 17 semiripened and 25 ripened) made from different types of milk (cow, ewe, goat and mixed) produced in southern Spain. In 41 of the total of cheeses analyzed (79%) molds were isolated. Penicillium was identified in 63% of the samples, Mucor spp. in 27%, Geotrichum candidum in 17% and Cladosporium herbarum in 10%; eleven other fungal genera were detected ranging from 2 to 4%. Thirty-five species of Penicillium were analyzed with the following distribution: 7 in fresh cheese, 16 in semiripened cheese and 30 in ripened cheese. The incidence of Penicillium spp. was also greater in the cheeses with a higher degree of ripeness, i.e. 20% in fresh cheese, 71% in the semiripened and 76% in the ripened cheese.

Notes: Challenge studies were carried out on raw, cooked, and sterilized surimi nuggets, inoculated with 104spores/g of C. botulinum type E spores. All products were packaged in air and air with an Ageless SS oxygen absorbent and stored at 4, 12 and 25C. Toxin was not detected in any raw product throughout storage (28 days). The absence of toxigenesis was attributed to the low pH (4.1–4.3) due mainly to the growth of lactic acid bacteria (107CFU/g). Toxin was also not detected in any cooked product after 28 days. Product pH did not decrease as previously (due to the absence of LAB), but counts of C. botulinum still decreased throughout storage. In sterile nuggets, C. botulinum counts increased to 106 cfu/g at both 12 and 25C, respectively, by 28 days. Lactic acid bacteria and Bacillus spp.were not detected throughout the 28 days storage period. Toxin was detected by days 28 and 14 at 12 and 25C, respectively, and toxigenesis preceded spoilage. The absence of toxin in cooked nuggets was attributed to the anti-botulinal role by Bacillus species, the predominant spoilage bacteria in cooked nuggets.

Notes: Packages containing chubs of summer sausage were inoculated with about 108 cfu/mL of a three-strain mixture of Listeria monocytogenes and vacuum sealed. The fate of the pathogen was then monitored after pasteurization at 150F (66C), 170F (77C), 190F (88C) and 21 OF (99C) for 0 to 240 s. Pathogen numbers were reduced by about 3 log10 cfu per gram within 30, 60, or 90s at 21 OF (99C), 190F (88C), or 170F (77C), respectively, whereas numbers were reduced by 〈2.0 log10 cfu per gram after 240 s of heating at 150F (66C). The calculated D values were 2.08 min at 150F (66C), 0.84 min at 170F (77C), 0.37 min at 190F (88C), and 0.28 min at 21 OF (99C). These results establish the feasibility of using pasteurization to control L. monocytogenes in packaged summer sausage.

Notes: Book review in this ArticleWORLD HEALTH STATISTICS QUARTERLY DALLAS G. HOOVER

Notes: Decimal reduction times (D-values) for Saccharomyces cerevisiae ascospores inoculated into pasteurized orang juice ranged from 4 to 76 s at pressures between 500 and 350 MPa. At the same pressures, D-values of S. cerevisiae vegetative cells ranged from 1 to 38 s while those for the native microflora in nonpasteurized Hamlin orange juice were between 3 and 74 s. Corresponding z-values were 123, 106 and 103 MPa for ascospores, vegetative cells and native microflora, respectively. Native microorganisms that survived high pressure treatments included yeasts, gram-positive and gram-negative bacilli. Pectinmethylesterase activity in nonpasteurized Hamlin orange juice was reduced to 5% of initial activity after 30 s at 900 MPa.

Notes: The objective of this study was to investigate awareness and attitude regarding food-related hygienic practices in the home. For this purpose and within a sanitary education program in pricary schools in a town of Central Italy, a questionnaire was used to collect information from parents of pupils. The questionnaire included questions in four major areas: personal hygiene and cleaning up procedures; meal preparation; food storage; and knowledge of key terms and concepts pertaining to food safety. Analysis of 183 questionnaires showed either risk of cross contamination, improper thawing of food, or inadequate storing and reheating of cooked foods during home food preparation and storage practice. Particularly, 73% of respondents thawed large pieces of frozen food at room temperature; 89% did not reheat cooked food after it had been stored; 75% stored raw meat and poultry in the upper shelves of refrigerators. Precise information on the lack of food safety practices will facilitate the development of proper consumer education programs.

Notes: Microbiological studies on a popular maize product (kwoka) with or without a soybean supplement (20 or 30%) were carried out during production and storage at 26–32C. Soybean -supplementedproduct had greater microbial diversity and higher populations than the unsupplemented control. The diversity was most evident at the slurry stage (blended mixture before steaming) which contained ten different microbial genera including Aspergillus, Enterobacter, Bacillus, Lactobacillus, Micrococcus and Pediococcus. A dramatic decrease occurred after steaming which killed most of the molds and Gram-negative bacteria. However, within 1 day of storage, a sharp increase was observed in the microbial population of all samples and maximum load occurred in 20% soybean supplemented “kwoka” at the end of storage. The microbiota became less diverse with storage and was dominated by Bacillus, Lactobacillus and Micrococcus. packaging of ‘kwoka’ in traditional leaves was microbiologically inferior to polyethylene packaging. Changes in the acidity of 30% supplemented ‘kwoka’ were less dramatic compared to the other products. The lactics were primarily responsible for the spoilage of the products (especially the 20% supplemented) after approximately 3 days of storage at tropical ambient temperature of26–32C.; Accepted for Publication August 8, 1997

Notes: Chicken, lamb and buffalo meat were subjected to low-dose gamma irradiation (2.5 kGy) and stored at 0–3C. Lipid peroxidation in terms of thiobarbituric acid (TBA) number and carbonyl content were monitored during storage. While irradiated meat showed slight increase in TBA number and carbonyl content on storage as compared to nonirradiated meat, this did not affect the sensory qualities of meat. Free fatty acid content decreased markedly on irradiation. Irradiated meats were microbiologically safe and sensorily acceptable up to 4 weeks in the nonfrozen state (0–3C) while nonirradiated meat had a shelf-life of less than 2 weeks.

Notes: In a nonhypothetical laboratory experiment, participants were willing to pay an average of $0.71 for the right to exchange a typical meat sandwich for a sandwich irradiated to eliminate the potential risk of foodborne bacteria. Forty-one of sixty participants (68.3%) were willing to pay some positive amount. Tobit analysis was used in order to allow for the fact that Willingness To Pay (WTP) was censored at zero. WTP was interpreted as the demand for irradiation to control foodborne disease. A positive WTP was interpreted as acceptance of irradiation. The aggregated WTP greatly exceeds the estimated direct costs of foodborne disease, and the estimated costs of irradiation for many food products. There was a positive relationship between WTP and the perceived risk of foodborne disease, and a negative relationship between WTP and years of education.

Notes: The potential of using trisodium phosphate (TSP) to reduce bacterial populations in fresh fishery products was explored since TSP has recently been approved by USDA for its usage in poultry processing to eliminate Salmonella contamination. Fresh headed shrimp and rainbow trout fillets were inoculated with L. monocytogenes before dipped in tap water, 10% TSP, or 20% TSP solutions and overwrap-packaged. Surface pH values, psychrotrophic plate counts, and L. monocytogenes counts of inoculated shrimp and trout fillets were determined after 0, 3, 6, and 9 days of storage at 4C. The TSP treatment resulted in relatively high residual surface pH values (11–12) initially in both shrimp and trout fillets. Compared to tap water dipping, TSP treatment did not significantly reduce psychrotrophic or Listeria populations in shrimp. However, the 20% TSP treatment significantly (p 〈 0.05) lowered 0-day psychrotrophic and L. monocytogenes counts of trout fillets and remained effective for 6 days during storage at 4C.

Notes: Enterohemorrhagic Escherichia coli O157:H7 (EHEC) is recognized as a frequent cause of gastroenteritis ranging from mild to severe bloody diarrhea. The Shiga-like toxin produced by EHEC can result in hemolytic uremic syndrome, now the major cause of acute kidney failure in children in the United States. Inadequately cooked beef is most commonly implicated in the transmission of EHEC, although only a small fraction of cattle appear to harbor the organism. In several studies EHEC positive herds were detected only in the summer months correlating with the occurrence of human infections. Numerous E. coli strains have been shown to enter a viable but nonculturable (VBNC) state as a result of environmental stresses, including low temperature. Using traditional plating methods and the BacLight Molecular Probe, we monitored EHEC strains incubated in river water (RW) and artificial sea water (ASW) at temperatures of 5C and 25C for their entry into the VBNC state. EHEC strains remained culturable for over 40 days in both ASW and RW incubated at 25C. In ASW, these levels were higher than a non-EHEC control. At 5C, the number of culturable EHEC cells dropped gradually in both RW and ASW. Using the BacLight Molecular Probe, we were able to demonstrate that these cells, though not culturable, were viable indicating entry into the VBNC state. Our study suggests that temperature and not salinity is the primary signal for entry into this state.

Notes: Inactivation of Escherichia coli O157:H7 by pulsed electric field, benzoic or sorbic acid, alone or in combination was investigated. When the cells of E. coli O157:H7 were suspended in 10% glycerol and treated with a single highvoltage (12.5 kv/cm) electric pulse at 25C, the count decreased by 1.1–1.6 log10 CFU/mL. Presence of benzoic and sorbic acid (1000 ppm) in the suspending medium, at pH 3.4 without electric treatment, decreased the count by 1.9–2.5 and 0.6–1.1 log, respectively. A synergistic killing effect between the high electric pulse and organic acid was observed at pH 3.4, but not at pH 6.4. When the cell suspension of E. coli O157:H7 was treated with five electric pulses in the presence of benzoic or sorbic acid at pH 3.4, the count decreased by 5.6 and 4.2 logs, respectively. Inactivation of the pathogen by combinations of electric pulse and organic acid was enhanced by an increase in temperature, field strength, and number of electric pulses, Inactivation was greater when the cells were suspended in ionic suspending media (0.1% NaCl or 5mM phosphate buffer) than in nonionic media (10% glycerol or 1% sucrose).

Notes: The prevalence of some enteric bacteria in alfalfa sprouts obtained from public markets and supermarkets in Queretaro City was determined. In addition, the antimicrobial effect of several commercial germicides was tested on alfalfa sprouts for reduction of native coliforms and inoculated Vibrio cholerae Ol or Salmonella typhi. Escherichia coli and Salmonella sp. were detected in 74% and 1.1% of 90 of samples, respectively, and no sample tested positive to V. cholerae Ol. Coliforms ranged from 7.3 to 8.5 log10 CFU/g. Treatment of alfalfa sprouts with 200 mg/L of hypochlorite, of a commercial iodophor, or of chlorine dioxide, or with 100 mg/L of Citricidal® for 5 min, reduced native coliforms only by 1–2 log10 CFU/g. Reductions of S. typhi and V. cholerae O1 with 200 mg/L of sodium hypochlorite and 100 mg/L Citricidal® were also no more than J.5 log10 CFU/g. Sprouts from seeds contaminated with V. cholerae O1 that were irrigated daily with water containing 100 mg/L chlorine dioxide, showed significantly lower V. cholerae Ol counts than seeds irrigated with tap water (p〈0.05). However, V. cholerae O1 persisted after 8 days of sprouting, when the sprouts are ready for marketing. Treatment of seeds and sprouts with antimicrobials does not appear to be effective for reducing pathogens to safe levels.

Notes: The effects and interactions of heating temperature (5–62.5C), pH (4 – 8), NaCl (0 – 6%, w/v), and sodium pyrophosphate (0 – 0.3%, w/v) on the heat resistance of a four strain mixture of Escherichia coli O157:H7 in beef gravy were examined. Thermal death times were determined using a submerged coil heating apparatus. The recovery medium was plate count agar supplemented with 1% sodium pyruvate. Decimal reduction times (D-values) were calculated by fitting a survival model to the data with a curve fitting program. The D-values were analyzed by second order response surface regression for temperature, pH, NaCl and sodium pyrophosphate levels. The four variables interacted to affect the inactivation of the pathogen. Thermal resistance of E. coli O157:H7 can be lowered by combining these intrinsic factors. A mathematical model describing the combined effect of temperature, pH, NaCl and sodium pyrophosphate levels on the thermal inactivation of E. coli O157:H7 was developed. The model can predict D-values for any combinations of temperature, pH, NaCl and sodium pyrophosphate that are within the range of those tested.

Notes: Croquette is a prepared food made with meat or fish as its basic ingredients. Since it is a perishable, heavily handled product, microbiological hazards are associated with the process. Microbiological analyses were performed throughout the commercial processing of chicken croquettes to evaluate the microbial hazards. Moderately high levels of microorganisms were observed in raw materials, but the highest plate counts were noted following extrusion of the croquettes. Pathogenic bacteria, such as Clostridium perfringens, were detected during the process. The increase in the levels of microorganisms observed after extrusion and the presence of C. perfringens were associated with the semi-solid paste called bechamel. Rapid cooling of the bechamel was critical to avoid microbial proliferation and represented an effective critical control point for the implementation of a HACCP program in the processing of croquettes.

Notes: When ozone (1.3 mM) was bubbled for 3 min in a mixture of shredded lettuce and water, counts ofmesophilic andpsychrotrophic bacteria decreased 1.4 and 1.8 log10 cfu/g, respectively. Counts of these microorganisms on lettuce, from a different batch, decreased 3.9 and 4.6 log, respectively, during 5 min of ozone treatment. Shredded lettuce was treated with gaseous ozone, or mixed with aqueous solution of ozone (1:20 w/w) with or without bubbles. For effective delivery of ozone, stirring (low and high speed), sonication or stomaching was applied during the ozonation. Washing the lettuce with water only decreased total count on shredded lettuce by 0.74–1.0 log cfu/g. When lettuce in a treatment chamber was flushed with gaseous ozone, the total count decreased 0.85 log cfu/g, but when vacuum was applied before the ozone flush, the total count decreased 0.96 log cfu/g. Bubbling ozone in water-lettuce mixture while sonicating, high-speed stirring, or before stomaching inactivated 1.4, 1.9 and 1.9 log cfu/g, respectively. In conclusion, bubbling gaseous ozone in water is the most effective ozonation method. Efficient ozone delivery to microorganisms on lettuce requires a combination of ozone bubbling and high-speed stir.

Notes: Fresh pink salmon (Oncorhynchus gorbuscha) fillets and whole Pacific herring (Clupea harengus pallasi) were stored for two weeks at 10C to determine if significant amounts of histamine were produced before the fish spoiled. Spoilage odors in salmon were moderate by day 4 and intense by day 7, while herring had detectable spoilage by day 4 and became potent by day 6. Aerobic bacterial counts increased from 4.0 × 102/g initially to 3.6 × 108/g in salmon fillets by day 14 and from 2.3 × 103/g initially to 2.7 × 107/g in whole herring by day 14. Total volatile nitrogen increased from 1.8 to 78.5 mg N/100 g in salmon and 2.2 to 23.6 mg N/100 g in herring. Histamine was not detected in salmon, while concentrations reached 54.9 ppm in herring at day 14. However, herring were considered spoiled by day 6.

Notes: This report presents results of the investigations carried out to understand the role of fat levels in fish on postirradiation recovery/survival and growth of four pathogens generally encountered in seafoods. Fish of low [golden anchoy, (Coillia dussumierij, 0.39%] as well as high fat [Indian sardine, (Sardinella longiceps), 7.1 %] content (with endogenous biota were inoculated separately with cells of Listeria monocytogenes 036, Yersinia enterocolitica 5692, Bacillus cereus and Salmonella typhimurium; and irradiated at doses of 1 and 3 kGy. The number of viable organisms for each was monitored for two weeks at 2-4C on appropriate selective media. The four pathogens studied exhibited variation in their ability to recover from radiation damage as evidenced in terms of lag period; but their recovery and subsequent growth was not influenced by the fat levels offish. No increased growth of any of the pathogens tested was evidenced in irradiated fish, when compared with nonirradiated one.

Notes: Sporulation temperature is one of the most important factors that determine the heat resistance of spores. Bacterial spores are usually more heat resistant when they are formed at higher temperatures. Sporulation temperature also influences the effect of pH of heating menstruum and the effect of different acids on spore heat resistance. Heat resistance is maximum at neutral pH and decreases with acidification, but when spores are sporulated at high temperatures the effect of acidic pH on heat resistance is lower at high heat treatment temperatures. Lactic and acetic acid decrease spore heat resistance more than other acidulants, but only when spores had been sporulated at high temperatures. These effects should be considered by canning factories of acid/acidified foods, especially in hot climate areas, where these high temperatures can be easily reached. The level of mineralization of spores obtained at different Sporulation temperatures seems to be the most important mechanism responsible for their heat resistance.

Notes: Consumer knowledge of safe handling guidelines and their reported practices assessed by a mail survey indicated consumers considered themselves informed about food safety, and most reported taking action to minimize risk from potential hazards. However, most responses were related to nutritional changes, and 20% indicated they did not know how to reduce risks from microbiological hazards. Consumers were knowledgeable about appropriate safeguards in selection and cooking specific foods, however mistakes were reported in temperature control and handling leftovers. Consumer Reports, university scientists, health professionals and science magazines were considered ihe most reliable source of food safety information. Industry advertisement appears to raise consumer concern in some areas. Educational intervention should emphasize the importance of temperature control and sanitation rather than taste to determine safety. Consumers should receive information about protective technologies like heat and irradiation pasteurization.

Notes: Results from two consumer surveys are presented. In the first, a EU FAIR (European Union Food, Agriculture and Industrial Research Programme), supported project, three-thousand consumers (500 in each of six countries, Germany, Italy, Britain, Spain, Sweden and Ireland) were surveyed in March 1997 on their attitudes to the quality and safety of three meats, beef, pork and chicken. This paper deals with the safety aspects of the survey. Many consumers in all six countries said they were eating less beef and more chicken. Overall, the Spanish and Irish appeared to be the most concerned about the safety of meat, the British were somewhat less concerned. While many were confident that the food in shops is safe, there was a sizeable minority who believed the contrary. When looking for information on the safety of meat, butchers, whether independent or in supermarkets, are the group most trusted by consumers. In terms of consumer concerns, about 60 percent of beef consumers were very concerned about hormones, BSE (Bovine Spongiform encephalopathy), antibiotics and bacteria. Pork consumers had similar levels of concern as beef consumers about bacteria, antibiotics and hormones. For chicken there was a higher level of concern about bacteria (Salmonella) (68% were very concerned) and similar levels of concern to pork and beef for the other issues. Generally, fat was the issue of least concern for all three meats. Freshness was considered to be relatively the most helpful of 7 factors used for assessing safety of meat. The country of origin and what the animal was fed were also considered to be relatively helpful. Factors considered to be relatively less helpful were price and the name of the producer. In the second study, over 1200 pre-leaving certificate Irish school children participated in autumn 1996 in a national survey assessing young people's attitudes to meat. Half of the respondents agreed with the view that eating beef means increasing the risk of getting CJD (Creutzfeldt-Jakob Disease). Those who agreed were more likely to be less frequent eaters of beef and to have reduced their meat consumption in the post-BSE period. It was found also that females were more likely to eat less meat than males and to have reduced beef consumption. The implications of some of the findings of these two surveys are discussed.

Notes: Bovine spongiform encephalopathy (BSE) belongs to a distinct group of transmissible degenerative encephalopathies (TDE) that includes scrapie in sheep and Creutzfeldt-Jakob disease (CJD) of humans. These fatal neurological diseases are caused by unconventional but uncharacterized transmissible agents that have a number of unusual properties; this includes a high degree of resistance to inactivation. The only disinfectant that appears to be completely effective against high titres of TDE infectivity is sodium hypochlorite. Exposure to 1 to 2 M sodium hydroxide has a substantial but incomplete effect, as does autoclaving at temperatures between 132 and 138C for up to an hour; however, a combination of 2 M sodium hydroxide and autoclaving, even at the more modest temperature of 121C for 30 min, appears to be completely effective. With lower titres of infectivity, less rigorous regimes may be effective. For example, although most of the rendering procedures used to manufacture meat and bone meal (MBM) throughout the European Union (EU) have been found to be incapable of inactivating BSE and scrapie agents, one method which appeared to be effective with moderate titres of BSE and scrapie agent, involved exposure to steam at 133C for 20 min. This procedure is now the only one approved within the EU for the manufacture of MBM for feeding animals, excluding ruminants; however, the UK has introduced a ban on feeding MBM to any farmed species because of the occurrence of a new variant form of CJD in the UK which appears to have been caused by the BSE agent. Although the clinical signs of scrapie in sheep are entirely attributable to neurological dysfunction, tissues such as spleen and lymph nodes are known to become infected before those of the central nervous system. In contrast, the only tissues which have been found to become infected in cattle with natural BSE are brain, spinal cord and retina. These are no longer used in animal or human foodstuff. Because scrapie agent has no known association with human disease there has been no restriction in the past on using any sheep tissues, including brain, as human food; however, it is known from experimental studies that the BSE agent can infect sheep by the oral route to cause a disease that is clinically and neurohistopathologically indistinguishable from scrapie. It is also known that the spleen becomes infected in such sheep. Sheep in the UK could theoretically have become infected with the BSE agent through the feeding of infected MBM before the feed-ban in 1988. There are now measures in place that prevent the head, spinal cord, and spleen of sheep being incorporated into foodstuff.

Notes: Considerable time, regulation and consumer concern is associated with the question of chemical residues in food. Potential residues in food span a broad range from natural contaminants (mycotoxins) through environmental contaminants (dioxins, PCBs), agrochemicals (nitrates, pesticides), veterinary drugs (anthelmintics, antibiotics), prohibited substances (hormonal growth promoters), chemicals arising in processing (nitrosamines), packaging components (plasticisers) to contaminants arising in domestic food preparation (heavy metals). The occurrence or avoidance of these chemicals as residues in food is to a greater or lesser extent under the control of the food producer, processor and consumer in the activities of growing/producing, treating, storing, processing, packaging and cooking. The fundamental question is to what extent do or can residues in food constitute a food safety hazard for the consumer. Many of these substances are regulated as to their use and as to their acceptable levels in food while others, by their nature, arise as more random occurrences and, as such, are less prone to regulation. Of particular concern to the producer, processor and retailer of food is what steps may be taken to ensure that the food supply is safe. Best practice in plant and animal husbandry by the producer, in sourcing of material and in control of food manufacturing by the processor, and in sourcing of food products by the retailer combine to assure the safety of food to the consumer. This paper describes the various classes of chemicals which can arise as residues in food, particularly agrochemicals and veterinary drugs, the usage patterns which decrease/increase the likelihood of the occurrence of residues at unacceptable levels, how and in what form(s) residues can occur in foods, and the contribution of food processing to a reduction or otherwise of residue levels in food consumed. Consideration will be given, also, to quantifying the risk posed by chemical residues in food and to a study of the results from a Residue Database and from residue monitoring/surveillance as an indicator of risk to the consumer.

Notes: This paper is concerned with processes and procedures involved in the contamination of beef, lamb and pork carcasses during slaughter. The hides of beef and the fleece of sheep are major sources of carcass contamination. The spread of pathogens from beef hides to the carcass, operatives and surfaces in the abattoir is demonstrated. Efforts to clean the hide of cattle and the fleece of sheep are outlined, with reference to the success of these treatments in reducing carcass contamination. The effect of bringing very dirty or dungy animals to slaughter is considered in terms of the effect on carcass contamination after slaughter. The influence of tying the bung (or rectum) in reducing carcass contamination is discussed, as is the use of plastic bags as an additional control in preventing pathogen spread on pig carcasses. The relationship of this revised procedure in reducing the occurrence of yersiniosis in Norway is shown. The use of a commercially automated system to tie beef bungs is discussed in relation to reducing carcass contamination. A comparison between the removal of faecal contamination on carcasses by trimming or using a new steam-vacuumized system is presented. The effect of preevisceration washing of beef carcasses is described and the rationale relating to bacterial removal using this treatment is discussed. The influence of evisceration as a source of carcass contamination is demonstrated in relation to sheep slaughter. The processes of carcass decontamination using washing with water at different temperatures, steam pasteurization and hot lactic acid are compared in relation to their ability to remove bacteria from beef carcass surfaces. Finally, the effect of line speed and the impact of technology advances on beef and sheep carcass contamination is reviewed.

Notes: During the last few years there is a growing feeling in the Dutch livestock and meat industry that it is essential to change from a product oriented to a more market-oriented production (from quantity to quality). This is mainly due to developments such as a more intense international competition, stagnant or declining meat consumption and negative pressure on the consumers’ image of meat. Counteracting these developments is only possible if every part of the production chain contributes (in close cooperation with each other) to achieve a better control of the whole production process: from conception to consumption. For a number of years an extensive research program has been carried out to set up a system of Integrated Quality Control (IKB). This has led to a “total quality concept” which includes the safety and quality of the product, the production method, care for the environment, and human and animal health. This paper discusses the basic elements (structure and content) of this quality concept. The extent of implementation of the IKB-concept depends on the particular sector, but it is at around 70% for pigs and broilers. For IKB in veal, current participation is over 90%.

Notes: The need for residue testing and controls basically derives from two imperatives, the safety of the food supply and requirements imposed in trade. Maximum residue limits (MRLs) for pesticides, veterinary drugs, intentional food additives and potential contaminants, such as mycotoxins, are set for various food commodities based on toxicological assessment. Regulatory testing on domestically produced goods reveals the prevalence of a particular residue in a specific food commodity and also serves as a means to assess the effectiveness of the product registration system, while testing conducted on imports is primarily a verification of the effectiveness of the regulatory program in the exporting country. For industry, testing is required to demonstrate due diligence or to ensure that a product meets the specifications of an export market or a specific contract. Testing programs should be appropriate to meet the intended use. A survey to determine incidence of violations requires a test that detects residues above the MRL, while a dietary exposure study requires methodology that detects residues with the maximum achievable sensitivity. Tests conducted to certify a product for export or to fulfill the requirements of a contract should ensure that the product is in compliance with the market or contract requirement. If the requirement is “no detectable residues”, a very sensitive test method may be required. In many countries, there is a developing consensus that while government has a role in conducting work that is in the public interest, such as ensuring the safety of the food supply within a level of statistical assurance, it is ultimately the producer of the food who is responsible for the safety of the product or for ensuring that the product meets market or contract requirements. Various aspects of this changing regulatory, trade and consumer environment will be considered, with examples of the roles now played by governments and industry to ensure the safety and quality of food products.

Notes: A simulation model that assesses the risk of acquiring salmonellosis from consumption and handling of chicken was created in an Excel™spreadsheet and was simulated using Risk™. The model simulated the distribution, preparation, and consumption of 1,000 chickens and was designed to determine the relationship between the level of Salmonella contamination on chickens at the processing plant exit and the risk of salmonellosis for consumers of the chickens. A scatter plot of the probability of acquiring salmonellosis from consumption of the chickens simulated versus the Salmonella load on the chickens at the processing plant exit clearly showed that highly (i.e., 〉 100 Salmonella/bird) contaminated chickens at the plant exit did not necessarily pose greater risk of salmonellosis than lightly (i.e., 〈 10 Salmonella/bird) contaminated chickens at the plant exit. Rather, greater risk of salmonellosis was realized from lightly contaminated chickens when they were temperature-abused, undercooked, and consumed by someone from the high risk population.

Notes: Transmissible Spongiform Encephalopathies, or Prion diseases, are fatal neurodegenerative diseases that affect both humans and animals. Examples include Creutzfeldt-Jakob disease (CJD) in humans, Bovine Spongiform Encephalopathy (BSE) in cattle and scrapie in sheep and goats. They are characterized by a long incubation period, ranging from months to years, and a variable length clinical course, both determined by the particular infection and the species involved. Some 170,000 cattle in the UK have been diagnosed with BSE and have been destroyed. In the rest of Europe there have also been cases of BSE, though the numbers involved are much lower. The recent potential link between BSE and a new variant form of CJD has highlighted the importance of controlling both BSE and scrapie in Ireland. Control of the disease in both cattle and sheep is complicated by the long incubation period, the lack of suitable tests and the general lack of detailed information in relation to the biology of the disease. Factors that must be considered in designing an effective control strategy include (1) better understanding of the epidemiology of the disease, (2) developing rapid and reliable tests for the disease, (3) introducing a suitable surveillance system for both BSE and scrapie, (4) minimizing the consequences for farmers that have BSE-infected animals, and (5) implementing and monitoring legislation to prohibit the spread of potentially infectious material. Each of these areas is discussed and it is proposed that the introduction of best available technology in both the diagnosis and surveillance of the national herd could form the basis for an effective program against animal prion diseases.

Notes: This paper describes an outbreak of E. coli O157:H7 that occurred in central Scotland. Edipemiological and microbiological evidence has indicated that the outbreak was comprised of several separate but related incidents, relating to the lunch (attended by around 100 people) held in Wishaw Parish Church Hall, a birthday party held in a public house on November 23, 1996 and retail sales in Lanarkshire and Forth Valley. All isolates of E. coli O157:H7 from individuals in the outbreak belonged to phage type 2 and possessed the verocytotoxin gene VT2. Two hundred sixty-two of these isolates have been subjected to pulsed-field gel electrophoresis (PFGE): all had indistinguishable profiles. There were 496 cases in total. There have been 20 deaths (all adults) associated with the outbreak, the highest number of deaths associated with an outbreak of E. coli O157:H7 infection in the world. Of these, 8 people had attended the luncheon served at Wishaw Old Parish Church on November 27, 1996. The age range of those who died was 69 to 93 years. The outbreak was investigated by the Pennington Group who concluded that the circumstances of the central Scotland outbreak, and the inevitable uncertainties that may surround outbreaks generally, provide strong justification for the precautionary, preventative measures proposed and the recommendations made.

Notes: The design and improvement of products and processes often calls for experiments where several response variables are analyzed simultaneously. Frequently, some of these variables are sensory attributes that can only be measured subjectively, through sensory evaluation panels or using expert opinion. In this paper we apply a multiresponse optimization procedure presented in Fogliatto and Albin 1997, to optimize a military food product where 24 sensory attributes are evaluated through descriptive analysis techniques. Our objective is to select the best design and operating control factors considering all attributes simultaneously.

Notes: In a double-blind crossover study, 94 symptomatic adult patients with allergic rhinitis rated sensory preferences for single exposures (2 sprays in each nostril) to three intranasal corticosteroids: triamcinolone acetonide AQ, beclomethasone dipropionate AQ, and fluticasone propionate. Each patient was given the medication and then immediately asked to use a 100-point scale to rate 13 attributes: comfort to take the medicine, medicine run-off, irritation, strength of urge to sneeze, strength of odor, liking odor, strength of taste, strength of bitter taste, liking taste, and moistness of nose and throat, and then (at least 2 min after administration) irritation, medicine run-off, and overall liking. The order of drug presentation was randomized across patients and a 30-min rest interval occurred between drug administrations. Triamcinolone was lower in odor strength than both beclomethasone and fluticasone (mean scores of 8 vs 57 and 52, respectively; P〈0.001) and the odor of triamcinolone was preferred to the odor of the two other sprays (mean score of 72 vs 55 and 55, respectively; P〈0.001). While the taste intensity ratings of the three sprays were not significantly different, the triamcinolone taste was liked more than that of fluticasone (mean scores of 55 vs 41, P〈0.04). Overall, triamcinolone was liked more than fluticasone (P〈0.05). In summary, patient preference testing has shown that triamcinolone is preferred over beclomethasone and/or fluticasone in terms of odor and taste. Such preferences may be important in treatment compliance and outcomes.

Notes: Milk powders available commercially are of different qualities. The quality deviations may be due to inherent quality of the milk which in turn is dependent on various conditions like the fat content, the processing parameters, the storage time and the packaging materials used. The various brands of milk powders have been profiled sensorily for odor and flavor and also positioned using Canonical Discriminant Analysis (CDA). The study throws light on the relative qualities of the different brands, their positive and negative points and their relative position with respect to each other. The results indicate that the various types like whole milk powder, partially skimmed milk powder, skimmed milk powder and infant milk formula cluster together into the same group but the groups are separate from each other. The dominant quality attributes for the groups are different and are discussed in relation to the directional vectors.

Notes: Differences in sensory acuity and hedonic reactions to products lead to latent groups in pooled ratings data. Manufacturing locations and time differences also are sources of rating heterogeneity. Intensity and hedonic ratings are ordered categorical data. Categorical responses follow a multinomial distribution and this distribution can be applied to pooled data over trials if the multinomial probabilities are constant from trial to trial. The common test statistic used for comparing vectors of proportions or frequencies is the Pearson chi-square statistic. When ratings data are obtained from repeated ratings experiments or from a cluster sampling procedure, the covariance matrix for the vector of category proportions can differ dramatically from the one assumed for the multinomial model because of inter-trial. This effect is referred to as overdispersion. The standard multinomial model does not fit overdispersed multinomial data. The practical implication of this is that an inflated Type I error can result in a seriously erroneous conclusion. Another implication is that overdispersion is a measurable quantity that may be of interest because it can be used to signal the presence of latent segments. The Dirichlet-Multinomial (DM) model is introduced in this paper to fit overdispersed intensity and hedonic ratings data. Methods for estimating the parameters of the DM model and the test statistics based on them to test against a specified vector or compare vectors of proportions are given. A novel theoretical contribution of this paper is a method for calculating the power of the tests. This method is useful both in evaluating the tests and determining sample size and the number of trials. A test for goodness of fit of the multinomial model against the DM model is also given. The DM model can be extended further to the Generalized Dirichlet-Multinomial (GDM) model, in which multiple sources of variation are considered. The GDM model and its applications are discussed in this paper. Applications of the DM and GDM models in sensory and consumer research are illustrated using numerical examples.

Notes: A sensory panel utilized chicken patties from Pectoralis major muscle to develop a descriptive vocabulary for warmed-over flavor. Patties were subjected to 4 different cooking temperatures and stored at 4C for up to 4 days. A list of 33 descriptive terms, developed from the literature and a preliminary sample evaluation was modified over 5 daily sessions to 18 terms with corresponding references. In the term selection process the criteria used were, that terms should; have relevance to the product, discriminate clearly between samples, be nonredundant, and have cognitive clarity to the assessors. A comprehensive vocabulary was developed that described the sensory dimensions present in the samples. Over sessions the panel was found to display dynamic changes in their use of the sensory vocabulary. Overall, panel discriminative abilities were enhanced and a process of sensory learning was observed.

Notes: The objective of this study was to determine if hedonically different sweetness levels in yogurt, determined by the ideal-relative rating methods, affected the consumption of yogurt in a sensory specific satiety test. Fifteen subjects attended a preliminary session, six taste tests and three sensory specific satiety tests. During each taste test, subjects rated yogurt with one of the three levels of sweetness (high, optimum, and low) for six attributes. During each sensory specific satiety test, subjects were offered a large serving of yogurt with one of the sweetness levels. Liking for optimum or high sweet yogurts decreased more after consumption than the liking for the low sweet yogurt, however, the consumption of optimum and high sweet yogurts was also greater, thus confounding the experiment.

Notes: The effect of a warm-up sample on reliability of attribute intensity ratings from descriptive panel evaluations was studied by: (1) using a warm-up sample prior to test samples (WU), (2) using a warm-up sample prior to test samples and providing panel consensus attribute ratings for the warm-up sample to panelists (WUC), and (3) providing no warm-up sample (NWU). The standard deviation of ratings from 7 and 4 of 11 attributes for all samples was smallest in WUC and WU, respectively. In paired t-tests, significant differences were found between duplications in 0, 1 and 4 of 11 attributes in WUC, WU and NWU, respectively. Regression analysis of percent fat vs attribute intensity ratings showed the largest R2 from 6, 2, and 2 of 10 significant regression models in WUC, WU, and NWU, respectively. To maximize reliability of descriptive analysis ratings, WUC should be used.

Notes: The beta-binomial model is combined with a Thurstonian psychometric function to obtain estimates of the parameters of a distribution applicable to replicated difference tests. A method of estimating the variance of d’obtained from these tests is provided. A formula for determining sample size, which is composed of the number of trials (or panelists) and the number of replications, to determine d’is also given.

Notes: The effect of flavor types (natural and artificial), aspartame (APM)/acesulfame potassium (Ace-K) blend ratios (50%/50% - 80%/20% sweetness contribution), and acid levels (50-70% dry basis) on flavor profiles of raspberry beverages was evaluated. Optimum flavor profiles of beverages sweetened with APM/Ace-K blends would have high fruit flavor scores, balanced sourness and astringency and minimal side tastes/aftertastes. Descriptive flavor profilists developed a lexicon of flavor/mouthfeel attributes for evaluating the samples in the design. The design was replicated 3 times. Acid level influenced sourness and sweetness scores; increasing acid levels increased sourness and slightly decreased sweetness. Natural flavor in beverages showed lower raspberry intensities across all acid levels and blend ratios than artificial flavor. APM/Ace-K blend ratio had no effect on flavor/mouthfeel attributes. Additionally, HIS side tastes were minimized across all APM/Ace-K blend ratios. The optimum natural flavor beverage would contain a 60/40 to 75/25 APM/Ace-K ratio with 58-70% acid (dry basis). Optimum artificial flavor beverages would contain 50/50 to 80/20 APM/Ace-K ratios with 57-68% acid (dry basis).

Notes: Two simple methods were followed to determine detection thresholds for the taste of substances in aqueous solution. The methods applied were: a modification of the ascending method of limits and a method based on the use of scales. Detection thresholds were calculated for the four basic tastes (sweet, salty, acid, and bitterness), umami and metallic. Reference substances for each taste were sucrose, sodium chloride, citric acid, caffeine, monosodium glutamate and iron (II) sulfate heptahydrate and the results of the two methods were compared. We found that the threshold values calculated by method ASTM-679 was within the range of concentrations identified with the scales method.

Notes: Proteins in saliva samples taken from twelve subjects immediately before and immediately after tasting astringent solutions were analyzed by high performance liquid chromatography. Although considerable variation in both the qualitative and quantitative protein pattern was observed among individuals, three peaks appeared to be common to the majority of the chromatograms. The tasting of the astringent solutions resulted in detectable changes in the protein profile of the saliva samples, observed in all the chromatograms examined, and attributed to the interactions of the saliva proteins with the astringent phenolic compounds. The appearance of a major peak at 8 min after the tasting of the astringent compounds common to most of the saliva chromatograms was attributed to the formation of soluble protein-phenol complexes.

Notes: The perceived textural attributes of an English Cheddar were measured by a trained panel at various intervals during ripening, including those corresponding to mild and medium maturation times for this variety. The moisture content and pH were also monitored. After the recommended ripening period of 50 weeks the matured cheese was significantly less springy, firmer, harder, crumblier and creamier, indicating that textural attributes are related to the age of the Cheddar. Measures beyond the recommended maturation period revealed further significant differences. Comparisons of the measures taken at mild, medium and full maturity also revealed differences in the textural properties of the different classes of Cheddar. Significant correlations (p ≥0.01) between pH and springiness, crumbliness by fingers and creaminess suggested a strong relationship between these textural attributes and the extent of proteolysis. The results of this study revealed a strong relationship between age and the textural attributes of cheddar when restricted to one particular variety.

Notes: Sensory research on kiwifruit has shown that specific sugars and acids, and volatile flavor compounds have causative effects on “sweet” and “acid” aroma and flavor attributes. New Zealand consumers (n = 162) assessed the perceived flavor intensity and acceptability of three volatile flavor compounds (ethyl butanoate, E-2-hexenal and hexanal) at varying levels in a model base solution. Increasing levels of ethyl butanoate positively affected all the acceptability attributes (“overall liking,”“liking of aroma,”“liking of flavor”) as well as increased the perceived intensity of “kiwifruit aroma” and “kiwifruit flavor.” Increasing levels of E-2-hexenal negatively affected all the acceptability attributes but increased the perceived intensity of “kiwifruit aroma” and “acid flavor.” An increase in hexanal increased perceived intensity of “kiwifruit aroma.” Ethyl butanoate and E-2-hexenel at the levels tested had the most prominent effects on consumer perceived intensity and acceptability of the “kiwifruit flavor.”

Notes: Wine vinegar is a product obtained from wine acidification which contains at least 5% by wt. of acetic acid, in general without any additives or colorings.Aspects studied in this work include: the determination of the taste group thresholds (geometric mean of the individual best-estimate thresholds “BET”) of two different acids (citric and acetic acids) in aqueous solution and spanish vinegars produced from table and sherry wines. The results obtained suggest that wine vinegar can be considered something more than just an acidulant agent.In order to evaluate differences among wine vinegars, discriminant tests for twenty-five spanish vinegars (sherry, table and flavored vinegars) were applied. Six of the twelve attributes freely chosen by assessors allowed grouping of the spanish wine vinegars according to their sensory aspects.

Notes: Expectations are generated by a variety of factors. We indicate a flow chart for the role of expectations at the point of choice and in influencing sensory perception at the time of consumption. We review the sparse literature on how advertising, packaging and information generate sensory expectations. The application of various theories to explain the observed effects of sensory expectations are reviewed. There is overwhelming evidence for assimilation-contrast effect, although no studies have been specifically designed to detect it. Finally we review the reasons why individuals might differ in the way that expectations influence sensory perception. These reasons include ideas from persuasion literature and private body consciousness. A number of behavioral hypothesis that follow from these theories are developed.

Notes: Seventy-nine children ages 36–71 months evaluated 2% commercial UHT milk and 2% commercial pasteurized milk for taste, color and mouthfeel with age appropriate facial hedonic scales with Peryam and Kroll verbal descriptors. Children significantly preferred the pasteurized milk over UHT milk for taste and mouthfeel attributes. Descriptive analysis of milks with an adult trained panel showed a significantly higher cooked note in UHT milk products which may explain the difference in preference. The results also showed that children 36–47 months were able to use the 3-point scale; children 47–59 months the 5-point scale; and children 60–71 months the 7-point scale to score preferences for food. Data transformation for a 0 to 100 point scale provided ease of comparison between age groups. Using the appropriate testing instruments, young children were able to provide valid food preference information.

Notes: This paper compares experts and consumers to determine the degree to which they agree with each other on ratings of 37 sauce products, using the same sensory attributes. The paper also assesses the degree to which sensory attribute ratings correlate with objective physical measures. The ratings of experts (1-9 scale) and consumers (0–100 scale) agree quite highly, as shown by the high correlation between the two panels across the 37 products. The paper refutes the notion that consumers are incapable of validly rating the sensory aspects of products. The paper therefore presents the case for using consumers to assess the sensory characteristics of products.

Notes: The purpose of this study was to assess the sensory characteristics of sodium lactate (SL) in combination with sodium tripolyphosphate (STP) in a model system at common usage levels for meat products. Using a gelatin-based (2%) system containing various concentrations of sodium lactate (0%, 1%, 2%, or 3%) and sodium tripolyphosphate (0%, 0.1%, 0.2%, 0.3%, or 0.4%) a thirteen-member trained sensory panel scored samples for saltiness, bitterness, and soapiness. As sodium lactate and sodium tripolyphosphate levels increased, saltiness increased. Bitterness decreased with addition of 1% SL and increased with 2 and 3% SL. Soapiness also increased with increasing levels of SL. Bitterness and soapiness were not affected by increasing STP concentrations.

Notes: The impact of 2-methylisoborneol (MIB) (earthy/musty), on the flavor evaluation of farm-raised catfish was assessed by a descriptive analysis panel, who are trained to evaluate flavor intensity using universal scales. Ideally, panelists should give the same intensity ratings for all attributes within a sample. Realistically, individual panelists perceive flavor intensity differently, because of variations in detection thresholds, adaptation, fatigue and enhancement or suppression. Experiments were designed to investigate problems associated with evaluating catfish flavor. Samples “spiked” with MIB had lower chickeny flavor than unspiked. Intensities of MIB in spiked samples that followed an equally spiked sample were lower. Problems can occur when catfish are presented at intervals less than 7 min. Panelists experienced difficulty in determining intensity differences of MIB flavor between sessions, but could determine differences in intensity of MIB within a session. These influences must be accounted for in experimental designs to assess catfish flavors.

Notes: Salivation may affect texture and taste perception. Thus, any influences that affect salivation also might affect a panelist's sensory responses. Twelve sensory panelists were compared for psychophysiological factors that might influence their salivary responses. Medication, body mass index (Quetelet), dieting-induced deprivation, nutrient deficiency, and caffeine, tannin, and fiber consumptions along with smoking were considered. Specific nutrient deficiencies or fiber consumption did not affect salivation of the panelists studied. All other factors, especially smoking and diet-induced deprivation, appeared to warrant further study with a larger population.

Notes: The objective of this study was to compare data obtained using descriptive analysis (DA) and free-choice profiling (FCP) of a simple model solution. Three menthol isomers (l-, d-, dl-), each at 0.01, 0.02, and 0.04% (w/v), were tested. A trained DA panel (n = 11) used two aroma, three nasal-sensation, two taste, and five mouth-sensation terms to describe the samples. An untrained panel (n = 15) used FCP to assess the same solutions. Individual FCP panelists used from nine to twenty-one terms. All DA terms significantly discriminated among the samples. Seven to eighteen of the FCP panelist descriptors significantly discriminated among the samples. Procrustes analyses (PA) indicated that FCP and DA similarly discriminated among the samples, possibly because the solutions were essentially one dimensional. Sample loadings on dimension 1 of both spaces were correlated (r = 0.966) as were dimension 2 loadings (r = 0.783). The FCP Rc-value was 91.2% and the DA Rc value was 85.6%. At higher concentrations (0.04 and 0.02%) l-menthol was significantly stronger than d-menthol in eucalyptus aroma, nasal clearing, all mouth cooling attributes, and bitter attertaste. At 0.01 % concentration no significant differences were detected among the menthol isomers.

Notes: Nonparametric models for sensory discrimination methods are developed. In these models, the relationship between the probability of a correct response, Pc, and the measures for sensory discriminability or sensory difference, p1 and p2 are given. On the basis of the models, different sensitivities for triadic tests were compared including 3-AFC and triangle methods with the strong stimulus as the odd sample and with the weak stimulus as the odd sample. Predictions were made which can be tested experimentally.

Notes: A table is provided for testing the significance of R-index values. The use of the table is illustrated and the theory and assumptions behind the method are explained.

Notes: There are many ways in which a laboratory difference test differs from ‘real life’ discrimination of foods. One of these is the interval of time between tasting the two stimuli to be discriminated. To investigate this, judges performed same-different discrimination tests using a citrus flavored beverage as a medium. The time interval between tasting the standard and comparison stimuli was varied. In this initial study, short intervals of zero, 30, 60 s were examined. For judges unfamiltar with the stimuli, performance deteriorated as the time interval increased. For judges familiar with the stimuli, the zero time interval elicited best performance but there was no decrease in performance when the interval was increased from 30 to 60 s. The results were explained by hypothesizing different types of memory trace for the standard stimulus being utilized for comparison with the comparison stimulus.

Notes: To determine quality characteristics of snack chips, six snack chip prototypes containing cowpea flour, cornmeal, wheat flour and cornstarch (26, 34, and 42%) were formulated. Desirable characteristics as determined by three focus groups were a golden yellow color in a thin, smooth corn-chip form with crunchy or crispy texture, greaseless or dry mouthfeel and salty corn flavor. Chips were undesirable if brown-colored, thick, oily or greasy, had either hard or crumbly texture, and had bland, fishy, or burnt flavors. In consumer acceptance tests, commercial products were found to be more appealing than the experimental products. A discriminant model based on instrumental measurements of color and texture from 11 snack chip samples (six prototypes and five commercial samples) correctly grouped 100% of the acceptable and 90% of unacceptable products.

Notes: To find selective and predictive tests in texture profiling, a series of 20 tests and 2 texture profiles were submitted to 25 subjects. Selection was carried out according to ranking, scoring and a texture property knowledge questionnaire. Two profiles were then done on 5 Bolognese sauce and 8 rice samples. Assessors were assessed by Spearman correlation coefficients for ranking tests, F values for scoring, average square canonical correlation coefficients for measuring the dimensionality of individual sample space, product discrimination and response repeatability for both Bolognese sauce and rice samples.Characterization test results showed that subject ability varied widely according to the test and the profile. Only one significant relationship between the texture property knowledge test and rice profile performances was found. More tests were successfully related to one or several texture attributes of both profiles. The ability to complete a complex profile could be discerned, albeit with difficulty, through simple selection tests.

Notes: Instrumental measurement of color places hue in a 360° continuum, but sensory description of color usually refers to distinct hues — red, green, yellow etc. Color evaluation of “Golden Delicious” apples by both an instrumental method and an experienced sensory panel was conducted to determine if sensory panelists perceive changes of golden apple color in green and yellow hues separately or on a hue continuum from green to yellow. Apple color changed from green to yellow during storage. Two different sensory scoring ballots were used to determine if sensory panelists view color in discrete green and yellow hues or on a green-to-yellow continuum. Data collected from this study demonstrated that sensory panelists can detect the color changes of decreasing greenness, increasing yellowness, and color change from green to yellow in an equal fashion. Hue angle represented the best predictor of sensory color perception.

Notes: Interindividual differences in sweet and bitter taste sensitivity were investigated using time-intensity (TI) measurements and multivariate statistics. TI profiles were obtained in triplicate from 25 subjects for 23 sweet and/or bitter stimuli first matched to be approximately equi-intense to 200 mM NaCl. Sweet stimuli, except for the larger sweeteners, were less persistent, and required less time to reach maximum intensity than bitter stimuli. The results of principal component (PCA) and cluster (CA) analyses of the stimuli X subjects matrices for maximum intensity (Imax), time to maximum intensity (Tmax), total duration (Tdur), and area under the curve (Area) suggest that sweet and bitter stimuli do not share common receptors; and that there are at least two receptor mechanisms each for sweet taste (one for sugars and other small compounds, and the other for large sweeteners) and bitter taste (one for PTC/PROP and one for other bitter compounds).

Notes: The objective of this study was to assess the sensory characteristics of potassium lactate (PL) in combination with salt (NaCl) in a model system at common usage levels for meat systems. Using a gelatin-based (3%) model system containing various concentrations of potassium lactate (0%, 1%, 2%, and 3%) and sodium chloride (0%, 0.5%, 1%, 1.5%, 2%, 2.5%, and 3%), a sensory panel (10) selected for salt sensitivity (0.08% threshold or less) scored the intensity of saltiness and bitterness of each treatment combination using a scale of 0 = none and 15 = intense. As salt concentration increased, saltiness increased and bitterness decreased; as PL increased, saltiness and bitterness increased. At 2% salt, the bitterness of PL was masked; however, salt concentrations below and above 2% were less effective in bitterness reduction.

Notes: Multidimensional scaling (MDS) procedures produce maps of stimulus points, the dimensions of which may be sensory and/or physicochemical attributes. Our objective was to test the efficiencies of a cyclic design and a MDS method in the study of saltiness perception. Two levels of NaCl (0.1% and 0.2%, w/v) were added to two nonionic and two ionic gum solutions prepared to two concentrations. Subjects scaled dissimilarities between pairs of solutions and rated each sample for flavor attributes. Solution pairs were selected using cyclic designs. Repeated measures ANOVA determined that added NaCl was the only significant factor affecting saltiness perception. In contrast, from KYST-2A MDS maps, we concluded that saltiness perception was influenced by gum property, gum concentration, presence of calcium and potassium, and related to binding of the sodium ion (Na+) as determined by23Na nuclear magnetic resonance (NMR) spectroscopy. The MDS cyclic design successfully reduced the number of samples and subjects when using experienced subjects.

Notes: Between pH 2 and pH 10.5 the titration curve of washed native cod myofibrils can he accounted for solely on the basis of the probable dissociation constants of the carboxyl, histidyl, lysyl, and tyrosyl groups of the constituent proteins. On heat coagulation of washed cod myofibrils, a slight shift in the titration curve toward more alkaline pH's occurs, particularly between pH 4.5 and 7.0, but no evidence was obtained for experimentally significant changes in the numbers of titratable acid or basic groups. The titration curves of cod myofibrils prepared from fish stored at −14° for periods from 1 week up to 2 yr are very similar, and no evidence was obtained for loss of titratable acid or basic groups during frozen storage. The changes that occur in the titration curve of beef myofibrils on heat coagulation are similar to those occurring in the titration curve of cod myofibrils.

Notes: The hypoxanthine contents of fresh fillets taken from three species of fish in Pacific Northwest waters were found to he almost zero, and increased at a fairly uniform rate during the first 8-10 days of storage in melting ice. The hypoxanthine content reached maximum values in about 8-10 days. Total nucleotides reached a minimum in about 6-8 days. Fillets stored at −20°F showed practically no change in hypoxanthine content during four, months of storage.Hypoxanthine can be rapidly measured and the data can be used to judge the length of time fish has been held in storage.

Notes: The activity of succinic dehydrogenase of post-rigor bovine tissue was determined at various temperatures and pH values. The oxygen uptake thus measured yielded typical curves. In the first 15 hr the uniform gas uptake can be accounted for by oxygenation of myoglobin, solution of oxygen and nitrogen, and enzymatic oxygen uptake. After 15 hr the oxygen uptake is due to enzymatic reaction. The enzymatic uptake of oxygen is about 0.7 μL/hr/g of wet tissue. The evolution of carbon dioxide was about 1.1 μL/hr/g of wet tissue. Tissue sample taken from deep in the musculature, however, showed a larger carbon dioxide evolution in the first 4 hr of exposure (before equilbrium is established) to au air atmosphere.

Notes: The heat resistance of Salmonella typhimurium in liquid whole egg at pH 5.5 and 55°C was reduced significantly by a number of chemical additives. Of these, the most effective were β-propiolactone, ethylene oxide, and butadiene dioxide. Additional advantages of ethylene oxide and β-propiolactone were the elimination of S. typhimurium from heavily inoculated whole-egg slurry during storage at 0°C and a markedly increased lag phase of growth of the test organism in egg incubated at 30°C. Butadiene dioxide, although not tested at 0°C, was most effective in reducing heat resistance at pH 5.5 and 55° C, and also greatly increased the lag phase of the test organism at 30° C. Unfortunately, this latter compound is carcinogenic to mice.Acetic or lactic acid, used to lower the pH of liquid whole eggs, decreased the heat resistance of S. typhimurium more effectively than did hydrochloric acid, especially at pH 5.5 arid 6.0. Formic and propionic acids also were more effective than HCl when all were tested at pH 5.5. Differences in degree of dissociation between hydrochloric and the organic acids are thought to account, in large measure, for these observations.

Notes: Bacillus subtilis strain 5230 endospores suspended in water at a concentration of ca. 1 × 108 spores per ml were heat-activated at eight temperatures ranging from 5 to 94°C. The response was measured by plate count and recorded as the beat-activated decimal fraction of the total viable count. The method for determining total viable count ineluded a medium containing CaCl2 and Na2 dipicolinate. This medium enumerated total viable populations, which were equivalent to total direct microscopic counts, without the usual beat-treatment requirement. A method was developed to evaluate the contribution by the plate-count incubation to the total heat treatment. The exposure times were corrected to compensate for the incubation heat treatment. The heat-activation response was obtained throughout the entire range of test temperatures; however, the exposure time required to achieve the response was extended as temperature was decreased. The logarithm of the rate of heat activation was related to the test temperature, i.e., at a lower temperature, a longer time was required for the response. The thermo-dynamic properties for the system were: ΔH

Notes: Spores of Bacillus megaterium 1A28 and B. polymyxa 1A39 were heated at 100°C in buffers adjusted to different pH values. Generally, recovery of survivors was greatest in the neutral zone. Variations in recovery of survivors were attributable to the organism, buffer constituents, and pH of the buffer system. Use of different phosphate salts had no influence on destruction; stability was greatest in a range of .005—.050M phosphate. Citrate, phthalate, or ammonium ion in the buffer usually reduced heat resistance of the spores below that demonstrated in phosphate buffer.

Notes: Volatile compounds isolated from dry-cured hams were tentatively identified by gas chromatography retention times and further verification of the compounds made by infrared spectroscopy. These compounds were as follows: formaldehyde, acetaldehyde, propionaldehyde, isobutyraldehyde, n-valeraldehyde, isovaleraldehyde, acetone, diacetyl, methyl ethyl ketone, formic acid, acetic acid, propionic acid, butyric acid, and isocaproic acid. RF values and selective indicators were used to identify ammonia and methylamine. Selective trapping was used to identify hydrogen sulfide and trace amounts of disulfides and/or monosulfides.

Notes: Polarized microelectrodes were utilized as sensing devices, analogous to the human olfactory hairs, for qualitative and quantitative responses to volatiles. The measured response current is attributed to the interaction of a volatile with an electrical double layer at the electrode interface. The use of different microelectrode metals, electrolytes, and impressed voltages makes possible different electrical double-layer phenomena. With the use of only a few of the many possible combinations of electrode metals, electrolytes, and impressed voltages, differential-response sensitivity was obtained for a variety of volatiles at any given microelectrode condition. A comparison of the responses of several odorants at a number of different electrode conditions demonstrated a differential-response specificity similar to that thought to occur in the human at different olfactory receptor sites.

Notes: Textural changes of pears and peaches exposed to gamma radiation of 300, 600, and 900 Krads were found to correspond to a decrease in proto-pectin content and an increase in pectin and pectate fractions of the fruits. Characterizations of the 700% alcohol-insoluble solids prepared from these fruits revealed only minor differences in respect to their anhydrouronide and acetyl content and degree of esterification. To account for the marked effects of radiation, activities of pectic enzymes extracted from irradiated fruits were investigated. Pectin methylesterase showed an increased activity immediately after doses of 300 and 600 Krads, and enzymes extracted from fruit four days after irradiation had a reduced activity. Pears, peaches, and nectarines irradiated under nitrogen atmosphere softened much less than fruits irradiated under air. While this may be attributed to the reduced formation of free radicals under anoxic conditions, a further experiment with pectin solutions exposed to gamma radiation under similar atmospheric conditions did not support this suggestion. The changes in 1% pectin solutions were related to radiation dose, but were remarkably similar regardless of the presence or absence of oxygen during exposure.

Notes: The liver lipid fatty acid composition of animals raised on pork rations was determined and compared with that of animals raised on a stock ration. The pork rations contained approximately 25% crude lipid, the proportion of oleic acid being 46–50%. The relation between the dietary and liver lipid fatty acid compositions was evaluated, with the most striking relationship being that between dietary and liver lipid oleate/linoleate ratios. The tissue levels of oleic, linoleic, and arachidonic acids provided supporting evidence for the existence of a competitive effect of oleic acid in the conversion of linoleic to arachidonic acid. The results suggest that the dietary oleate/linoleate ratio is of importance in essential fatty acid nutrition in rations containing appreciable quantities of oleic acid. The sex variable, as it applies to the relation between dietary and liver lipid, was also evaluated.

Notes: A model system of thin films of lipid supported on dry gelatin plates was used for studying rates of lipoxidation. Variations in the nature of the gelatins used in the supporting surfaces showed significant differences in protective action against lipid oxidation. It is suggested that the observed differences may be due to differences in the orienting effects of the surfaces. Gamma-tocopherol was found to be an effective inhibitor of the oxidation of the films. Synthetic phenolic antioxidants were not nearly as effective. Phospholipid in large concentration was also an effective inhibitor.

Notes: Because of the limited penetrating ability of low-voltage electrons, depth and density are necessarily major considerations in the experimental irradiation of food by this means. In this study, survival of bacteria dispersed in agar was used to indicate the effective amounts of irradiation resulting at various depths from various electron doses to the surface. The per cent survival at each depth was plotted against the dose received as measured by cobalt glass dosimeters located at the same depth. These had been calibrated in terms of dose response by means of gamma radiation delivered by a source accurately calibrated by ferrous dosimetry. Within the 3-cm depth studied, a linear relationship was found between dose and log per cent survival.

Notes: Slices of beef were heated to 130°, 150° and 195° F, irradiated at 0.1 and 5.0 megarads and stored at 34° F. The effect of these variables on free amino nitrogen, total soluble nitrogen and TCA-soluble nitrogen was determined at 15-day intervals during the 60-day storage period. Increases in heating temperature reduced the rate of release of TSN and TCA-soluble fractions. Amino nitrogen was reduced only at highest temperature employed. Irradiation increased the rate of release of these fractions. The release of amino nitrogen began immediately upon storage of raw beef. Major amounts of TSN were not released until after 15 days storage and TCA-soluble nitrogen not until after 45 days storage. This suggests successive fragmentation of the initially bound protein.

Notes: Color data on stored spinach and cauliflower were correlated with judges’scores to determine best sampling procedures for measurements with the Hunter Color and Color-Difference Meter. Spinach stems, rather than leaves or mixtures, changed the most and most uniformly, correlated best with scores, and produced the smallest experimental errors. Cauliflower floret surface, instead of stems or mixture, gave smallest significant differences by judges. Good results on the instrument were obtained for both floret surface and a rapidly prepared slurry from a thin surface layer. Best of six color indices of deterioration were Hunter “a” and hue angle

Notes: The total carotenoid pigments of pineapple fruit contain a high proportion of epoxide groups which are readily isomerized to furanoid forms in an acid but not an alkaline environment. This isomerization causes a characteristic hypsochromic shift in the absorption maxima of the pigment extract. The absorbance at 425 mμ remains relatively unchanged as isomerization proceeds, and thus can serve as a measure of the total carotenoid pigment regardless of its isomeric form. The sharp maximum at 466 mμ is lost as isomerization progresses. Thus, the ratio of absorbances at 466 and 425 mμ can serve as a measure of the extent of isomerization of the pigments.

Notes: Two types of soft surface ripened cheese become inhibitory to microbial growth after storage at 2 to 4° C for 8 weeks. The antimicrobial agent has been concentrated 4- to 16- fold by aqueous extraction and lyophilization or drying by a current of air. The total antimicrobial activity of aged surface ripened cheese of the described types was estimated to be at least 18.6 antimicrobial units per gram of product.The active principle inhibited growth and toxin production of type A Clostridium botulinum 62A, the growth of Staphylococcus aureus 223 and Bacillus cereus 800/58. Threshold subinhibitory amounts of the antimicrobial concentrates stimulated growth of these organisms.

Notes: pH and temperature in muscle during the onset of rigor mortis as well as gross morphology of muscle 24 hr post-mortem were related to fluid losses and associated properties during refrigerated storage, cooking, and thawing. When rigor mortis onset occurred at pH values below 5.9 and temperature above 35°C, the longissimus dorsi muscle became pale and exudative. Evaporative cooking losses amounted to 40–45% of the sample weight and resulted in slow cooking rates and high shear-force values. Conversely, when the onset of rigor mortis occurred while pH values remained above pH 6.0 the muscles were dark and firm, with superior juice-retaining properties. Less than 20% of the sample weight was lost by evaporation during cooking, allowing the muscle temperature to rise at about twice the rate found for pale exudative muscle. Some muscles were found to be exudative and have low pH values (5.2) while retaining a dark red color. These muscles were found to have storage, cooking, and organoleptic properties similar to those found for pale exudative muscle. Storage of muscle samples at either 0°C or 6°C did not improve color, pH, juice retention or cooking characteristics. Gross morphology of muscle chilled 24 hr was associated more closely with thaw drip formation than with freezing or thawing conditions.

Notes: Thirty-seven Poland China pigs of uniform weight were subjected to various (warm, cold, warm-cold) ante-mortem treatments. The warm treatment (42–45°C) resulted in rapid post-mortem glycolysis, rapid onset of rigor mortis at a low pH and high temperature, and the development of extremely pale, soft, and exudative musculature with a marked loss in juice retention and protein solubility. Although muscle characteristics improved markedly from cold treatment (1–3°C), the most desirable muscles were produced by the warm treatment followed immediately by cold treatment. The latter treatment resulted in lower muscle temperature and reduced levels of glycogen and certain glycolytic components at the time of death. These muscles exhibited a limited glycolysis, rapid onset of rigor mortis but at a low temperature and high pH, and appeared dark, dry, and firm, with superior juice retention and greater protein solubility. The cold-to-warm treatment failed to provide uniformity in the development of post-mortem changes in color and structure.

Notes: Studies were undertaken to determine the effects of iron on the microbiological quality and fluorescence of poultry dipped in solutions containing different concentrations of the metal. When pseudomonads were grown in different broth media, fluorescent pigment production differed with bacterial species, amount of iron, and medium used. Growth was inhibited by the chelating agent, 8-hydroxyquinoline; inhibition was reversed by addition of iron. When chicken was dipped in solutions containing 0, 0.1, 1, and 5 ppm iron, and stored 1 week at 5°C, fluorescence was greatest in broth inoculated with organisms from poultry treated with the two highest concentrations. Bacterial growth was also greatest on chicken in the presence of 1 ppm added iron.

Notes: The protein quality of baked whole-wheat bread and of the unbaked ingredients was estimated from: 1) change in body weight of rats; 2) protein efficiency ratio; 3) biological value (nitrogen-balance method); and 4) net protein utilization (change in carcass nitrogen). Steamed bread was evaluated by methods 1, 2, and 4. By all methods, the protein quality of baked bread was significantly less than that of the unbaked ingredients. Differences ranged from 9 to 53%, depending on the method of testing. The protein quality of steamed bread was the same as, or slightly less (0 to 9%) than, that of the unbaked ingredients.

Notes: A highly trained panel of nine judges determined the taste interactions of supra threshold concentrations of sucrose, sodium chloride, and citric acid in lima bean purée. The results were in good agreement with previous results with solutions of distilled water, in which: 1) sucrose and citric acid exhibited a mutual masking effect, and 2) sucrose and sodium chloride produced mutual masking except for low levels of sodium chloride (0.05 and 0.10%), which slightly enhanced the apparent sweetness of 0.4 and 0.8% sucrose. Sodium chloride generally depressed sourness, but citric acid significantly increased the saltiness of all levels of sodium chloride. The large amount of individual-judge variation, especially in the acid-salt comparisons, is discussed.

Notes: The bleaching of anthocyanins by sulfur dioxide is a reversible process that does not involve hydrolysis of the 3-glycosidic group, reduction of the pigment, or addition of bisulfite to a ketonie, chalcone derivative. In sulfite decoloration the reactive species is the anthocyanin carbonium ion (R+). The experimental evidence indicates that this simply reacts with a bisulfite ion to form a colorless chromen-2 (or 4)-sulfonic acid (R-SO3H), similar in structure and properties to an anthocyanin carbinol base (R-OH).