ALBERT

Notizen: The emulsifying capacity curves for actin, myosin, actomyosin, and sarcoplasmic proteins were determined under various conditions. The proteins were ranked from greatest emulsifying capacity to least as follows: actin in the absence of salt, myosin, actomyosin, sarcoplasmic proteins (water extracted), and actin in 0.3M salt.Myosin and actomyosin produced emulsions with superior stability; however, at the pH of normal fresh meat (5.6–5.8), the sarcoplasmic fraction produced the most stable emulsions. Actin produced very stable emulsions under all conditions. The amount of protein utilized in the formation of an interface appeared to be related to the stability of au emulsion. NPN compounds were found to have no role in emulsion formation.

Notizen: Twenty-four Hereford steers were used to determine the effect of periodic electrical stimulation and limited feeding prior to slaughter on the chemical composition of the liver and certain muscles, which included the longissimus dorsi, psoas major and quadriceps femoris. Periodic electrical stimulation and limited feeding significantly increased the glycogen concentration of the liver. Periodic electrical stimulation significantly decreased the glycogen concentration in all three muscles studied. Limited feeding significantly decreased the glycogen concentration in the longissimus dorsi and quadriceps femoris muscles. Periodic electrical stimulation and limited feeding significantly decreased the lactic acid concentration in the psoas major and quadriceps femoris muscles. These treatments also produced small changes in all chemical components except sodium, in either the liver or the various muscles studied.

Notizen: Electron microscopy was used to follow changes in porcine muscle during the 24-hr post-mortem chilling period. Ante-mortem subjection to elevated temperatures or to elevated temperatures and then chilling was used to produce different rates and magnitudes of change in post-mortem muscle color, texture, and water binding. Normal muscle exhibited a gradual disruption of sarcoplasmic components, with little if any change in the myofibrils. Muscle that went into rigor rapidly at a low pH and high temperature ultimately appeared soft, pale, and watery, and electron micrographs revealed a rapid disruption of sarcoplasmic components and some disorganization of the myo-filaments. Muscle that went into rigor rapidly at a high pH and a reduced temperature ultimately appeared dark, firm, and dry, and electron micrographs revealed a high degree of organization and preservation of myofibrillar structure.

Notizen: The solubilities of sarcoplasmic and myofibrillar proteins were determined at the time of slaughter, onset of rigor mortis, completion of rigor mortis and 24 hr after death in muscles exhibiting a wide range of physiological conditions during the post-mortem period. Muscle protein solubility was grossly altered by the conditions of both temperature and pH which existed at the onset of rigor mortis or during the first few hours after death. Sarcoplasmic protein solubility at 24 hr was decreased to 55% of that found at 0 hr in muscle groups exhibiting high temperature and low pH at the onset of rigor mortis. Conversely, only a 17% reduction of sarcoplasmic protein solubility was noted in groups with high pH at onset. Myofibrillar protein solubility ranged from no reduction during the first 24 hr after death when pH remained high at onset to 75% reduction in muscle with low pH and high temperature at the onset of rigor mortis. The 24-hr pH of the muscle appeared to have only a minor influence on protein solubility. Muscle protein solubility appeared to be one of the major factors affecting the juice-retaining properties of muscle.

Notizen: Spores of Bacillus subtilis var. niger and B. stearothermophilus irradiated in nitrogen were killed in greater numbers in the presence of vitamin KC, 4.amino-1-naphthol, or 2-amino-1-naphthol than when irradiated without chemical. When irradiation was performed in air, the chemicals were without effect, or even protective. Spores of both organisms were particularly sensitive when irradiated in nitrogen with 4-amino-1-naphthol.Irradiation of Micrococcus radiodurans in anoxia with these naphthol derivatives gave losses in cell recovery that resulted in much lower populations than could he attributed to chemical toxicity per se. These chemicals were found to be toxic to a yeast that had been isolated from frozen orange juice when the preparations were in buffer of pH 7.0 and 4.0. When the yeast was suspended in orange juice, on the other hand, the chemicals were neither toxic nor radiosensitizers. Milk was also found to interfere with the bactericidal and radiolethal activities of these chemicals. Sulfhydryl compounds were shown to decrease radiolethal action.

Notizen: Two techniques of odor testing, olfactometrie vs. sniffing, were compared with propionic acid used for the test odor. The olfactometer was more rapid and reliable as a technique for odor testing. Subjects appeared more sensitive by the sniff-method, hut there were discrepancies in the data. The vapor phase above solutions of propionic acid in mineral oil was studied with propionic acid-l-C14. Evidence is presented for the existence of non ideal solutions. The significance of these data is discussed in terms of present techniques for odor testing, and their implications for future olfactory investigation.

Notizen: The effect of time and temperature on the shear patterns of small cylinders from individual choice-grade beef semitendinosus muscles, heated for several hours at 1°C intervals between 50 and 90°C is described. Beef semitendinosus muscle undergoes a marked decrease in shear, approximately one-half completed in 11 min at 58°C. This change in shear is a time-temperature rate process having a very high temperature dependence. Minimum shear values were obtained in the range of 60–64°C after heating for 30–60 min. In this time-temperature range the collagen shrinkage reaction is completed quickly while the hardening associated with higher heating temperatures is avoided. Relatively large differences, attributed to undefined biological differences, were noted in the shear versus heating time patterns for semitendinosus muscle cylinders from different animals.

Notizen: A highly trained taste panel was used to establish the concentrations of fructose, glucose, and lactose equivalent in sweetness to sucrose at threshold and suprathreshold concentrations. The same panel established the sourness of lactic, tartaric, and acetic acids equivalent to that of citric acid at threshold and suprathreshold concentrations. There was no relation between pH, total acidity, and relative sourness. Results obtained from determinations made in water solutions agreed favorably with values reported in the literature. The threshold measurements are considered to be of limited value since the relative taste intensity of these compounds is not a constant but is materially affected by the absolute concentration chosen for comparison. The presence of a slight bitterness in glucose, and a slight, unidentifiable flavor in lactose, appeared to influence the threshold determinations. When the sweetness of sucrose and fructose were compared in pear nectar, fructose was less sweet than sucrose at all concentrations (1.0–20.0% sucrose). Increasing the total acidity of the pear nectar had little or no effect on the relative sweetness of these two sugars.

Notizen: Qualitative and quantitative analyses of the fatty acids of the various lipid fractions of raw and fermented cabbage and Brussels sprouts were made by gas-liquid chromatography of the methyl esters.The amount of free or non-esterified fatty acids increased considerably in the lipid fractions of both vegetables as a result of fermentation. The unsaponifiable matter, and the fatty acids of both the acetone-soluble and acetone-insoluble fractions of the vegetables, decreased during the fermentations.Free or non-esterified palmitic acid increased significantly during fermentation—from 0.63 to 6.87% of the total fatty acid lipid in the cabbage fermentation. Results were similar in Brussels sprouts. During fermentation, the unsaturated C18 fatty acids decreased while the shorter-chain fatty acids increased. As a result of fermentation, a change was observed in the waxy or shiny appearance of the cabbage. The presence of longer-chain saturated fatty acids in the non-esterified fatty acid fraction of the fermented material has been attributed to the changes in the unsaponifiable fraction. These longer-chain fatty acids were notably absent from the fatty acids of the acetone-soluble and acetone-insoluble lipids of the unfermented vegetables.The data suggest that the changes in the lipid fraction during fermentation were effected primarily through the metabolic activities of the various lactic acid bacteria. Since it is known that many of the lactic acid bacteria require certain fatty acids for growth, it has been postulated that the changes in the lipid fraction could influence the growth and sequence of the various bacterial types that are observed in a particular fermentation.

Notizen: The effects of temperature, wax emulsion coating, hormone treatment, and their combination on the storage behavior of Nagpur and Darjeeling mandarins were investigated. Use of 2,4-D with wax coating was more effective in prolonging the storage life of both varieties at any storage temperature than either wax coating or 2,4-D used separately. The storage lives of Nagpur and Darjeeling oranges were respectively 50 and 35 days at normal temperature (50–85°F) and 90 and 75 days at 40 ± 1°F when treated with 2,4-D (1000 ppm for Nagpur and 2000 ppm for Darjeeling varieties) followed by wax coating. Wax-coated Nagpur and Darjeeling oranges were in a good marketable condition for 30 and 22 days, respectively, at room temperature, whereas the respective controls remained marketable for only 10 and 7 days. At 40 ± 1°F, storage lives were respectively 60 and 52 days for Nagpur and Darjeeling oranges coated with wax, and 40 and 25 days for their respective controls. Hormone-treated fruits, like the controls, lost their marketable appearance through considerable desiccation, pitting, and shriveling. Loss in weight and spoilage due to fungal attack and rind blemishes were least in fruits treated with 2,4-D followed by wax coating in both varieties and each storage temperature. Pulp-to-peel ratio, reducing sugar, sucrose, total sugar, sugar-to-acid ratio, pH value, and specific gravity in juice increased, whereas vitamin C content and titratable acidity decreased, during storage in all treatments. No off flavor was produced in any case.

Notizen: A procedure developed to fractionate the major nitrogen-containing components of muscle was utilized to study the relationship of intracellular muscle proteins to tenderness. The study was performed on a group of 20 yearling bulls from two lines of cattle that had been selected for differences in tenderness. The longissimus dorsi muscle contained more total nitrogen per unit of muscle tissue and almost twice as much sarcoplasmic protein as the infra-spinatus muscle. The longissimus dorsi contained less fibrillar protein and non-protein nitrogen than the infraspinatus. The following factors were correlated with tenderness as measured by shear and panel: sarcoplasmic protein nitrogen/total fibrillar protein nitrogen; soluble fibrillar protein nitrogen/ total fibrillar protein nitrogen; water released/total water. Fibrillar protein solubility was highly correlated with tenderness (r.=−0.69 for shear and r= 0.59 for panel). An r value of 0.49, significant at the 5% level, was found between water-holding capacity and tenderness as measured by the shear.

Notizen: The major constituents of the carotenoid mixture of Italian prunes were found to be violaxanthin (35%), beta-carotene (197&b), and. lutein (16%). Less abundant constituents included cryptoxanthin, cryptoxanthiu-5,6-epoxide, cryptoxanthin 5,6,5′,6′-diepoxide, persicaxanthin, luteoxanthins, anthera-xanthin, phytoene, and phytofluene. About 20 other carotenoids were' found as very minor constituents. The earotenoid mixture in Italian prunes was notable for its low content of 5,8-epoxides.

Notizen: Six anthocyanins were isolated from Cabernet Sauvignon grapes. Four major and one minor pigment were identified by paper chromatography, color reactions, and spectroscopy. The four major anthocyanins were identified as delphinidin-3-monoglucoside, petunidin-3-monoglucoside, malvidin-3-monoglncoside, and malvidin-3-monoglueoside acetylated with chlorogenic acid. Malvidin-3-monoglucoside was the most abundant pigment of the grapes. One of the minor pigments was identified as petunidin.

Notizen: Malonaldehyde occurs mainly as the enol form (CHOH = CHCHO) in aqueous solution. The UV absorption spectrum of the compound is pH-de-pendent. Below pH 3.0, the compound is s-cis, planar, having an intramolecular H bond, with absorption maximum at 245 mμ and molar absorptivity (ε) = 1.34 × 104. Above pH 7.0, the compound is completely dissociated and the maximum absorption of the enolate anion occurs at 267 mμ with e = 3.18 × 104. The absorbance difference between acidified and basified malonaldehyde solutions at 267 mμ can be used as a measure of malonaldehyde even in the presence of other compounds that absorb in this spectral region, provided their absorption is not pH-dependent. This difference is directly proportional to malonaldehyde concentrations from 5 × 10-6M to 3 × 10-5M. The method has been successfully applied to the assay of malonaldehyde in distillates from rancid foods. Its sensitivity is only about 40% of the 2-thiobarhituric acid (TBA) test, but is sufficient to detect threshold levels of rancidity. The test is simpler, much more rapid, and more specific than the TBA test.

Notizen: Isopropyl-N-3-chlorophcnyl carbamate (CIPC) applied as emulsion dips of 0.5, 1.0, and 2.0% concentration totally inhibited wound periderm formation by potato tubers. At these concentrations, CIPC prevented growth of Fusarium sambucinum inoculates except in a few special cases. Some fungal growth occurred in puncture wounds in which trapped air at the time of dip blocked CIPC penetration prior to inoculation.Penetration of CIPC at 1.0 and 2.0% concentrations into coarse puncture wounds killed the tissues, and a rapidly spreading breakdown resembling bacterial soft rot then occurred. Smear preparations of the spoilage material revealed no microscopic evidence of microorganisms.Catechol applied by dipping in solutions of 0.1 and 0.5% had no obvious effect either on wound periderm or fungal growth. Catechol toughened exposed wound surfaces but did not appear to increase suberization deep within puncture wounds.Selected examples of within-tuber variations in wound healing and a brief survey of the histology of wound healing are also presented.

Notizen: Mycelia of three species of morel mushrooms, Morchella crassipes, M. esculenta, and M. hortensis, were grown in submerged culture in a glucose-ammonium phosphate-corn steep liquor medium. The dried mycelia were subjected to proximate analyses and amino acid determinations. A commercial morel mushroom powder was also analyzed for the same constituents. The dry samples contained 22.8–51.0% protein and 2.18–7.55% fat, depending upon the species. Amino aeid contents were similar to those reported in the literature for other fungi.

Notizen: A review has been made of published information on the phage groups and types of staphylococci concerned in food-borne intoxication. It revealed that the majority belonged to phage group III with the types 6 and 47, either alone or, with others, being the most common. In Great Britain the yearly incidence of food-borne intoxication, from 1950 to 1962, due to strains of phage group III ranged from 64.5 to 94.7%.In food handlers incriminated in outbreaks the nose was the most common focus of infection, and the hand came next.Meat and milk were the foods most commonly incriminated. Group III phages lysed 64.3% of strains found in meat and 58.1% of those in milk. Group IV phage lysed nine times as many milk-borne as meat-borne strains, which were also quite common in milk taken direct from cows, with and without mastitis or abnormal secretion.The meager data on staphylococcal contamination of “wholesome” food, meat, milk and fish, were tabulated. A high proportion of these strains were untypable, but one-fourth to one-third of the strains were lysed by phages of Group III.The results of phage typing of staphylococci from milk, dairy workers, market milk and dairy products were summarized. Phages obtained from strains of human and animal origin have been used for typing purposes. Of the phages in the “international set” obtained from staphylococci of human origin, 42D, Group IV, lysed more strains than any other phage. A set of phages of bovine origin has not yet been internationally recognized.About two-thirds of the strains obtained from bovine mastitis but three-fourths of strains front normal milk were lysed by the typing phages employed. Group III phages lysed two-and-one-half times as many strains from normal as from mastitis secretion.Cheese, butter, butter-milk, skim milk, cream, ice cream, kefir, and dried and condensed milk have yielded staphylococci lysed mainly by phages of Groups III and IV.Dairy workers, veterinary surgeons, and farmers have yielded strains similarly lysed. Some of the people in these groups as well as the animals they tended have suffered clinical disease processes, due to strains with identical phage reactions.Phage-typable strains have been found in the noses of cattle, in dogs, pigs and chickens; their human attendants have, in some cases, carried identical strains.The proportion of staphylococci, lysed by the 52/52A/80/81 complex of phages has shown a twofold increase in hospitalized human patients and a two-and-one-half increase in animals in the last few years. Staphylococci lysed by this complex are regarded as particularly invasive in and pathogenie for man.No comparison has appeared on the frequency distribution of staphylococci among the phage groups from food-borne intoxication and food handlers. A comparison was therefore made of such reported strains from: i) food causing intoxication; ii) the nose; iii) the feces; and iv) superficial lesions of apparently healthy persons. The main features were: a) the low proportion of strains lysed by phages of Group 111 in ii, iii, and iv; b) the low proportion of untypable strains, especially in i.Systematic phage typing of staphylococci from wholesome food, food incriminated in intoxication outbreaks, hospital patients and the general population in defined geographical areas is recommended. Sites such as the nose, hands, feces, and perineum of healthy people and disease processes in hospitalized patients should be searched for staphylococci, which then should be typed by the use of a standard technique with the aid of the international set of phages from strains of human origin, augmented, where necessary, by phages from strains of animal origin.In addition to the international set of “human” phages, it would be useful to establish and use an international set of phages of animal, especially bovine, origin.Phage typing cannot be used to determine whether a given staphylococcus has produced or can be induced to produce enterotoxin; but is an excellent means of assisting in determining whether staphylococci from victims of food-borne intoxication, suspected food and suspected food handlers are related.

Notizen: High inter-personal variability has been noted in the taste qualities people report for solutions of sodium benzoate. This study sought to determine whether such variability occurs with other substances and to assess the role of learning in development of the response. 24 S's replicated ratings of the intensity of sweet, salt, sour, and bitter in solutions representing 3 concentrations each of 4 familiar and 4 unfamiliar substances. Significant interpersonal variability was found for all substances. It' was lower for the familiar substances (sucrose, salt, citric acid, and caffein) than for the unfamiliar ones (sodium benzoate, monosodium glutamate, potassium chloride, ammonium chloride, and a “model” solution). Thus, learning appears to be important.

Notizen: Raw green snapbeans (Phaseolus vulgaris var. Slendergreen) were cut, frozen, lyopbilized, and extracted with chloroform-methanol 2:l. The crude extract amounted to 9.9% of the dry weight of the beans. The lipid material in the extract composed 2.6% of the dry weight of the bean. The crude lipids were fractionated with acetone, and the acetone-soluble portion was subjected to countercurrent distribution between n-heptane and 95% methanol. The major lipid fractions were treated with glacial acetic acid, followed by partition between benzene and 50% aqueous acetic acid to aid in removal of non-lipid contaminants. The composition of snapbean lipids was studied by measuring the nitrogen, phosphorus, sugar, and fatty acid content of the various fractions.

Notizen: Age-associated changes in the chemical composition of bovine biceps femoris muscle were studied. Veal muscle had significantly lower Kjeldahl nitrogen and higher moisture contents than muscle from the three older age groups studied. Muscle from veal and from the oldest group (cows, 10 years) possessed less fat than muscle from the two intermediate groups (steers, 1–2 years, and cows, 5 years). A modified procedure for determination of hydroxyproline and its use directly on mean hydrolysates are described. Use of this technique failed to reveal any significant differences in the hydroxyproline content, and presumably the connective-tissue content, of muscle from the four groups. Warner-Bratzler shear-force values of cores from biceps femoris steaks from the three oldest groups indicated that tenderness decreased with age. A method is given for isolation of large quantities of connective tissue from biceps femoris. Chemical analyses of these connective-tissue residues are presented, and the possibility is discussed that the veal connective tissue contains large amounts of reticulin.

Notizen: Both wound periderm and sprouting were completely inhibited in freshly harvested cut potatoes treated by evaporation of CIPC (isopropyl-N-3-chlorophenyl carbamate) at 10 ppm and 100 ppm (based on tuber weight) and then incubated at 70–75°F and 88% relative humidity. At 1 ppm CIPC, sprouting at room temperature was only slightly retarded. Wound periderm was completely inhibited in the central tissues and markedly retarded in the cortex of the tubers.Application of CIPC did not prevent suberization at the wound surface, but the walls of intact cells immediately subjacent were less suberized than those of the cut cells. Concomitant with inhibition of wound periderm, there was a marked enlargement of those cells that would normally have given rise to the wound periderm.Variability of wound healing rates within different tissue zones of single tubers, and other variation between tubers, are considered significant to problems of sprout control and storage.

Notizen: The development of chromophores in the glucose-glycine and sucrose-glycine systems was examined. During the reaction a number of conjugated unsaturated carbonyl compounds develop, the quality present at any one time being greater as the reaction proceeds, until browning is well advanced. During this period, which follows the period of rapid pH fall and α-amino N utilization, the fluorescence of the system increases, and the quantity of water-soluble, non-volatile compounds extraetable into various organic solvents increases. The pattern of extraction indicates the gradual formation of intermediates of greater dehydration and greater light-absorbing properties from smaller molecules. The presence of sulfites slowed the rate of development of conjugated unsaturated carbonylic and fluorescent compounds, and of subsequent early browning, whereas in the presence of sodium pyrophosphate, their rates of production are increased. Chromophores appear to develop at a faster rate in the presence of iron than in its absence, but apparently by a mechanism different from that occurring with phosphates.It is suggested that the production of larger carbonylic N-containing polymers from smaller carbonyl compounds, occurs in the sugar-amino compound systems.

Notizen: A method is described for the recovery of volatile organic components of citrus juices by a continuous, reverse-phase, liquid-liquid extraction of the juice and distillation of the extract. The distillate may be used directly for gas chromatography. Six aldehydes have been identified. Recovery of added aldebyde exceeded 90%. Assay was by a eolorimetric 2,4-dinitropbenylhydrazone method. Total carbonyl content of concentrated orange juice rose sharply shortly after processing, followed by a slower decline. The changes were qualitatively similar whether a pure aldehyde or cold-pressed orange oil was added prior to frozen storage. Carbonyls in chilled orange juice followed a roughly similar pattern, with a final rise as microbial spoilage became apparent.

Notizen: Oxidation of the sulfur amino acids by autoxidizing lipids was studied in a model system consisting of an amino acid dispersed in cold-pressed, molecularly distilled menhaden oil (20–80% w/w). Under all conditions investigated, cysteine was oxidized completely to cystine. Preliminary results suggest that at 110°C the oxidation follows first-order kinetics for at least the first 8 hr. A specific reaction rate constant of 0.25 per hour was calculated. When fatty acids were added to the system, cystine was oxidized to its thiosulfinate ester. When the fatty acid-cystine ratio was 1:2, oxidation of cystine was a maximum. No oxidation of cystine occurred unless either a fatty acid, volatile organic acid, or ethanol was added. Under the conditions investigated, methionine was not oxidized to either its sulfoxide or its sulfone.

Notizen: The acid-soluble organic phosphates of cow milk were obtained by tri-chloroacetic acid extraction or by dialysis and separated by ion exchange chromatography. Recovery in the eluate was 90–100% of the phosphates adsorbed by the resin. Approximately 90% of the phosphate fraction was sugar monophosphate. Small amounts of possible nucleotide monophosphates and of several more acidic phosphates were detected. N-Acetylglucosamine-l-phosphate, fructose-6-phosphate, galactose-l-phosphate, and glucose-6-phos-phate were identified and their quantity determined.

Notizen: Investigation of the lower-boiling fraction of orange volatiles showed the following hydrocarbons: limonene, myrcene, alpha-pinene, alpha-thujene, camphene, alpha- and gamma-terpinene, alpha-phellandrene, p-cymene, and p-isopropenyltoluene. Four sesquiterpenes were isolated from the higher-boiling fraction. The major sesquiterpene found has not been related to any known compound. Of those present in less amounts, one has been identified as farnesene, and another as ylangene.

Notizen: Optimum conditions for the reaction of food gums with the anthrone reagent vary from one gum to another. The sulfated, carboxylic acid type and mixed polysaccharides produced colors with absorption maxima at 620 mμ. The uranic acid type of polysaccharides, pectin and sodium alginate (Kelco Gel HV), produced colors exhibiting absorption maxima at 520 mμ. In all cases, color intensity increased with increasing temperature. The heating time necessary for maximum color development at 99°C varied from 4 to 10-min, depending on the hydrocolloid in question. With pectin and sodium alginate, although color intensity increased with heating time at 99°C, no definite heating time for maximum color development was observed up to 60 min. In most cases, aging led to a rapid decrease in color intensity, except for pectin and sodium alginate, in which cases color intensity increased.

Notizen: Volatile constituents of fresh butter were separated from fat and other components of high molecular weight by vacuum steam distillation. The carbonyl compounds in the aqueous distillate were converted to their 2, 4-dinitro-phenylhydrazones. Separation of these by column and paper chromatography gave the derivatives of formaldehyde, acetaldehyde, isobutyraldehyde, isovaler-aldehyde, n-hexanal, n-nonanal, phenylacetaldehyde, acetone, 2-heptanone, 2-nonanone, diacetyl and (-)-acetoin, all identified by comparison with authentic samples. Possible biosyntheses of these flavor constituents are discussed.

Notizen: Rancid lard, as determined by peroxide number, iodine number, and TBA values, inhibited the germination and/or growth of Bacillus subtilis spores. As peroxide numbers and TBA values increased and iodine numbers decreased, the number of B. subtilis spores which germinated and produced visible colonies decreased at constant incubation time. This inhibitory effect may be used as a criterion of pork fat rancidity.

Notizen: Staphylococcus enterotoxin B has been concentrated and removed from aqueous solution by froth flotation. An anionic wetting agent and an enterotoxin B antiserum labeled with Rhodamine are added to the toxin solution. Compressed air is blown through the mixture and a foam is produced. The dye-toxin complex, located in the top layer of the foam, separates from the remainder to give a distinctly red-colored fraction. With a slight increase in air pressure, the red fraction is removed. The toxin is identified by taking' one drop of the foam fraction, one drop of buffer at pH 4.5, and one drop of latex polystyrene suspension. Within 1 min a heavy agglutination occurs.

Notizen: Sugar sweetness appears to vary with hydrogen bonding. When hydroxyl groups, which elicit sweet taste, are hydrogen bonded, ability to cause sweet taste appears to be restricted. The thesis is based upon consideration of molecular models, hydrogen-bonding measurements, and taste tests. The varying sweetness of different sugars, and the apparent anomalous sweetness of sugar anomers may be largely resolved by considering hydroxyl group bonding.

Notizen: A total of 227 pork carcasses, varying in weight, chronological age, and loin intramuscular fat content, provided bellies for a study of some factors possibly associated with bacon quality. Tenderness scores of bacon significantly improved with a decrease in age and weight and with an increase in intramuscular fat content of the longissimus dorsi. The bacons derived from the 36–42-month packer carcasses were less tender than those from the other age and weight categories studied. Juiciness scores were not associated with carcass weight, age, or intramuscular fat content of the longissimus dorsi.The bellies shrank approximately 13% during the curing, smoking, and skinning processes. There were differences in shrinkage due to weight and age groups, but no significant differences in shrinkage due to intramuscular fat content of the longissimus dorsi were found.The mean value of the percentage of separable lean in bacon from the 227 carcasses was 31.7%. Average shrinkage during the cooking of the sliced bacon was approximately 66%. Lean bacon shrank significantly less than did fat bacon.About 19% of the bacons were considered to be excessively salty, and originated from carcasses possessing a more highly unsaturated fat.

Notizen: The semimembranosus, semitendinosus, and the longissimus dorsi muscles were excised from a Good-grade, and the longissimus dorsi from a Choicegrade, beef carcass, both of known history. Each muscle provided four roasts and samples adjacent to each roast for determination of total moisture in the raw meat and for tube-cooking. The meat was oven-cooked and tube-cooked to internal temperatures of 140, 158, and 176°F (rare, medium, and well-done).When the data were analyzed statistically, no difference in the distribution of fluid in longissimus dorsi was shown between Choice grade and Good grade, nor was there a demonstrable difference between left and right sides in the muscles tested.Total moisture content averaged 69.7, 64.7, and 60.3%, respectively, for 140, 158, and 176°F internal meat temperature, and mean press fluid as determined by the one-minute method, was respectively 54.0, 45.2, and 36.4%.Bound water (not released by pressing but removed by vacuum oven drying) varied little when. related to dry matter in the meat at each stage of cooking: 21–22 g for each 30 g of dry matter at 140, 158, and 176°F. Total fluid content (press fluid plus hound water) was respectively 76.0, 70.5, and 64.1%.

Notizen: Methods are presented for cooking a small sample of meat in a Pyrex tube, termed tube-cooking, and for determining press fluid in a small sample (1/2 g) of cooked beef, referred to as the 1-minute method.The 1-minute method was compared with the 15-minute method since both of these methods use the Carver Press. When the results were averaged and compared, the correlation was close. Besides being faster than the 15-minute method, the 1-minute method has the advantages that a small sample of meat is used, no grinding of the meat is necessary, and a greater percent of press fluid is obtained.

Notizen: One hundred and six samples representing 57 species and varieties of edible plants were collected (Mar. 4-Oct. 27, 1955) in Cuba. Eighty of the collections were made in the field, 19 in market places, and 7 in factories. In most instances, the food samples were trimmed to remove the portions not commonly eaten by the Cuban people. The edible portions were analyzed for content of moisture, lipid (ether extract), crude fiber, nitrogen, ash, calcium, phosphorus, iron, carotene, ascorbic acid, thiamine, riboflavin, niacin, tryptophan, lysine, and methionine. Results are expressed on the basis of grams or milligrams per 100 grams of edible portion, and are compared with data obtained from samples of similar food collected previously in Cuba.

Notizen: The effect on the nitrogen balance of young dogs of supplementing lime-treated corn with small amounts of black bean flour, skim milk, fish flour, and torula yeast was investigated. Although the diets were kept isonitrogenous, all supplements increased nitrogen retention significantly, as did supplementing with lysine and tryptophan. The gain was most marked for skim milk, fish flour, and torula yeast plus lysine, and of sufficient magnitude to be of practical significance for human feeding. The better the protein quality of the supplement, the greater the decrease in nitrogen retention after its removal.

Notizen: KF Streptococcus media were examined as to suitability for isolation and enumeration of enterocoeei from foods. Recovery of Streptococcus faecalis, Streptococcus faecalis var. zymogenes, Streptococcus faecalis var. liquefaciens, and Streptococcus durans was excellent with either a pour-plate technique or the liquid medium in an MPN technique. Streptococcus bovis, Streptococcus equinus, and Streptococcus mitis can be isolated with these media, but low recovery levels are obtained in the broth. Food constituents in concentrations as high as one part in five do not appear to affect the specificity of these media. The development of red colonies in the agar medium is indicative of the presence of S. faecalis or one of its varieties. The development of pink colonies in the medium or turbidity in the broth requires isolation and further study to determine the presence of enterocoeci.The commercially available dehydrated media appear to give excellent results, comparable to those obtained with batches compounded in the laboratory; however, there is some indication that extended storage of the dehydrated form may lead to deterioration.

Notizen: The perception of changes in the relative intensity of sweetness and acidity was investigated with series of sucrose-citric acid mixtures at near-threshold intensities—up to 2% sucrose and up to .0885% citric acid. Changes in citric acid concentration were generally perceived by some tasters to increase sweetness and by other tasters to decrease sweetness. Similarly, changes in sucrose concentration increased or decreased perceived acidity. It is suggested that contradictions between this and previous studies might be due to differences in procedure, which could affect the relative perception of taste intensities. Perceptual processes play as great a part in determining responses to very weak tastes as do the stimuli themselves. Controls and measures of tasters' prior relevant behavior are suggested to be necessary for proper interpretation of their responses.

Notizen: Definition of texture is reviewed, and a system for classification of textural characteristics of foods is described. The system is based on fundamental rheological principles, and at the same time is suitable for routine use. Textural characteristics are defined and classified into mechanical and geometrical qualities as well as those related to the moisture and fat content of a product. The mechanical characteristics are subdivided into the primary parameters of hardness, cohesiveness, viscosity, elasticity, and adhesiveness, and into the secondary parameters of brittleness, chewiness, and gumminess. It is pointed out that popular terms used to describe texture often denote degrees of intensity of these characteristics. The proposed classification lends itself to use with both objective and subjective methods of texture characterization.

Notizen: Data obtained with several banana varieties show excellent qualitative and quantitative correlations between the development of flavor and odor notes and chemical analysis for volatiles by gas-liquid chromatography. The characteristic “banana-like” flavor is due to the amyl esters of acetic, propionic, and butyric acids. The distinctive “fruity” and “estery” notes are attributed to butyl acetate, butyl butyrate, hexyl acetate, and amyl butyrate. It is evident from these studies that determination of the chemical composition of the volatiles has permitted a much more precise characterization of flavor and odor notes, and, conversely, that these flavor profiles contribute greatly to interpretation of the significance of chemical constituents. The correlations found also substantiate the potential value of gas chromatographic analysis for routine evaluation of banana fruit quality. It is anticipated that the combined use of these two techniques will enhance the value of both in their application to numerous flavor and odor problems.

Notizen: Standard rating scales of hardness, brittleness, chewiness, gumminess, viscosity, and adhesiveness were established for quantitative evaluation of food texture. The scales cover the entire intensity range found in food products and may be expanded at any desired point for greater precision in a narrower range. Each point on the scale is represented by a food product selected on the basis of availability, familiarity, constancy of textural characteristics, and other criteria. Using the developed scales, correlation was good between sensory and instrumental (texturometer and viscosimeter) evaluations of texture.

Notizen: A texture profile method was developed that uses the A. D. Little flavor profile method as a model. A texture profile is defined as the organoleptic analysis of the texture complex of a food in terms of its mechanical, geometrical, fat, and moisture characteristics, the degree of each present, and the order in which they appear from first bite through complete mastication. The texture profile analysis requires a panel of judges with prior knowledge of the texture classification system, use of standard rating scales, and proper panel procedures with regard to the mechanics of testing and sample control.

Notizen: A new recording instrument, the “texturometer,” gave good correlation between instrumental values and subjective evaluation by a trained texture profile panel. It was applied to measurement of the mechanical textural parameters: hardness, cohesiveness, viscosity, elasticity, adhesiveness, brittleness, chewiness, and gumminess. Subjective definitions of these parameters are interpreted in terms of physical measurement characterized by the texture “profile.” Examples of representative profiles are included.

Notizen: There were no significant differences in consumer preferences between different levels of salt (from 1.5 to 3%) in hams, but there was a significant difference in preference between levels of sugar. Hams having 2% sugar were preferred significantly over hams containing no sugar, 1% sugar, and 3% sugar. There were no significant preferences in the interactions between salt and sugar levels. Preferences for neither salt nor sugar were linear. It appears that the balanced lattice design is an efficient model that may be used to guide the presentation of a large number of treatments to members of large-scale consumer panels.

Notizen: Quantitative examination of chicken muscle proteins showed that protein extractability in both breast and leg muscle decreased during frozen storage because of loss of solubility of actomyosin fraction. This decrease accompanied a decrease in the sulfhydryl-group content of muscles and loss in myosin-adenosinetriphosphatase activity. The stroma-protein fraction remained unaffected, and the sarcoplasmic-protein fraction decreased only after long storage. In the non-protein-nitrogen fraction, the amount of free amino acids and other protein-breakdown products increased as a result of proteolysis. The rate of these changes depended directly on storage temperature and time. It is suggested that chicken muscles in frozen storage undergo proteolysis and that the myofibrillar-protein fraction is denatured.

Notizen: Equations have been developed for calculation of the total quantity of pigments consisting of chlorophyll a and its derivatives (chlorophyllide a, pheophytin a, and pheophorbide a) and of chlorophyll b and its derivatives (chlorophyllide b, pheophytin b, and pheophorbide b) in a mixture of these pigments in diethyl ether. Calculations are based on conversion of the chlorophylls and chlorophyllides into the pheophytins and pheophorbides, respectively, by the addition of hydrochloric acid and reading absorbances at two wavelengths. After removal of chlorophyllides a and b and pheophorbides a and b from the diethyl ether solution of the pigment mixture by 0.01N KOH, the quantity of each of the eight components listed above is estimated by indicated experimental and mathematical procedures.

Notizen: Under appropriate conditions of acid concentration, heating time and temperature of heating, the sugar alcohols react with the anthrone reagent in a quantitative manner. Suitable conditions for reproducible quantitative results are: 0.15% anthrone in concentrated sulfuric acid and a heating time of 60 min at 99°C (in a boiling-water bath). Color measurement should be made 30 minutes after cooling the reaction tubes in an ice water bath, since the intensity of the colors increased with time. Of the various sugar alcohols tested, the order of reactivity is: Glycerol 〉 sorbitol 〉 mannitol 〉 dulcitol 〉 erythri-tol 〉 arabitol 〉 ribitol 〉 xylitol. Absorption maxima occurred at 720 mμ, for mannitol, sorbitol, and dulcitol, and at 740 mμ for erythritol. Glycerol and the other sugar alcohols exhibited no sharp absorption maxima.

Notizen: Gas chromatography offers the food chemist an unparalleled technique for separation and isolation of the components of complex volatile mixtures. Unfortunately, the problem of compound identification still remains. Often, the available quantity of an isolated pure compound may not exceed one or two milligrams. Conventional organic analytical techniques are seldom adequate for identification of such small samples. An empirical examination of infrared, ultraviolet, mass, and nuclear magnetic resonance (NMR) spectra permits the solution of a gratifying number of identification problems.The application of mass spectrometry to the identification of organic compounds is discussed briefly. Two sets of spectra are translated into organic structures as examples of the methodology.

Notizen: Green vegetable tissue was analyzed for chlorophyll and chlorophyll derivatives before and after subjecting the tissue to differential blanching treatments representative of those used in commercial food processing, and to a brining treatment. The plant material studied was okra, snapbeans, turnip greens, and pickling cucumbers. Blanching at 180°F promoted the rapid formation of chlorophyllides and pheophorbides in certain tissue in addition to pheophytins, which were formed in all blanching studies.

Notizen: Data are presented on the iron contents of stem and bud end, whole and deproteinized, extracts of 41 samples of potatoes representing various degrees of discoloration. The stem end generally contained more iron than the bud end. Statistical analysis of all samples treated as one group revealed a highly significant correlation (1% level) between increasing iron content and increasing degree of after-cooking discoloration. Of the two types of iron studied, “free iron” and “protein iron,” the protein iron gave the higher degree of correlation with blackening.The highly significant correlation between iron values and degree of discoloration was lost in about half the cases when subgroups of the samples were formed according to location grown, crop year, and variety.The data revealed that the percentage of total iron associated with the protein is higher in the stem end of the potato. Also, the stem-end protein contained considerably more iron than the bud-end protein. The difference in iron content between stem-end protein and bud-end protein showed a highly significant correlation (1% level) with tendency to blacken.

Notizen: The role of enzymes as agents for the restoration of fresh food flavor in processed foods is embodied in the “flavorese” concept of Hewitt et al. (1956). The experimental validity of this concept has been tested by adding a vegetable enzyme fraction to food prepared from the same or phylogenetically related vegetable. The flavor of the enzyme-treated processed food approached that of the fresh vegetable hut was not identical with it. In general, addition of enzyme tended to over-emphasize certain notes of the natural flavor. Odor changes were more readily detected than changes in taste. Both the qualitative and quantitative aspects of the flavor changes were affected by the processing of the vegetables, by the method and source of enzyme preparation, and by the conditions under which the alterations in flavor occurred. These results are discussed in light of the enzymology underlying the flavor changes.

Notizen: Seventy-eight carcasses of pigs, 4–42 months old, provided loins of varied intramuscular fat content. Developed experimental methods indicated that the fixation time and the staining processes of the longissimus dorsi muscle were dependent upon its structure and chemical properties. With an increase in maximum muscle fiber diameter, there was a decrease in the taste-panel tenderness scores on the cooked longissimus dorsi muscles. There were no significant relations between tenderness measurements and total amount of connective tissue; however, the coarseness of the collagenic connective tissue strands was inversely related to the tenderness of the longissimus dorsi muscle.

Notizen: Phosphorylase activities were studied in relation to pre-slaughter treatment, post-mortem glycolysis, and ultimate characteristics of porcine longissimus dorsi. Total phosphorylase activity was not affected by pre-slaughter treatment and did not appear to be associated with post-mortem muscle glycolytic rate or ultimate muscle characteristics. The Hampshire muscles which had high muscle glycogen levels immediately post-mortem also possessed especially high levels of total phosphorylase; however, when all breeds were considered, the within breed correlations for these two factors were not significant (p 0.05). Insufficient knowledge exists on the relation of the time course of phosphorylase activation and glycolytic rate in post-mortem muscle. Nevertheless, extracts of porcine muscle at 10 min post-mortem generally showed the phosphorylase to be in the b form.Short-term excitement and exercise immediately prior to slaughter caused a rapid post-mortem glycolysis, indicated by a rapid pH decline and decrease of color intensity in the muscle. This rapid glycolysis resulted in muscle with inferior water-binding properties and low color and texture scores. Long- and short-term sucrose feeding elevated the glycogen level of the muscle at slaughter, which ultimately resulted in muscle that was slightly soft and pale. Fasting 70 hr prior to slaughter lowered the initial glycogen content of the muscle and also slowed pH decline and color change during post-mortem glycolysis. Correlation between pH values and the ultimate color and water-binding properties of the muscle were significant soon after death, declining thereafter.

Notizen: An oil with a characteristic strawberry aroma was obtained from the condensate from the jam-making process. Programmed-temperature capillary gasliquid chromatography (PTCGLC) showed the oil to be a very complex material of more than 150 components. A fast-scan mass spectrometer was used to analyze the material as it was eluted from the PTCGLC equipment, and some of the more volatile compounds identified are reported.

Notizen: The isolation and identification of the volatile compounds of celery are described. Non-linear temperature-programmed gas chromatography was found to give resolution superior to that of either isothermal operation or linear temperature programming. The identification of 24 compounds from celery is reported. Of the 38 compounds thus far identified from celery distillates, the following six compounds are primarily responsible for the characteristic flavor and aroma of celery: 3-isobutylidene-3a,4-dihydrophthalide; 3-isovalidene- 3a,4-dihydrophthalide; 3-isobutylidene phthalide; 3-isovalidene phthalide; cis-3-hexen-l-yl pyruvate; and diacetyl. The phthalide derivatives are also implicated in the occurrence of certain celery off-flavors reported in the literature.

Notizen: The resistances of 37 yeast cultures to 5 chemical preservatives (sorbic, benzoic, sulfurous, salicylic, and formic acids) in concentrations increased by steps were treated statistically by the method of distribution curves, plotting the surviving cultures against the concentration of each preservative. The area confined by each curve and the coordinate axes was found to be inversely proportional to the potency of each preservative. This treatment of data seems to be a new way of evaluating chemical preservatives, and possibly antibiotics.

Notizen: The alteration of growth characteristics by environmental factors, such as growth-temperature reductions and addition of chlortetraeycline to growth medium, was studied. Three bacteria that possessed different psychrophilic abilities were used as test organisms. The stresses imposed were measured by changes in growth rate, cell pigmentation, and lytic response to lysozyme. All strains grew well at 25°C, but differences began to become more pronounced at 12°C and differences were great at 4°C. Temperature fluctuations influenced subsequent growth. The effect of environmental changes on pigmentation varied with the test strain. The lytic response to lysozyme varied but was not greatly influenced by the environmental factors tested. A strain of Brevibacterium linens was found extremely resistant to lysozyme in a number of test systems.

Notizen: Microbiological examination of poultry bruises revealed that 61.0–74.2% of the tissues examined harbored both aerobic and anerobic bacteria. These organisms were found, in experimentally inflicted bruises, to increase in number at the early stages of healing (1–2 days), followed by a rapid decrease to the level of the controls within 4–6 days. Age of bruise, environmental conditions (sanitation of batteries, temperature, and moisture), severity of the bruise, and hemoglobin and its degradation'products were found to be among factors affecting the microbial content and their growth in bruised tissue.A total of 86 predominant organisms were isolated from experimentally inflicted bruises; of these, 47 were Gram-positive cocci, 19 Gram-negative rods, 11 yeasts, 7 Gram-positive rods, and 2 Gram-negative cocci. Thirty-six percent of the Gram-positive cocci were found to belong to the genus Staphylococcus. Forty-eight percent of the Staphylococcus cultures were identified as S. aureus, and the others were S. epidermis. Fecal material and poultry feed were shown to be the source of the predominant organisms.The skin of the injured tissue may be a possible portal of entry of these microorganisms. Bruising increased the permeability of the tissue as determined by dye penetration and the extent of microbial invasion.

Notizen: Bacteria occur within normal, sound fresh fruit tissues. They are mostly gram-negative motile rods, representatives of the Pseudomonadaceae and the Enterobacteriaceae. Lactic-acid-forming bacteria are found on the surface of crops. In different crops and in different varieties, bacteria may appear abundantly in one field and rarely in others. They are found more frequently in low-growing vegetables than in tree borne fruits. In cucumbers the bacteria are more often in the tissue close to the periphery and less often in the central core. In tomatoes their frequency is highest close to the stem-scar and the central core of the fruit, decreasing toward the fruit periphery.It appears that the bacteria can enter the living plant tissue by different pathways and may persist there as harmless commensals. When the vegetables are brined, the bacteria multiply in the tissue as well as in the brine. Lactobacilli penetrate gined tomatoes primarily through the stem-scar and multiply more rapidly in the fruit than in the brine. During fermentation of tomatoes and cucumbers the Enterobacteriaceae are mostly Suppressed by the lactic-acid-forming bacteria. However, if the latter are excluded by surface disinfection of the fruits, the Enterobacteria continue to multiply, causing internal bloaters, an increase in pH, and, ultimately, putrefaction.

Notizen: Occasional solid-liquid separation of soft surface-ripened cheese packed into test tubes was examined for differences between the components with regard to growth and toxin production of Clostridium botulinum. Botulinum toxin was found in three tubes showing liquid-solid separation; in each case the toxin was present in the solid but absent from the liquid cheese portion. Two mechanisms were found to be responsible for the peculiar distribution of toxin in liquid-solid separated cheese: 1) the liquid portion possessed antimicrobial activity preventing the growth of C. botulinum whereas the solid component was antimicrobially inactive; 2) the particles in the solid cheese were able to adsorb botulinum toxin, thus preventing diffusion of preformed toxin into the liquid layer. Separation into a solid and liquid layer could be achieved deliberately by increase of the moisture content of the cheese preparation, or by mixing of thoroughly ripened cheese with relatively fresh cheese. However, in these tubes the toxin—when present—was distributed in essentially equal quantities in the adjacent solid and liquid components.

Notizen: The results reported here represent a preliminary study of the action of papain on the proteins of beef skeletal muscle. Suspensions of protein preparations which had been isolated from beef semitendinosus muscle were incubated with both crystalline papain and a commercial enzyme preparation. Analyses of ultrafiltrates of the enzyme digests indicated that all of the skeletal muscle protein fractions studied were affected by papain to some extent. Under the experimental conditions employed, the intracellular proteins were affected less by the commercial “meat tenderizer” than by crystalline papain. However, the effect of the two enzyme preparations on the connective tissue fractions was comparable. Papain appeared to affect mucoprotein and collagen more than the other skeletal muscle proteins. Incubation with papain markedly lowered the viscosity of the mucoprotein preparation. Collagen suspensions were converted to thick gels by the action of papain. These observations and the results of ultrafiltrate analyses suggest that the tenderizing effect of papain may be due at least in part to the breakdown of connective tissue.

Notizen: It has been assumed that the protein-solubility test is a measure of the amount of protein denatured in situ during frozen storage of fish muscle. This study shows, however, that the quantity of protein extracted from fresh cod muscle is reduced if C18 fatty acids are added to the extracting medium. The possibility is discussed that insolubilization occurs during extraction as a result of interaction between protein and fatty acid.

Notizen: Subjecting animals to elevated environmental temperatures immediately before slaughter resulted in increased muscle temperature and a rapid rate of post-mortem glycolysis as indicated by a rapid pH decline and decreased color intensity. A high-fat high-protein low carbohydrate ration improved the water-binding, color, and texture characteristics of the muscle. The detrimental influence of sugar feeding was less marked than in previous experiments, but muscle from animals receiving the high sucrose ration had the lowest pH and (except for the heat-treated lot) the highest percent reflectance of all lots at 24 hr post-mortem. Phosphofructokinase activity was not affected by ante-mortem treatments and did not appear to be related to glycolytic rate or physical properties of the muscle at 24 hr post-mortem. The time course of rigor mortis was markedly accelerated by heat treatment.

Notizen: The carbonyl compounds of autoxidizing salmon oil were qualitatively and quantitatively analyzed at predetermined levels of oxidation. The 2-thio-barbituric acid (TBA) number, peroxide values, and total carbonyls were determined in addition to the individual volatile and Girard-T-isolable carbonyls. The C1-C12 alkanals, C4C12 alk-2-enals, and the C6-C10 alk-2,4-dienals composed the major part of the monocarbonyl fractions. The shorter-chain carbonyls were predominant, with methanal and propanal in the highest concentration. It appears that the Girard T reagent, as employed in the investigation, degrades the precursors of the volatile carbonyl fraction.The hydroperoxides were readily destroyed in unpolymerized oil by the Girard T reaction conditions, but as polymerization proceeded the yield of hydroperoxides increased and that of the Girard-isolable monocarbonyls and malonaldehyde decreased. Polymerization of the salmon oil stabilized a large portion of the measurable hydroperoxides toward the degradative effects of the Girard and TBA reactions.

Notizen: Synthetic lecithin (phosphatidyl choline) and cephalin (phosphatidyl ethanolamine) are inactive as antioxidants for menhaden oil at 50°, but when present with added ethoxyquin are very effective synergists. Phosphatidyl inositide also has no antioxidant effect but is a much weaker synergist with ethoxyquin. Purified fish “lecithin” and “cephalin” fractions and a commercial soybean phosphatide preparation act like the synthetic phospholipids. It is concluded that most of the synergistic effects may be attributed to the nitrogenons moieties of lecithin and cephalin.

Notizen: Free amino acids in four onion cultivars were studied by two-dimensional ascending paper chromatography with the following solvents: 1) phenol-water, 8:2 (v/v), 2) n-butanol-acetic acid-water, 4:1:5 (v/v) (upper layer); and 1) sec butanol–tert butanol-methylethyl ketone–water, 4:4:8:5 (v/v), 2) n-butanol–acetic acid-water, 4:1:5 (v/v) (upper layer).The amino compounds identified in the extracts were: glutathione, aspartic acid, cysteine, cystine, glutamic acid, serine, canavanine, asparagine, glycine, arginine, lysine, threonine, tyrosine, methionine sulfoxide, alanine, dihydro-alliine, S-methyl cysteine, tryptophan, methionine, valine, phenylalanine, and mixed leuycines. Suspected as present was α-L-glutamyl-S-[β-carboxy-n-propyI]-L-cysteinyl glycine.Densitometry and colorimetry were used to determine the relative approximate amounts of alanine, aspartic acid, arginine, glutamic acid, glycine, leucines, lysine, methionine sulfoxide, phenylalanine, serine, S-methyl cysteine, threonine, tyrosine, and valine. The more abundant amino acids were: arginine, glutamic acid, phenylalanine, leucines, tyrosine, lysine, and methionine sulfoxide.

Notizen: The feasibility and advantages of using a capillary chromatographic column directly with a time-of-flight mass spectrometer were demonstrated in the analysis of several flavor extracts. The high resolving power of this column proved to be indispensable in cases where chromatographic fractions previously unresolved showed similar mass spectra. Other limitations of this combined technique are covered.

Notizen: A low-temperature high-vacuum distillation technique utilizing a molecular still is described. The flavor volatiles are distilled into liquid N2 traps, transferred to a stainless-steel helical trap of special design, and then blown into a gas chromatograph. Identification of the flavor volatiles is based on relative specific retention volume and collection of the fractions for analysis by techniques such as mass spectrometry. Results are given for application of the described techniques to study of the lipid-soluble flavor volatiles of Cheddar cheese.

Notizen: The flavor of orange juices was studied objectively through analyses of recovered volatile materials. Organic extracts of freshly recovered volatiles from juices of established varieties were shown with programmed-temperature gas chromatography (PTGC) and thermal conductivity detection to contain 40–50 components. Aroma profiles of the different juices were obtained with a programmed-temperature flame ionization gas chromatograph.Comparative evaluations were conducted of the flavor and aroma patterns of three varieties of Florida oranges: Hamlin, Pineapple, and Valencia. Preliminary investigation revealed no significant qualitative differences among varieties in gross analyses obtained with thermal conductivity an the ionization detection system using PTGC. Quantitative differences appeared responsible for the flavor differences noted among varieties.Analyses showed some compositional differences among varieties in control juices, peel-oil-free juices, their respective juice essences, and peel oils. The presence of certain chemical constituents in the juice was directly related to the peel oil. No significant qualitative differences existed in similarly prepared samples from different varieties. Some specific chemical identification and the methods used are outlined.

Notizen: Concentrated poultry volatiles were prepared by distilling water from chicken and turkey, extracting volatile components from the distillate with isopentane, and concentrating the dried isopentane extract. These volatiles were investigated by gas chromatography on an apparatus equipped with thermal conductivity detectors. Essentially all volatiles were heat-produced. Cooking in air, as contrasted to cooking in nitrogen, resulted in a much larger and more complex volatile fraction. Rancid chicken yielded a greater amount of volatiles than did fresh chicken, but qualitatively they were similar. The overall yield of volatile material was greater and of a more complex nature from skin and skin fat than from lean leg and breast muscle. Chromatograms of chicken and turkey volatiles indicated differences in their composition. It was not determined, however, whether the difference in composition was responsible for the different and distinctive flavor of chicken and turkey broths determined by sensory methods. n-Hexanal and n-2,4-decadienal were identified as two of the larger volatile fractions of fresh chicken and turkey and rancid chicken. Information on the nature of chicken and turkey volatiles can also be obtained by directly sampling vapors over the product and subjecting them to dual hydrogen flame chromatography.

Notizen: Microbiological evaluation was made of three experimental fish hydrolysates (peptones) prepared in this laboratory from a fresh-water species of fish, Barbus dubious. Ten selected microbial cultures grown in an inorganic basal medium with and without yeast or meat extract and containing different concentrations of hydrolysates, showed more or less the same growth in all the hydrolysate media. Media containing the hydrolysates were sensitive to antibiotics. The hydrolysates were quite suitable as ingredients of culture media for biochemical tests like indole and methyl-red reactions. Controls were two commercial peptones, one commercial proteose-peptone, and one commercial tryptone.

Notizen: None of 13 pesticides added to grape musts had any measurable effect on fermentation, but their distribution and relative concentrations in the end-products showed wide variation. Five cholinesterase-inhibiting insecticides (demeton, malathion, parathion, Phosdrin, and Sevin) were still present in the finished wine, whereas three cholinesterase-inhibiting insecticides (ethion, Diazinon, and Trithion) and all of the chlorinated insecticides tested (DDT, chlordane, Kelthane, Tedion, and endrin) were not detected in the wines. It was definitely established, however, that all the chlorinated compounds tested were in the sediments or lees removed after fermentation. Three cholinesterase-inhibiting compounds (ethion, parathion, and Trithion) were also more concentrated in the lees than in the original musts. Diazinon was not found in any component after fermentation, probably because it is hydrolyzed in acidic solution. Chlordane, DDT, endrin, Kelthane, Tedion, ethion, malathion, parathion, and Trithion were detected in the distillates from the lees containing these compounds, chlordane being considerably more concentrated than in the original must.

Notizen: All test cultures of Pseudomonas fluorescens established growth in a basal medium (0.02% Mg SO4, 0.1% KH2PO4, and 0.5% glucose) with NH4H2PO4, NaNH4HPO4, or (NH4)2HPO4 as the sole source of nitrogen. NH4Cl2 NH4NO3, and (NH4)2SO4 supported growth of the majority of the cultures. Complex organic N substrates were readily utilized by all test cultures. Glutamic acid, leucine, and proline were satisfactory sources of both nitrogen and carbon for all test cultures. With NH4H2PO4 as the sole source of nitrogen, fructose, galactose, glucose, mannose, maltose, trehalose, starch, arabitol, erythritol, glycerol, inositol, scyllo inosose, citric acid, malie, pyruvic, caprylic or capric acid supported growth of all cultures. 1-Nonanol, 1-decanol, and 1-hendecanol were satisfactory carbon sources.

Notizen: Three vacuum-dried papaic hydrolysates (A and B, short-term hydrolysis; and C, long-term hydrolysis) of fish muscle were prepared from a fresh-water fish, Barbus dubious. They had, in order, α-amino N contents of 22.5, 28.2, and 42.5%, and sub-peptone N content of 29.3, 32.6, and 60.9% of total N. The lysine and methionine contents of the three hydrolysates were nearly the same, ranging from 8.88 to 10.53 and 3.11 to 3.50 g/16 g N, respectively, while the tryptophan contents of hydrolysates A and B (0.66 and 0.69 g/16 g N) were much less than that of hydrolysate C (1.16 g/16 g N), indicating slower release of tryptophan than of lysine and methionine during hydrolysis. The protein efficiency ratios of hydrolysates A, B, and C were 2.01, 1.87, and 2.88 at 5% level, and 2.31, 2.39, and 2.95 at 10% level of protein intake, compared with 2.92 and 3.19 for the proteins of skim-milk powder. Weight gain response by the rat repletion method, using adult rats, showed a similar trend for the nutritive value of the hydrolysates. The superior nutritive value of hydrolysate C may be due to its higher tryptophan content.

Notizen: The thermal resistance of Micrococcus radiodurans R1, a spoilage bacterium highly resistant to ionizing radiation, was characterized. A modified “thermal-death-time tube” was used, with cells uniformly suspended in a raw meat puree reconstituted from freeze-dried and powdered beef that had been screened to remove pipette-plugging fibers and irradiated to eliminate viable aerobic organisms before use. Thermal death rate, unlike the radiation death rate, seemed to approximate an exponential form, as indicated by survival curves. A D1A0= 0.75 and z= 10.65 describes the heat resistance in beef. Simple calculations suggested that if all parts of the samples of beef reached 150° F, the lower level of the “medium-done” range, a 1-min hold at that temperature should reduce viable nymbers by a factor of 10−10 and a 2-min hold should reduce numbers by a factor of 10−20.

Notizen: Biological spoilage of non-carbonated orange drink is caused mainly by yeasts that are not inhibited by preservatives at permitted levels. A stain that distinguishes living from dead yeast cells was used to develop a technique that detected yeast growth within 24–36 hr of the addition of one viable yeast cell per 190 ml of pasteurized orange drink.

Notizen: A monomolecular surface-film method was used to evaluate lipid changes in bacteria isolated from refrigerated poultry meat. Changes in cell lipids were studied as functions of reduced growth temperature and growth in the presence of low concentrations of chlortetracycline. Temperature reduction did not cause lipid changes in representative psychrophilic bacteria but did cause profound changes in a gram-positive rod having a lesser ability to grow at 4°C. Growth in the presence of CTC caused lipid increases in all strains.

Notizen: The growth of Pseudonmonas geniculata in sterile maple sap in the presence and absence of 5 ppm formaldehyde at several temperatures was investigated. At 27°C, the growth of inocula as low as 103 cells/ml was rapid, and the effect of formaldehyde, if any, was negligible. At 7°C, the temperature slowed the growth of the bacteria, particularly in cultures inoculated with 103 or 104 cells/ml. Formaldehyde further inhibited the cultures, initially causing a decrease in the number of viable organisms and lengthening the lag period before growth began again. This was particularly noticeable in the cultures with the smaller inocula.

Notizen: The starch-liquefying abilities of alpha-amylases from pancreas, cereals, fungi, and bacteria were studied by following changes in the viscosity of potato starch pregelatinized and cooled in the Amylograph under standardized conditions and acted on by the enzyme at 37°C. The optimal pH activity for starch liquefaction was 4.0 for fungal, 4.5 for cereal, 6.5 for bacterial, and 7.0 for pancreatic amylase. A comparison of liquefying action of the enzyme systems at a constant level of dextrinogenic activity showed the pancreatic enzyme most active, followed by cereal, with the fungal least active. The relative differences between the activity of the bacterial and fungal enzymes at their optimum pH's and at 37° depended on the levels of enzyme added. The thermostable bacterial amylase also exhibited high stability toward high acidity. The pattern of starch liquefaction by action of the various enzymes, and the relation between viscosity drop and enzyme activity, are discussed.

Notizen: A series of chemical and physical measurements were carried out on samples of the longissimus dorsi muscles from 10 Danish Landrace pigs. The samples were taken out immediately after sticking and held at 37°C. Estimations were made at intervals of the content of lactic acid, adenosine triphosphate, creatine phosphate, adenosine nucleotide, and inosine nucleotide, and of pH and extensibility, until rigor mortis was complete. The material could be divided, into two groups, A and B. Group A was characterized by a slow fall of pH (max. 0.65 units/hour) and by a slow decrease in extensibility (full rigor at 280 min), whereas group B showed a rapid fall of pH (max. 1.04 units/hour) and a rapid development of rigor (full at 160 min). There was a similarly clear difference between the rates of the other changes. Q10 for the rate of pH fall was 2.70 over the temperature range 36–41°C. The day after slaughter, all carcasses that gave samples of type A were of excellent quality, whereas those giving type B were more or less pale and watery. The differences between the two groups could not be explained by different handling of pigs before slaughter.

Notizen: When potatoes are stored in nitrogen at low temperatures, starch decomposition, release of starch-bound phosphorus, and accumulation of inorganic phosphorus are less than during storage in air. Although there is a complete suppression of sugar accumulation, evidence is presented that the starch removed appears as substances, probably end-products of anaerobic glycolysis, that are volatile at the temperatures used to determine percent dry weight. The decreases in starch-bound phosphorus are balanced by a corresponding increase in inorganic phosphorus in both air-stored and nitrogen-stored potatoes. The decrease in the phytic acid phosphorus in air-stored tubers can be accounted for largely as an increase in the fraction containing phosphoproteins, nucleic acids, and phospholipids, whereas the corresponding loss of phytic acid phosphorus in nitrogen-stored tubers appears largely in the fraction containing nucleotide coenzymes and hexose phosphates. The significance of these findings is discussed in terms of the requirements for high-energy phosphate derived from the respiratory process and needed for biosynthesis.

Notizen: Investigation was made of the effect of pH, enzyme concentration, cysteine, sodium chloride, and temperature on the extent of solubilization of 0.10N sodium hydroxide-soluble proteins, elastin, and collagen of biceps femoris muscle of beef by ficin and bromelain. All protein fractions of beef are solu-biked maximally at pH 7 and 80°C by both ficin and bromelain. Ficin is particularly effective in the solubilization of elastin, even at 20°C. Cysteine and sodium chloride increase the extent of solubilization, especially of collagen and elastin (sodium chloride only). The available data indicate that collagen must be denatured before ficin and bromelain can solubilize it.

Notizen: The minimization of post-mortem glycolysis by 1) subcutaneous injections of adrenaline, which eliminates muscle glycogen ante-mortem, 2) intravenous injections of sodium iodoacetate, which inhibits phosphoglyceraldehyde dehydrogenase, or 3) rapid cooking, has resulted in poultry meat that is tender without aging. Since these treatments accelerate rigor mortis, the elimination of post-mortem glycolysis eliminates the toughening associated with an acceleration of rigor mortis in normal birds.

Notizen: The table-grape variety Flame Tokay contains cyanidin-3-monoglucoside as the principal skin pigment, 82% of the total pigment, with no evidence for the presence of malvidin-3-monoglucoside. Skin pigment compositions for the Red Malaga and Emperor varieties were also determined.

Notizen: The malic acid content of pineapple fruit is quite sensitive to changes in sunlight or conditions favoring water evaporation. By contrast, citric acid is unresponsive to these factors. The inverse relation of malic acid in the fruit and evaporative forces may be related to Crassulacean acid metabolism.

Notizen: The gritty material obtained by filtering commercial maple sirup was analyzed to determine its composition and to relate its composition to the amount of sugar sand deposited to determine the factors responsible for the formation of sugar sand. The samples, taken over a two-year period, contained calcium, malic acid, and undetermined material (probably silica) as the major constituents. The calcium, malic acid, and calcium malate content gave highly significant positive correlations with the amount of sugar sand formed, whereas the percentage of undetermined material gave a negative correlation. There was also evidence that the malic acid content was more critical in the formation of sugar sand than the calcium content. Highly significant negative correlations were obtained between the percent sugar sand deposited and the iron, copper, and boron content. Further, these constituents also gave highly significant negative correlations when compared with the calcium content of the sugar sand. The presence of potassium, magnesium, and molybdenum appeared to have little effect on the formation of sugar sand. The nonvolatile organic acids present in sugar sand were determined by paper chromatography. Results showed that sugar sand contains malic, citric, succinic, fumaric, and three unidentified organic acids.

Notizen: Commercial naringin, usually obtained from grapefruit peel, was suspected to contain a flavone. A method was devised without resorting to column chromatography whereby gram quantities of the suspected flavone were obtained. The crude flavone was first purified by solvate formation. After conversion of the flavanones present to water-soluble flavans by potassium borohydride reduction, the insoluble flavone was obtained. Characterization of the flavone led to the conclusion that it was a 7-rhamnoglucoside of apigenin identical to rhoifolin.

Notizen: Extra-cellular starch is isolated from dehydrated mashed potatoes by rehydration of 0.5-g samples with 100 ml water at 150°F. The suspension is poured over a standard 150-mesh sieve, and the water containing the freed starch gel collected and filtered. Starch so collected on 7-cm hardened and extremely retentive filter paper is stained with iodine, and its reflection density (Rd) and color characteristics measured on a color-difference meter. Transmission values may also be determined. In addition, extra-cellular starch, so collected from l-g samples, may be dried and weighed. Rd values are a linear function of the amount of starch. The temperature of the sample suspension also has a linear effect on reflection density.Since added stearates do not interfere with reflection density values, the effects of added emulsifiers on iodine color of the collected starch gel are measurable by color-difference procedures. Color difference also provides a means of characterizing other starch changes, such as retrogradation, induced by processing treatments.An insignificant number of the smallest intact cells pass through the screen to be collected on the filter paper. The intact, separated cells of cooked potato range from less than 40 to nearly 400 μ in diameter. They average about 180 μ, and over 90% have diameters between 100 and 250 μ.

Notizen: Rates of autoxidation of beef and tuna oxymyoglobins have been determined at pH 5.9 with various buffer concentrations (0.1, 0.2, and 0.6M) and temperatures ranging from 0 to 40°C. The autoxidation is first-order with respect to unoxidized myoglobin under all conditions used. The rates of oxidation of tuna oxymyoglobin were independent of buffer concentration, whereas those of beef myoglobin decreased with increasing buffer concentration. Tuna oxymyoglobin was oxidized more slowly than beef at 0 to 10°C at all buffer concentrations, and at higher temperatures and low buffer concentration; at high temperatures and high buffer concentration, tuna oxymyoglobin was oxidized more rapidly than beef. Oxidation of a crude preparation of beef oxymyoglobin was slower than that of purified myoglobin.

Notizen: Rates of oxidation of solutions of highly purified and “crude” tuna and beef oxymyoglobins were measured at 0, −5, −10, −15, and −18°C. The results show that the oxidation rate decreases with lower temperatures until solutions actually solidify; at that time the autoxidation rate increases sharply. There are variations in rates of oxidation between tuna and beef myoglohins, as well as between myoglobin solutions at different buffer concentrations; however, these are secondary to the changes noted due to freezing.

Notizen: Paper electrophoretic separation of pigments in beet extracts and in intact tissue was investigated. Pigments in an extract were separated into 9 distinct bands upon electrophoresis with 0.15M pyridine-citric acid buffer, pH 4.5. A technique is presented for the re-electrophoresis of pigments in paper section of an electrophoretogram. Using a Veronal buffer (pH 8.6) during re-electro-phoresis, heterogeneity of the pigments in major red and major yellow bands was displayed. Under specific conditions, beet pigments in a thin section of tissue could be resolved by electrophoresis.

Notizen: The sounds produced by chewing foodstuffs, or by crushing them between flat surfaces, were tape recorded and analyzed as to amplitude, frequency, and duration. Preliminary data are given on chewing sound characteristics, including certain differences between foodstuffs.