ALBERT

Notes: The objectives of the present study were to measure the sensory profile and acceptability of 8 commercial samples of mayonnaise (4 whole fat and 4 low fat) and then to apply preference mapping to address the relationship between the descriptive and acceptability data. A total of 240 consumers were recruited in 3 Argentine cities. In each city 40 young adults and 40 older adults were recruited. Samples differed in their sensory profiles and average acceptabilities. Cluster analysis of consumers showed clear segmentation in appearance, texture, flavor and overall acceptance. Sensory acceptability segmentation was far more pronounced than age or city segmentation. Extended preference mapping showed the sensory descriptors of mayonnaise which drove the acceptability of some of the consumer clusters.

Notes: : The effect of osmotic process conditions on the volatile fraction of strawberries was studied, as well as the effect of freezing and frozen storage. Osmotic treatments were carried out on strawberries in sucrose solutions up to 20 °Brix, at atmospheric pressure (OD), and by applying a vacuum pulse (PVOD). Volatile compounds of fresh, dehydrated, and frozen-stored (at –18 °C for 1 mo) samples were obtained by simultaneous distillation-extraction. Osmotic treatments caused an increase in ester concentration and, in some cases, in furaneol less marked in PVOD. Freezing implied losses in all components, although in pre-dehydrated samples the concentration of some esters (and furaneol) remained greater than in the fresh samples.

Notes: The zero erucic acid Ethiopian mustard lines developed so far are characterized by an exceptionally high linolenic acid content in the seed oil. The mutant line N2-4961, expressing low linolenic acid content in a high erucic acid background, was developed through chemical mutagenesis. The objective of this research was to study the inheritance of low linolenic acid content in this mutant. Line N2-4961 was reciprocally crossed with its parent line C-101 and the linolenic acid content of the reciprocal F1, F2 and BC1 generations was studied. No maternal, cytoplasmic or dominance effects were detected in the analysis of F1 seeds and F1 plants from reciprocal crosses. Linolenic acid content segregated in 1: 2: 1 ratios in all the F2 populations studied, suggesting monogenic inheritance. This was confirmed with the analysis of the reciprocal backcross generation. The simple inheritance of low linolenic acid content in N2-4961 will facilitate the transference of this trait to zero erucic acid lines of Ethiopian mustard.

Notes: CAS-12 is a sunflower mutant with increased levels of palmitic (C16: 0 = 30%) and oleic (C18: 1 = 55%) acids in its seed oil, hence it has a reduced linoleic acid content (C18: 2 〈 5%). This study was conducted to determine the inheritance of high C16: 0 content and its relationship with high C18: 1 content in CAS-12. Reciprocal crosses involving CAS-12, CAS-5 (high C16: 0 content), HAOL-9 (high C18: 1 content) and HA-89 (standard fatty acid profile) were made. The F1, F2 and BC1F1 generations were obtained. The genetic control of the high C16: 0 trait in CAS-12 was partially recessive and gametophytic. In all cases, this character segregated in the ratio 19: 38: 7 (low: intermediate: high C16: 0 content) in the F2 generation. These results, together with the lack of segregation for C16: 0 content in crosses between CAS-12 and CAS-5, indicated that the genetic control of the high C16: 0 trait in CAS-12 was similar to that in CAS-5 in being controlled by partially recessive alleles (p1, p2, and p3) at three loci. Crosses between HA-89 and CAS-12, and HAOL-9 and CAS-5 (segregating for C16: 0 and C18: 1) demonstrated that the high C16: 0 and the high C18: 1 traits were independently inherited. However, C18: 1 segregation in these crosses exhibited reversal of dominance. Apparently, the low C18: 1 parental lines carried modifier genes causing the deviation.

Notes: A new race F of broomrape overcomes all known resistance genes in cultivated sunflower, but recently, sources of resistance against race F have been developed. The objective of the present research was to study the inheritance of resistance to race F in crosses between 12 resistant sunflower breeding lines, derived from three different sources of resistance, and the susceptible male-sterile line P-21. Parental lines and F1, F2, F3 and BC1 generations were evaluated for broomrape resistance. Segregations in the F2 and BC1 to resistant parent approached resistant to susceptible ratios of 1: 15 and 1: 3, respectively, in most of the crosses, suggesting a double dominant epistasis. However, segregations of 3: 13 and 1: 1 for F2 and BC1, respectively, indicating a dominant-recessive epistasis, were also found. The F3 data confirmed these results. Owing to the recessive nature of this resistance, it must be incorporated into both parental lines for developing resistant hybrid cultivars.

Notes: A histopathological survey of wild and cultured shrimp from the Gulf of Mexico was carried out to determine the prevalence and severity of infectious diseases and parasites, affecting four species of penaeid shrimp (Litopenaeus setiferus, Farfantepenaeus aztecus, F. duorarum, and L. vannamei). Around 60 shrimp were obtained from each of 10 sampling stations during different months in 1999 and 2000. One station was a shrimp culture farm from Tamaulipas State, and nine were wild stations from Tamaulipas (five), Veracruz (one), and Campeche (three) States. Thirty shrimp from each station were used for histological analysis. The remaining shrimp were frozen and kept at −20 C to carry out PCR techniques to determine the presence of white spot syndrome virus (WSSV). Some in situ hybridization analyses were applied to ascertain cases of WSS viral disease. Fresh analysis was carried out in shrimp from only one station for parasite identification. The histopathological survey performed on 688 shrimp showed no evidence of viral diseases. Two shrimp from one station were histologically diagnosed as having presumptive WSSV. Tissues from the same shrimp were processed for in situ hybridization and another 20 samples from the same station were processed to run PCR techniques. In each case, the results were negative. The same PCR procedure was applied to the rest of the frozen samples and none of them showed the presence of the WSSV. No important bacterial infections were observed in any of the wild or cultured shrimp analyzed. Fresh analysis demonstrated the presence of the cestode Prochristianella hispida and the gregarines Cephalolobus penaeus and Nematopsis penaeus. Histological analysis showed that the abundance of P. hispida varied from 7 to 90%, and G1 to G4 grades of severity were observed, with G1 being the most common. Gregarines were commonly observed in the histological slides, with a prevalence varying from 3 to 56% and G1 severity in most cases. Haplosporidan infection was observed in one sample of F. duorarum, which is the first report of this parasite in this host. Two invasive epibionts, the filamentous bacteria Leucothrix sp. and the ciliate Ascophrys sp., were found in four sampled stations. The study showed that in ten stations sampled from 1999 to 2000 in the Gulf of Mexico, shrimp populations had no serious infectious diseases.

Notes: : The effects of calcium hydroxide and screw speed on expansion, pasting, crystallinity, torque, water absorption, and solubility indices upon extruded blue maize meal products were studied, using a central composite experimental design. All the characteristics measured presented a significant quadratic regression model, indicating relationship between the responses and extrusion conditions. It was found that the expansion, crystallinity, torque, water absorption, and solubility indices decreased and the Rapid Viscosity Analyzer's (RVA) pasting characteristics increased with the increase of calcium hydroxide concentrations. The Pearson correlation indicated that the responses presented strong correlation (r 〉 0.7, p 〈 0.01) between them. Extruded products with physical appearance and expansion similar to the control were found at concentrations lower than 0.1% of calcium hydroxide.

Notes: : Apricots (Prunus armeniaca L. cv Mauricio) harvested at commercial ripening stage were treated with putrescine (1 mM), then mechanically damaged with a 25 N force and stored at 10 °C for 6 d. Putrescine treatment increased fruit firmness and reduced the bruising zones caused by the mechanical damage. Putrescine-treated fruits (both damaged and nondamaged) showed different physiological behavior than controls. Color change, weight loss, ethylene emission, and respiration rate were reduced in putrescine-treated fruits. The most remarkable effect of the mechanical damage was the significant increase in spermidine concentrations found after the compression in control apricots, which could be considered as a physiological marker of mechanical damage.

Notes: : This study simulates the conditions in which Botrytis may appear in a modified atmosphere packed horticulture product, such as strawberry, so as to elaborate a predictive model that could allow us to estimate the shelf-life of a contaminated food product in such atmosphere conditions (0 to 40% CO2). The estimated shelf-lives obtained at 18 °C were 92, 164, and 236 h in storage atmospheres of 0, 10, and 20% CO2, respectively, very close to observed values; no growth was observed above 30% CO2. The elaborated predictive model allows us to: (a) control development of this fungi if the food product is maintained in an atmosphere containing more than 20% CO2 and (b) predict the time taken for potential colonies to become visible (3 mm dia) and, thus, cause immediate rejection by consumers.

Notes: : :To evaluate the relationship between the factors affecting coagulation, the hot wire method was used for direct measurements of the renneting milk process as well as a central composite design with 3 factors: rennet concentration (x1), renneting pH (x2), and temperature (x3). Second-order models for maximum voltage (Y1), time at maximum voltage (Y2), and coagulation time (Y3) were employed to generate response surface contours. Optimum conditions for cutting time were found with x1= 0.0278 R.U./mL milk, x2= 6.60, and x3= 35 °C, for which the responses were Y1= 2854 ± 171 μV, Y2, = 14.08 ± 3.04 min, and Y3= 7.16 ± 1.12 min. No significant differences (p 〉 0.01) were found between the 3 responses obtained in the experiment and the ones predicted by the models. The use of the objective and non-destructive monitoring of curd formation and the response surface methodology can be recommended to optimize milk coagulation.