Viscoelasticity of frozen/thawed egg yolk

Dynamic rheological measurements indicate that the gel formed during freezing is based on physical aggregation rather than chemical binding, with a nonhomogeneous structure. The gelation was highly dependent on frozen storage temperature in the range -10 to -14 degrees C, but there was no appreciable difference in the range -14 to -24 degrees C. When yolk was maintained motionless and supercooled at -10 degrees C and -12 degrees C for 23 hr, no change in the complex modulus, G*, was observed, but there was a considerable increase when yolk was disturbed and became frozen at the same temperatures for the same time.

Density, heat capacity and thermal conductivity of liquid egg products

Density, heat capacity and thermal conductivity of liquid egg products, such as egg white, egg yolk, whole egg and various white and yolk blends, were determined as affected by temperature and water content ranging from 273 to 311 K and 51.8 to 88.2% (mass), respectively. Polynomial models fitted the experimental data very well, showing a linear relationship both for temperature and water content. (c) 2005 Published by Elsevier Ltd.

Rhodocyclus gelatinosus biomass for egg yolk pigmentation

Biomass of the photosynthetic bacterium Rhodocyclus gelatinosus was used at different levels in laying hens' rations as a xanthophyll source. Sixty-four hens were used in the experiment that investigated the effects of different biomass concentrations on weight gain, egg production, egg weight, and yolk color as compared with a control group that received no biomass supplementation in the ration. Yolk color was scored by means of a color fan. All concentrations tested were able to provide yolk color scores higher than those provided by the control group. The pigment deposition began after 24 h of administration and reached a plateau around the twentieth day. Each increase in the supplementation level led to an additional increase on yolk color scores. Yolk colors of all treatments that received R. gelatinosus biomass differed significantly from the control group and from each other, corroborating that the increase in the biomass supplementation had a positive effect on color increase. Body weight loss occurred in all treatments. Egg production did not increase with the biomass addition, while a significant increase in egg weight was observed in the treatments that received the product.

Viscoelasticity of frozen/thawed egg yolk as affected by salts, sucrose and glycerol

Based on dynamic rheological measurements, sucrose, glycerol and magnesium chloride (MgCl2) prevented egg yolk gelation at concentrations of 2% and higher, These additives showed improved cryoprotectant effects as their concentrations were increased, Sodium chloride (NaCl) at higher than 2% also prevented gelation but at 10%, it caused a considerable increase in viscosity of unfrozen yolk, Calcium chloride (CaCl2) showed an opposite effect, promoting protein coagulation before freezing, Samples with 2% CaCl2 gelled completely after 36h at -24 degrees C, Before freezing, potassium chloride (KCl) in the range 2-10% had an effect similar to that of NaCl, However, after freezing its effect changed, Yolk with 2% KCl, frozen 36h at -24 degrees C, showed very elastic behavior.

Estimates of genetic parameters, and cluster and principal components analyses of breeding values related to egg production traits in a White Leghorn population

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Utilisation of bacterial (Rubrivivax gelatinosus) biomass for egg yolk pigmentation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Gut intraepithelial lymphocyte counts in neonates, infants and children

Intraepithelial lymphocyte (IEL) counts were histologically assessed in the jejunum, ileum and appendix of 39 neonates (0-28 days), 32 infants (1-9 months) and 13 children (1-9 years). Small intestinal mucosa samples were obtained from 73 autopsies, and from 8 surgical and 3 aspirative biopsies. IEL counts of specimens from the jejunum, ileum and appendix gave similar results in the same patient. The number of IEL counts was significantly lower in neonates for all three segments. The difference between infants and children was more marked in the jejunum than in the ileum, although this was not significant. In the appendix, there was no difference between the different age groups. Our results indicate that postnatal expansion of IEL occurs homogeneously along the gut after the neonatal period.

Factors affecting somatic cell counts and their relations with milk and milk constituent yield in buffaloes

Data concerning daily milk yield (MY), percentage of milk fat (%F), protein (%P), lactose (%LT), and total solids (%TS), and somatic cell counts (SCC) for a herd of 222 Murrah buffalo reared in the state of São Paulo, Brazil, were collected monthly from 1997 to 2000 in order to study the factors affecting SCC and their relation to milk production and constituents during lactation. SCC decreased in the second month of lactation and increased thereafter, up to the ninth month of lactation. The interaction of month of lactation x order of calving was significant. Mean MY observed during the first month of lactation was 6.87 kg, which increased to 7.65 kg during the second month, and then decreased until the ninth month of lactation (3.83 kg). During the different months of lactation, %F, %P, %LT, and %TS ranged from 6.28 to 8.38%, 4.05 to 4.59%, 4.96 to 5.34%, and 16.94 to 18.55%, respectively. Calving year, calving order, and order of month of lactation significantly affected MY, %F, %P, %LT, and %TS. The regression coefficients of transformed SCC on MY and %LT were negative and significant during all months of lactation, showing that milk and lactose yield decreased with increased transformed SCC, causing losses to buffalo milk producers.