[Meat quality in broilers reared in different housing systems].

Meat quality was assessed in Cobb-500 cage vs. floor-housed broilers slaughtered at 38 vs 49 days of age. Broilers (105 birds per housing system) were reared since 1 day of age in conditions of vivarium of Center for Selection and Genetics «Zagorskoye EPH¼. Fat content in breast meat was significantly higher (p<0.05) at both slaughter ages in cage-housed broilers (2.0 and 2.7% at slaughter age 38 and 49 days, respectively) compared to floor-housed (1.6 and 2.2%). Protein content in breast meat was higher in floor-caged broilers. Total collagen content in thigh meat of floor housed broilers (789.88 mg/100 g) was 1.5 fold higher compared to cage-housed (515.80 mg/100 g, p<0.05). Fatty acid profiles of meat were mostly affected by the type of meat (red vs white) and to a lesser extent by housing system and slaughter age. Water-holding capacity in red meat significantly differed between slaughter ages and between housing systems at slaughter age 38 days (р<0.05): at slaughter age 38 days water-holding capacity in red meat was 67.3 in cage-housed broilers vs. 70.1% in floor-housed; at slaughter age 49 days 74.9 vs. 76.0%, respectively. The five-point scores of sensory taste evaluation for the meat of floor-housed broilers (4.55 and 4.91 for breast meat at slaughter ages 38 and 49 days; 4.40 and 4.90 for thigh meat) were better compared to cage-housed (4.47 and 4.83 for breast meat at slaughter ages 38 and 49 days; 4.37 and 4.70 for thigh meat). The conclusion was made that meat quality estimated by a set of the relevant parameters was marginally better in floor housed broilers in compare to cage-housed.

Biocatalytic conversion of poultry processing leftovers: Optimization of hydrolytic conditions and peptide hydrolysate characterization.

Peptide hydrolysate (PH) was produced by deep controllable bioconversion of poultry processing leftovers (broiler necks), by means of a multienzyme composition, containing four commercially available enzyme preparations (Alcalase, Neutrase, Flavourzyme, Protamex). The design of multienzyme composition (MEC) was applied to yield a hydrolysate with adjusted properties, including minimized antigenicity and bitterness. The protein recovery was optimized using Box-Behnken response surface design. The individual and interactive effects of hydrolysis conditions (time, hydromodule and MEC dosage) were studied. The experimental data were analyzed by ANOVA method and a well-predictive, second order polynomial model was developed using multiple regression analysis. Optimal hydrolysis conditions were found to be: hydrolysis time 3 h, hydromodule 2.25 l/kg and dosage of MEC 0.25%. The corresponding predicted value for protein recovery was 75.34%, 2 times higher compared to traditional long-term heating hydrolysis. The PH obtained is a low allergenic product with high antioxidant capacity.