Analysis of qualitative and nutritional value of broiler chickens breast muscles, when their diet supplemented with betaine

Abstract

The aim of this work - to do qualitative and nutritional analysis of broiler chickens breast muscles, when their diet supplemented with betaine. The purposes of this study were to investigate the effects of betaine on broiler chickens breast muscles physico-chemical and histomorphometric properties, composition of fatty and amino acids, formation of malondialdehyde (MDA) and biogenic amines, alterations of sensory and texture properties. The feeding test was performed with 1000 broiler chickens line combination ROSS 308, which were divided into 4 groups (control and I, II, II experimental). Birds in control group were fed with standard feed, experimental group’s feeds were supplemented with 1 kg (I experimental), 2 kg (II experimental) and 3 kg (III experimental) betaine additive. At the end of feeding test, 5 chickens were selected from each group and slaughtered in accordance with the laws of the Republic of Lithuania, European Union (EU) directives and European Commission (EC) recommendations. After slaughter, broiler chickens breast muscles quality, sensory and texture properties were determined. The results showed that the betaine additive in feed had a positive effect on broiler chickens breast muscles quality: compared to the control group cross-sectional area of fibers were 16.56 and 11.35 % larger (p<0.05) in I and II experimental groups, respectively, and greater amount of PUFA were identified in III experimental group. Betaine additive affected broiler chickens breast muscles oxidation processes: compared to the control group MDA concentrations in II and III experimental groups were 32.94 and 48.24 % lower (p<0.05; p<0.01), respectively. After storage, MDA concentrations were 56.16; 45.32 and 59.61 % lower (p<0,001), respectively, in I, II and III experimental groups. The resulting norms of biogenic amines were not exceeded. The analysis of the sensory properties of the samples did not reveal any significant differences between evaluated properties, except for meat juiciness, the average of which in I experimental group was 7.50 points (p<0.05). Betaine additive affected texture properties of the breast muscles: samples of II experimental group had biggest cohesion force (0.87 kN (p<0.05)), as well II experimental groups samples were 6.53 kN tighter (p<0.05) than III experimental groups samples, the biggest springiness obtained in I experimental group samples, the differences were 0.14; 0.20 and 0.60 kN (p<0.05), respectively, comparing to control, II and III experimental groups. The highest total amino acid content was found in the control group (754.20 g/kg SM), where the amount of methionine was 3.44 g/kg SM higher (p<0.001) compared to I experimental group. The effect of betaine additive on the physico-chemical properties has not been established