Effect of hop β-acids as dietary supplement for broiler chickens on meat composition and redox stability

Addition of beta-acids extracted from hop at different levels (0, 30 mg kg(-1), 60 mg kg(-1), 240 mg kg(-1)) to the diet of broiler chickens demonstrated significant effects on the average concentration of polar metabolites and fatty acids of relevance for meat quality. The largest metabolic differences between control group and chicken fed different levels of beta-acids were achieved using 30 mg kg(-1) of supplement. As determined by EPR spin-trapping, increased redox stability was also obtained for meat from chicken fed 30 mg kg(-1) of beta-acids which also had highest level of endogenous antioxidants, especially anserine, carnosine, NADH and PUFAs. Diet and storage period were found to affect protein oxidation and myosin and actin were recognized as the main targets of protein oxidation. Myofibrillar proteins from chicken fed hop beta-acids showed to be less susceptible to oxidation. A moderated level of hop beta-acids as dietary supplement accordingly improve the overall redox stability, protecting myofibrillar proteins and fatty acids against oxidation and improve the nutritional properties of meat from broiler chickens.