Antioxidant Activity Of Carnosine And Application Research In Meat Cold Storage

Lipid peroxidation of meat will lead to great changes in favor and color and put down nutrition value,and even produce deleterious matters. so it is very important that antioxidants is added to meat during storage to inhibit lipid peroxidation.Carnosine (β-alanyl and L-histidine) is a naturally depeptide that was found in skeletal muscle.Carnosine has been shown as a antioxidant in animal body.The anoxidant effects of carnosine were studied in three parts in this paper:anoxidant effects of carnosine in vitro;anoxidant effects of carnosine in vivo;anoxidant effects primary research of carnosine during meat storage at 4℃.Two systems were established about antioxidant experiment of carnosine in vitro:phosphatidylcholine(PC) liposomes system and pork homogenate system.In PC liposomes system,AAPH (water-soluble radicals initiator) and ·OH radicals were used to make PC liposomes peroxidate and the peroxidation was observed by TBA reaction.we added different concentrations of carnosine to the system to inhibit peroxidation.The results indicated that in AAPH-dependent PC liposomes peroxidation system,2mmol/L carnosine inhibited significantly TBARS formation in liposomes and the inhibition rate of oxidation was 9.93%;in ·OH-dependent PC liposomes peroxidation system,the inhibition rate of carnosine is a dose depended manner.5mmol/L carnosine has a significant inhibitory effect on TBARS formation of liposomes,the inhibition rate was 21.21%;The antioxidant effect of carnosine was affected notably by pH value of reaction system,at pH7.0,the inhibition rate was the greatest in ·OH-dependent PC liposomes peroxidation system.In this experiment,pork homogenates was used as a series of lipid oxidization systems caused by ·OH or metal ions to check antioxidation effects of carnosine by meams of TBA reaction.The results illustrated: in the OH induced oxidization system,1mmol/L carnosine significantly inhibited TBARS in pork homogenate (P<0.05),and the inhibition rate(IR)(%) was 13.47%,20mmol/L carnosine got a more significant effect (P<0.01),and the inhibition rate(IR)(%) was 47.90%;In the metal ions catalyzed oxidization system, inhibitory effect of carnosine on different metal ions was different:canosine had the most significant antioxidation ability in the Cu²⁺-catalyzed system,but the change range of inhibition rate in Cu²⁺-catalyzed system was not as much as in the Fe²⁺ or Fe³⁺...