羊肉冷藏期间蛋白与脂质氧化及风味变化分析

为探究冷藏过程中羊肉蛋白与脂质氧化及风味物质的变化规律，于温度4 ℃，相对湿度48%条件下贮藏羊肉，采用市售普通PE保鲜膜进行包装，测定不同冷藏时间羊肉的硫代巴比妥酸（TBARS）值、巯基值和挥发性风味物质的变化情况。结果表明:随着贮藏时间的延长，TBARS值呈先上升后下降再上升的趋势；巯基值贮藏前4 d呈下降趋势，从第5 d开始增长。从冷藏羊肉中检测出9大类挥发性物质，共31种化合物，具有樟脑气味的叔丁醇含量随贮藏时间的延长逐渐降低，庚醛、正辛醛、正己醛等羊肉的主要香味物质第3 d时含量最高，贮藏至第5 d时检测出3-羟基-2-丁酮和2-庚酮，第7 d检测出引起酸败腐臭味的异戊醛及二甲基二硫。综上所述，在冷藏条件下，第3 d羊肉的风味品质较好，第5 d可能为羊肉变质的转折点。

Analysis of Change of Protein and Lipid Oxidation and Flavor in Mutton during Refrigeration Storage

In order to investigate the changes of protein and lipid oxidation and flavor substances of mutton during cold storage, mutton was stored at 4 ℃ and relative humidity 48%, and packaged with ordinary PE plastic wrap, determination of different cold storage time of mutton thiobarbituric acid reactive substances (TBARS) value, sulfhydryl content and the change of volatile flavoring substances. Results showed that during refrigeration storage, the value of TBARS increased first, then decreased and then increased. The sulfhydryl value decreased on the four days ago and increased from the 5th day. Nine kinds of volatile components were detected from the refrigeration mutton, a total of 31 kinds of volatile compounds, the content of 1-butanolwith a smell of camphor was reduced with the storage time. The main flavoring substances of heptanal, octanal and hexanal were the highest levels on the third day, the 3-hydroxy-2-butanone and 2-heptanone were detected on the 5th day. 3-methylbutanal and dimethyl disulfide were detected which caused sour and rancid smell, on the 7th day. In conclusion, the flavor quality of mutton on the 3th day is better under refrigeration storage conditions, and the turning point of mutton deterioration may be on the 5th day.