牛肉低温蒸煮过程中挥发性风味成分及其前体物动态变化

Dynamic changes of volatile flavor components and their precursors during low temperature cooking of beef

目的:探究牛肉低温蒸煮过程中挥发性风味成分及其前体物动态变化情况。方法:以中心温度98℃的牛肉为对照组,分别测定中心温度60,65,70,75,80℃的牛肉中核苷酸、游离氨基酸、游离脂肪酸、总糖和挥发性风味成分,并进行感官评价。结果:低温组中鲜味核苷酸含量、等效鲜味浓度及味觉活性值显著高于对照组(P<0.05),且牛肉中心温度为65℃时肌苷酸含量最高;牛肉中心温度为60℃时,游离氨基酸总量高达739.01 mg/100 g;中心温度为65℃的牛肉游离脂肪酸含量显著高于其他温度组(P<0.05);总糖含量随牛肉中心温度的升高而降低;醛类物质在牛肉中心温度为65~75℃时大量出现,且通过计算主效风味成分的气味活度值(ROAV),发现己醛、壬醛、庚醛、辛醛、苯甲醛、乙酸乙酯、蒎烯及对-二甲苯是低温蒸煮牛肉的关键挥发性风味物质(ROAV≥1);感官评价显示中心温度为70℃的牛肉综合评分最高,牛肉香味浓郁。结论:牛肉中心温度为65~75℃时,食用性及风味品质更佳。

Objective:In order to explore the dynamic changes of volatile flavor components and their precursors during low temperature cooking of beef.Methods:Beef with central temperature of 98℃was used as control group.Nucleotides,free amino acids,free fatty acids,total sugars and volatile flavor components in beef with central temperature of 60,65,70,75 and 80℃were determined,and sensory evaluation was carried out.Results:The results showed that the content of fresh flavor nucleotides,equivalent fresh flavor concentration and taste activity in the low temperature group were significantly higher than those in the control group(P<0.05),and the inosinic acid content was the highest when the central temperature of beef was 65℃.The total amount of free amino acids was as high as 739.01 mg/100 g,and the content of free fatty acids in beef with central temperature 65℃was significantly higher than that in other temperature groups(P<0.05).The total sugar content decreased with the increase of beef central temperature,and aldehydes appeared in large quantities when the beef central temperature was 65~75℃.By calculating the odor activity values of the main flavor components,it was found that hexanal,nonanal,heptanal,octanal,benzaldehyde,ethyl acetate,pinene and p-xylene were the key volatile flavor compounds(ROAV≥1).Sensory evaluation showed that the beef with a central temperature of 70℃had the highest comprehensive score and rich flavor.Conclusion:The above indexes fully show that the edible and flavor quality of beef is better when the central temperature is 65~75℃.