蒙古族木桶发酵奶酪成熟阶段风味变化研究

Impact of different ripening times on mongolian barrel-fermented cheese flavor

选择成熟期为0、10、20、30 d的木桶发酵奶酪,对其成熟过程中游离氨基酸、基本化学成分、挥发性风味物质构成进行差异性分析研究。结果表明,成熟达到20 d时游离氨基酸Asp、Leu、Glu和Pro呈显著增加(P<0.05),在成熟期达到20~30 d时游离氨基酸含量呈上升趋势。且在此阶段蛋白质、脂肪和pH值变化存在显著差异。水分则在0 d时差异显著。其中水分含量与风味物质(9-癸烯酸、月桂酸、3-甲基-1-丁醇、正己酸乙酯、反油酸乙酯、甲基壬基甲酮、4-甲基苯酚)呈显著正相关(P<0.05)。蛋白质、脂肪和风味物质(正己酸、辛酸、肉豆蔻油酸、丁酸、正癸酸、乳酸、异戊酸和壬酸乙酯)呈显著正相关(P<0.05)。pH值与正己酸呈正相关(P<0.05)。在不同成熟阶段木桶发酵奶酪中共检测出56种风味物质。当0 d时,产品生成较多的酸类、醇类和少量酯类、酮类及其它物质,此时风味较好。当成熟到第10 d时,大量的脂类物质生成。20 d时酸类、醇类、酯类和酮类物质大量产生,此时奶酪风味达到最佳。成熟30 d时挥发性成分分布没有显著差异,并且随着水分的大量减少,风味物质含量不断下降。

Barrel-fermented cheeses with ripening periods of 0 d,10 d,20 d,and 30 d were selected for analysis of the composition of free amino acids,essential components,and volatile flavor substances during cheese ripening.The results showed that the free amino acids Asp、Leu,Glu and Pro(P<0.05)increased significantly at 20 d of ripening.Significant differences in protein,fat and pH changes were observed at 20-30 d of ripening.Water content differed significantly at 0 d.Moisture content was significantly and positively correlated(P<0.05)with flavor substances(9-decenoic acid,lauric acid,3-methyl-1-butanol,ethyl hexanoate,ethyl transoleate,methyl nonyl ketone,and 4-methylphenol).Protein,fat and flavor substances(nhexanoic acid,octanoic acid,myristic oleic acid,butanoic acid,n-decanoic acid,lactic acid,isovaleric acid and ethyl nonanoate)were significantly positively correlated(P<0.05).pH was positively correlated with n-hexanoic acid(P<0.05).A total of 56 flavor substances were detected in barrel cheese at different ripening times.At 0 d,more acids,alcohols and small amounts of esters,ketones and other substances were produced,and the flavor was better at this time.By the 10th day of ripening,a large number of lipids were produced and by the 20 d,a large number of acids,alcohols,esters and ketones were produced and the cheese had the best flavor.There was no significant difference in the distribution of volatile components at 30 d of ripening.The content of volatile flavor substances decreased continuously with the significant reduction of water.