微生物发酵与酶法结合制备天然奶味香基的研究

选用具有丁二酮合成能力的乳酸乳球菌NRRL B-2356发酵全脂乳与脂肪酶结合制备天然奶味香基。乳酸乳球菌NRRL B-2356发酵全脂乳丁二酮、3-羟基丁酮产量在27h时达最大(52.95μg/mL),与德氏乳杆菌混合发酵,两者接种量比值为5:1时,丁二酮、3-羟基丁酮含量达60.1μg/mL,香气评分最高。利用脂肪酶palatase2000L对发酵液进行酶解修饰以提高香气强度,酸值为6.73mgKOH/g时香气评分最高。同时蒸馏萃取装置与GC-MS结合对奶味香基中挥发性成分进行了分析,结果表明,游离脂肪酸为98.586%,酮类1.219%,内酯类0.142%。研究制备的奶味香基香气纯正浓郁,可用于调配高档奶味香精。

The Research of Nature Milk Base Flavor by Combining Fermentation with Lipolysis

Lactococcus lactis subsp.lactis NRRL B-2356 which was capable of forming diacetyl was chosen and combined with lipase to prepare natural milk base flavor.The amount of diacetyl and acetoin reached maximum(52.95μg/mL) when Lactococcus lactis subsp.lactis NRRL B-2356 has been fermented for 27h alone.The aroma was rated the highest when Lactococcus lactis subsp.lactis NRRL B-2356 was mixed with a lactobacillus delbruekii having an inoculation ratio of 5 to 1 and the amount of diaceytl and acetoin was 60.1μg/mL.Palatase 20000L was chosen to modify the aroma of the milk base flavor and the aroma was rated the highest when acid value of the base was 6.73mgKOH/g.The volatile compositions of the milk base flavor were estimated by combining SDE with GC-MS and the results showed:free fatty acids was 98.586%,ketone was 1.219%,lactone was 0.142%.The milk base has a natural full-bodied milk flavor and could be used to prepare top milk essence.