猪皮毛霉固态发酵过程中营养及挥发性风味的动态变化

Dynamic changes of nutrients and volatiles of pigskin during solid-state fermentation by Mucor sp.

该文研究了毛霉固态发酵猪皮过程中其微观结构、相关酶活力、主要营养成分以及挥发性风味物质的动态变化,为微生物发酵猪皮的高值化利用提供理论依据。研究以总状毛霉XH-22为菌种对猪皮进行固态发酵,分别于发酵0~7 d取样测定游离氨基酸、多肽、可溶性蛋白的含量和蛋白酶活力,并采用气质联用法测定发酵过程中挥发性风味物质的变化。结果表明,与未发酵的猪皮相比,经毛霉固态发酵后0~6 d猪皮的游离氨基酸总量随发酵时间延长而增加,7 d略微下降,下降不显著(P>0.05),游离氨基酸总量提高了22.6%;多肽含量随发酵时间延长而增加,增加了2.6倍;可溶性蛋白含量、蛋白酶活力呈先上升后下降趋势,并于发酵5 d时达到最大值;发酵7 d时挥发性风味物质增加了12种,醇、醛、酯类物质显著增多,酮类含量显著增加(P<0.05)。因此,毛霉固态发酵能提高猪皮的营养价值,改良猪皮风味,可为开发相关功能性产品提供新的途径。

To study the dynamic changes of microstructure,related enzyme activities,main nutrients,and volatiles of pigskin during solid-state fermentation by Mucor sp.,and provide a theoretical basis for the high-value utilization of microbial fermentation of pigskin,Mucor racemosus XH-22 was used to carry out solid-state fermentation of pigskin,and samples were taken at 0-7 days of fermentation to determine the content of free amino acids,peptides,soluble proteins and protease activity.Moreover,gas chromatography-mass spectrometry was used to determine the change of volatile flavor compounds during the fermentation.The results showed that compared with unfermented pigskin,the total free amino acids in pigskins increased with the fermentation time for 0-6 days after solid-state fermentation by M.racemosus,and decreased slightly at 7 days(P>0.05),and the content increased by 22.6%.The content of peptides increased with the extension of fermentation time,which increased by 2.6 times;the soluble protein content and protease activity showed a trend of increasing first and then decreasing,and reached the maximum at 5 days of fermentation;12 kinds of volatile flavor substances increased after 7 days of fermentation,types of alcohol,aldehyde,ester substances and ketone content increased significantly(P<0.05).Therefore,solid-state fermentation of M.racemosus can increase the nutritional value of pigskin and improve the flavor of pigskin,which can provide a new way for the development of related functional products.