米曲霉发酵罗非鱼及产物挥发性成分分析

采用米曲霉发酵罗非鱼制备腊鱼风味的咸味香精基料,初步确定发酵工艺如下:温度为37℃,接种量(米曲霉单位数/鱼肉重)为4×108cfu/g,料液比(鱼肉重/水重)为0.2(w/w),发酵时间为40h,产品具有明显腊鱼香味,无明显腥臭味,香气浓烈持久;采用聚二甲基硅氧烷/二乙烯基苯型涂层纤维萃取头(PDMS/DVB),通过固相微萃取和气质联用技术(SPME-GC-MS)分析鉴定发酵前后挥发性成分,分别鉴定出53种和75种化合物,其中发酵后产品中的醛类和醇类相对含量较高,检测到较高含量的壬醛、正己醛、辛醇、3-羟基丁酮、2-十一酮、1-辛烯-3-醇,其中壬醛、己醛和辛醇均具有特殊的脂肪气息,1-辛烯-3-醇具有明显的蘑菇和泥土味,2-十一酮具有典型牛奶香气。

Tilapia fermented by Aspergillus oryzae and analysis of its volatile compounds

Aspergillus oryzae was applied to ferment semi-dried smashed Tilapia meat to synthesize a special salted fish flavor base,which was confirmed to be essence with strong and long-lasting meat and sauce flavor,the fermentation conditions were controlled as follows:temperature:37℃,inoculation amount:4×108cfu/g,mass ratio of fish to water:0.2(w/w),fermentation time 40h.Solid phase micro-extraction equipped with PDMS/DVB and gas chromatography-mass spectrometry(GC-MS)was performed to identify volatile compounds of fermented and unfermented tilapia,the results showed that 53 and 75 kinds of compounds were found respectively,aldehydes and alcohols had the highest amount,nonanal,hexanal,octanal,1-octen-3-ol,n-caproic acid vinyl ester were typical volatile compounds of fermented tilapia,nonanal,hexanal and octanal were typical fat flavor substances,1-octen-3-ol was of typical mushroom and soil flavor,2-undecanone was of typical milk flavor.