混合乳酸菌发酵改善罗非鱼蛋白酶解液风味的研究

通过嗜热乳链球菌（Streptococus thermophilus）和保加利亚乳杆菌（Lactococcus bulgarcus）混合发酵，改善罗非鱼（Oreochromis niloticus）下脚料蛋白酶解液风味，采用响应面设计试验考察乳酸菌发酵时间（X1）、温度（五）及接种量（恐）对酶解液风味感官评分值（Y）的影响，并利用同时蒸馏萃取与气相色谱-质谱（GC—MS）联用技术测定挥发性成分。结果表明，响应面分析法（RSM）优化的乳酸菌发酵条件为时间9h，温度45℃，接种量16％，预测风味感官评分值为4．1；酶解液发酵后的挥发性成分由原来的27种增加至33种，增加的主要是酯类物质，另外产生了辛酸及十六醛等风味物质。乳酸菌发酵能减弱罗非鱼酶解液的腥味，但脱苦效果不明显。

Flavour improvement of hydrolysate from tilapia (Oreochromis niloticus) with lactic acid bacteria fermentation

The flavour of hydrolysate from Oreochromis niloticus was improved with mixed lactic acid bacteria fermentation of Streptococus thermophilus and Lactococcus bulgaricus. Response surface methodology was used to study the effects of fermentation time （X1）, fermentation temperature （X2 ） and inoculation volume （X3 ） on the sensory scores of hydrolysate flavour. The volatile components of hydrolysate were evaluated by simultaneous distillation-extraction （SDE） and gas chromatography-mass spectrometry （GC-MS）. The results indicated that the optimal conditions of fermentation were X1 = 9 h, X2 = 45℃ and X3 = 16%. The predieted value of response optimal conditions was Y = 4. 1. After fermentation, the number of volatile components of hydrolysate increased from 27 to 33, which were mainly ester. Besides, other flavour compounds such as caprylic acid and palmitic aldehyde were also produced. The lactic acid bacteria fermentation could remove fish odonr of protein hydrolyzates but its debittering effect was not obvious.