不同菌种发酵对藜麦蛋白质特性及脂质构成的影响

Effects of Different Strain Fermentation on Protein Hydrolysis and Lipid Profile of Quinoa

[目的]比较不同菌种发酵对藜麦蛋白质水解及脂质变化的影响,为藜麦发酵食品的开发提供理论参考.[方法]以藜麦为原料,加入不同菌种(酵母菌、植物乳杆菌及其混合菌)进行发酵,通过测定蛋白水解指数、蛋白质各组分、游离氨基酸、游离脂肪酸及脂质构成来判定发酵效果,确认哪种微生物更有利于藜麦营养成分的转化.[结果]经酵母、植物乳杆菌、酵母和植物乳杆菌混合菌发酵后,藜麦蛋白质水解指数均有所升高,且主要是清蛋白和球蛋白发生了水解.发酵后藜麦中的游离氨基酸含量增加显著,尤其是必需氨基酸.酵母发酵藜麦更有利于蛋白质、多肽等水解成氨基酸.通过发酵处理,藜麦中的游离脂肪酸含量显著增加,且饱和脂肪酸、单不饱和脂肪酸、多不饱和脂肪酸的比例更为接近1﹕1﹕1;甘油三酯、甘油二酯含量降低,但磷脂等功能脂的含量有所提高,且有酵母菌参与更有利于上述转化.[结论]酵母菌、植物乳杆菌发酵过程中主要水解藜麦清蛋白和球蛋白成氨基酸等小分子化合物,且游离必需氨基酸含量显著升高;两种菌发酵后都有利于增加游离脂肪酸含量,降低甘油三酯、甘油二酯含量,且提高磷脂的含量.经酵母发酵,更有利于改善藜麦营养.

【Objective】This study was performed to compare the differences of the protein hydrolysis and lipid productions during the quinoa fermentation with the different strains,so as to promote the development of quinoa added-value food by the fermentation.【Method】Yeast,lactobacillus plantarum and the two mixed was used for the fermentation of quinoa,respectively.Proteolysis index,protein composition,lipid profile,the content of total free amino acid and free fatty acid were determined to evaluate which microbe had more advantages in the transformation of nutrients.【Result】The proteolysis index increased after the quinoa fermentation by different microbes,and albumin and globulin were mainly hydrolyzed among quinoa protein composition.There was a significant increase in the free amino acid of quinoa after fermentation,especially essential amino acids.The yeast-fermented quinoa was beneficial in gaining smaller molecular compounds that originated from protein hydrolysis.The free fatty acids content increased sharply after fermentation and met a proper ratio of SFA﹕MUFA﹕PUFA close to 1﹕1﹕1.The content of triglycerides and diglycerides were reduced,but the content of functional lipids(phospholipid)was increased.The quinoa with yeast fermentation was more favorable for the above transformation.【Conclusion】Quinoa fermented by yeast or lactobacillus plantarum could result in the hydrolysis of albumin and globulin into amino acids,especially the free essential amino acid levels increased significantly.The free fatty acids also increased after fermentation,wherein the triglyceride and diacylglycerol were reduced,and the content of phospholipid was improved.Quinoa with yeast fermentation had great potential in developing high-value nutritional products in the future.