乳酸菌发酵改善小麦胚芽的营养品质与贮藏特性的研究

Improvement of Nutritional Qualities and Storage Characteristics of Wheat Germ by Lactic acid bacteria Fermentation

摘要:

利用植物乳杆菌（Lactobacillus plantarum dy-1）发酵小麦胚芽，研究其发酵前后营养品质与贮藏特性的变化。结果表明，Lactobacillus plantarum dy-1中存在谷氨酸脱羧酶（GAD），能够转化L-谷氨酸生成γ-氨基丁酸（GABA）；发酵后的小麦胚芽总游离氨基酸的含量提高了13.64倍，其中天冬氨酸、亮氨酸、γ-氨基丁酸以及蛋氨酸、赖氨酸等增加显著；发酵过程中植酸酶活性增强，抗营养因子植酸的含量下降；发酵麦胚的脂肪酶活力比发酵前降低55.31%，脂肪氧化酶活力降低76.32%；顶空固相微萃取-气质联用（SPME-GC-MS）分析显示，发酵麦胚的贮藏特性发生显著改变，经过60 d的室温贮藏，发酵麦胚的氧化酸败程度明显低于未发酵麦胚。因此，乳酸菌发酵小麦胚芽可显著改善其营养品质与贮藏特性，采用该方法加工的小麦胚芽可作为食品营养强化的原料或食品配料。

Abstract:

Lactobacillus plantarum dy-1 was used as starters for the wheat germ fermentation, and the nutritional qualities and storage characteristics were analyzed. The results show that, Lactobacillus plantarum dy-1 had glutamate decarboxylase (GAD) activity, which was enabled to catalyze the irreversible decarboxylation of glutamate to γ-amino butyric acid. The concentration of free amino acids in Lactic acid bacteria fermented wheat germ increased by 13.64 times, especially aspartic acid, leucine, γ-amino butyric acid, methionine and lysine increased significantly; during the fermentation process, phytase activity increased, while phytic acid content decreased. Lipase activity after fermentation was 55.31% lower than that found in wheat germ, and lipoxygenase activity decreased by 76.32%. The SPME-GC-MS analysis indicated that, the storage characteristics of fermented wheat germ were significantly changed. After 60 days, the oxidative rancidity of fermented wheat germ was significantly lower than the unfermented. Therefore, Lactic acid bacteria could improve the nutritional qualities and storage characteristics of wheat germ, making the fermented wheat germ suitable to be food nutritional supplements or ingredients.