燕麦发酵饮料乳酸菌菌种的筛选

Selection of Lactic Acid Bacterial Strains for a Fermented Oat Beverage

摘要:

选用保加利亚乳杆菌（Lb）、嗜热链球菌（St）、植物乳杆菌（Lp）和嗜酸乳杆菌（La）4种乳酸菌分别进行燕麦饮料发酵，考察不同乳酸菌发酵对燕麦发酵饮料的理化特性、营养成分及风味的影响，旨在筛选最适宜燕麦发酵饮料的乳酸菌菌种。研究结果表明：相对于其它3个菌种，菌种Lp产酸速率快，发酵后活菌数增加较多（3.89×109 cfu/mL），黏度（9.08 mp?s）与La（9.28 mp?s）无显著差异，却显著大于Lb（7.07 mp?s）和St（7.17 mp?s）菌种（p < 0.05）。发酵制备的燕麦发酵饮料中总酚含量高，为12.43 mg/100 ml，植酸含量低（16.49 mg/100 mL），β-葡聚糖含量与其它菌种发酵饮料差异不显著（p > 0.05）。GC-MS分析结果表明Lp发酵后的燕麦饮料产生较多的醛类，醇类以及有机酸等挥发性风味成分，使燕麦发酵饮料拥有较为独特的口感，其感官评分也最高。因此，筛选出菌种Lp为最适宜的燕麦发酵饮料乳酸菌菌种。

Abstract:

The most suitable strain of lactic acid bacteria from four different species, Lactobacillus bulgaricus (Lb), Streptococcus thermophilus (St), L. plantarum (Lp), and L. acidophilus (La), was selected to prepare a fermented oat beverage. The effects of the bacteria on the physicochemical properties, nutritional components, and taste and flavor of the oat beverage were investigated. Compared with the other three strains, Lp showed a faster acid production rate and a larger increase in viable cell count (3.89 × 109 cfu/mL). The viscosity (9.08 mp?s) of the beverage prepared using Lp showed no significant difference from that prepared using La (9.28 mp?s) (p < 0.05), but was significantly higher than those using Lb (7.07 mp?s) and St (7.17 mp?s) (p < 0.05). The oat beverage fermented by Lp showed high content of total phenols (12.43 mg/100 mL), low content of phytic acid (16.49 mg/100 mL), and no significant difference in β-glucan content when compared with beverages prepared using other bacteria (p > 0.05). The results of gas chromatography–mass spectrometry (GC-MS) showed that after Lp fermentation, a larger quantity of aldehydes, alcohols, organic acids, and other volatile flavor components were produced, giving the fermented oat beverage a unique taste and the highest sensory score. Therefore, Lp was chosen as the most suitable lactic acid bacterial strain to prepare the fermented oat beverage.