Selection of Lactic Acid Bacterial Strains for a Fermented Oat Beverage

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 × 10~9 cfu/m L). 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 m L), low content of phytic acid(16.49 mg/100 m L), 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.