Quality Characteristics of Whole Barley Flour Added Yogurt Made with Various Lactic Acid Bacteria

The objective of this experiment was to select the best strain of lactic acid bacteria for the manufacture of yogurt with 3% whole barley flour. Yogurt was fermented with various lactic acid bacteria, Lactobacillus acidophilus (LA), Lactobacillus delbrueckii subsp. Bulgaricus (LB), and Streptococcus thermophilussei (ST), and quality properties, β-glucan content, and antioxidant activity were estimated. The quality of the control yogurt and that containing barley flour showed significant differences according to the type of lactic acid bacteria strain. Barley yogurt that was fermented with LALBST complex bacteria had low pH, high titratable acidity and brix. Also, its viable cell count, the value of L, and antioxidant activity were high, and the value of a and b were low. The β-glucan content of barley yogurt containing 3% whole barley flour was 0.15%. The pH of yogurt decreased with the addition of barley flour. Titratable acidity, brix, β-glucan content, and the antioxidant activity of yogurt fermented with barley flour increased. Viscosity also increased significantly with the addition of barley flour. Yogurt qualities such as pH, titratable acidity, and viscosity were developed by the addition of barley flour. From these results, the best strain of lactic acid bacteria for fermenting yogurt containing barley flour was the LALBST complex.