Quality Characteristics of Whole Barley Flour Added to Yogurt During Storage

Quality characteristics were evaluated for whole barley yogurt prepared with lactic acid bacteria combination such as Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. Bulgaricus, and Streptococcus thermophilussei (1:1:1) with the addition of whole barley flour at 3%. The barley yogurt had lower pH, higher titratable acidity, and higher sugar content than control yogurt. The viable cell number of the barley yogurt was lower than the control yogurt. However, the viscosity and antioxidant activity of the barley yogurt were higher than those of the control yogurt. In up to 12 d of storage at 4oC, pH decreased while titratable acidity increased in both control yogurt and barley yogurt. The sugar content and brightness increased slightly. The viable cell number of the barley yogurt decreased during storage. However, the viable cell number of the barley yogurt met the standard suggested by the KFDA. Although the viscosity of the barley yogurt decreased, it corresponded to the required viscosity of a curd yogurt. Antioxidant activity slightly increased up to 9 d and then decreased, but the decrease of antioxidant activity was smaller in barley yogurt than in the control yogurt. During storage, there was no curd separation, change in scent, etc. Thus the storage quality of barley yogurt was relatively good.