Abstrakt

Effect of Spinacia oleracea extract on physicochemical, phenolic content, antioxidant activity and microbial properties of yogurt

Jafar Hayaty Nejad, Ali Mohamadi Sani, Mohammad Hojjatoleslamy

Yogurt flavored with kiwi flavor (1, 2 and 4%) and colored with spinach extract (1.25, 2.5 and 4%) and a control yogurt (no kiwi flavor or spinach extract) were evaluated for some chemical characteristics, viscosity, syneresis, L*, a* and b* color values and microbial properties at sevenday intervals for 21 days. Significant differences were found between the control and kiwi-spinach yogurt with respect to syneresis and viscosity characteristics (P<0.05). Increasing the amount of spinach extract in yogurt resulted in a decrease in L*, a* values of yogurt, and increase in b* color, syneresis, total phenolic content, antioxidant activity, titratable acidity and viscosity parameters (P<0.05). During the storage period, pH decreased but titratable acidity, syneresis and viscosity values of yogurt samples increased continuously (P<0.05). Storage affected LAB count significantly (P<0.05).