Probiotic shelf life, antioxidant, sensory, physical and chemical properties of yogurts produced with lactobacillus acidophilus and green tea powder

Abstract

The aim of the present study was to determine the effects of the addition of green tea powder (GTP) in the production of yogurt on survival of Lactobacillus acidophilus (P) and the yogurt properties. Four yogurt groups (yogurt without P and GTP, Control, C; yogurt with P and without GTP, PC; P + 1% GTP; and P + 2% GTP) were produced. The yogurt samples were stored at 4°C. The addition of GTP into milk did not affect the viability of yogurt bacteria during fermentation. The highest count of L. acidophilus was detected in P + 2% GTP. The L. acidophilus count was high up to the 7th day (7.54 log cfu/g). Yeast and mold were not counted (<2 log cfu/g) in any yogurt sample during storage. GTP has antioxidant properties that could be attributed to the presence of phenolic and flavonoids compounds. The panelists preferred the PC and P + 1% GTP samples during the storage period. As a result of this research, we can suggest the consumption and production of probiotic yogurt with 1% GTP supplement.

Keywords

• yogurt
• green tea powder
• lactobacillus acidophilus
• shelf life
• antioxidant activity
• phenolic compounds