Evaluation of the Effects of Aloe Vera Extract on Chemical and Microbial Properties of Low Fat Stirred Probiotic Yoghurt

Yogurt is a fermented dairy product, which is a popular product throughout the world and has positive effects on public health, due to its nutritional properties. Aloe vera extract is a kind of vegetable derivative, which has high nutritional value and antibacterial properties. In this research the effects of Aloe vera extract (0.5, 1, 1.5, 2% w/w) addition on the textural (syneresis), chemical (pH, acidity), viability of yoghurt probiotic microorganisms, yeast and mold, antioxidant properties and sensorial attributes of stirred probiotic yogurts were investigated during the shelf life (1st, 7th, 14th and 21thday of production). The results showed addition of Aloe vera extract decreased the pH value and increased acidity but decreased syneresis. Bifidobacterium and Lactobacillus viability increased with Aloe Vera extract addition but yeast and mold counts decreased. The addition of Aloe vera extract increased antioxidant properties of yoghurt. Sensorial analysis indicated that panelists preferred yogurt samples with low Aloe vera extract rates. However, higher rates of Aloe vera extract affected the flavor and overall acceptability and lowered their panelist scores. During time, pH decreased and acidity and syneresis increased. Overall, it was concluded that the best treatment from all aspects, was 0.5% Aloe vera extract.