Abstract

Physicochemical, microbiological and sensory characteristics of strawberry yoghurt fortified with Red beet extract..

Author(s): Mohammad Sayadi Shahraki, Ali Mohamadi Sani, Mohammad Hojjatoleslamy

This research conducted to optimize the formul of fruit yoghurt with different levels of red beet extract (1.25%, 2.5% and 4%) and strawberry flavor (1%, 2%and 4%). Physico-chemical and microbiological characteristics were analyzed to assay the quality of the yoghurt samples. Results showed higher syneresis and lower viscosities in red beet-flavored yogurts compared to the control sample and this effect was found to be concentration-dependent. The titratable acidity of red beet-flavored yogurt containing 2.5% red beet extract was found lower than the samples containing 1.25 and 4% extract and control, while the acidity of red beetflavored yogurt containing 1.25 and 4% red beet extract was higher than the control. The pH of all the samples and control continued to decrease during storage period. Higher concentrations of red beet extract resulted in more decrease in pH. During 21 days of refrigeration storage, pH and LAB count decreased and titratable acidity increased. Panelists gave higher scores to the yogurt with 2.5% red beet extract, and no significant difference was observed between scores of yogurts produced by adding 1.25 and 4% red beet extract. The overall acceptability values of the yogurts containing 2.5%red beet extract and 2%strawberry flavor was found to be higher than the other types of red beet-flavored yogurts.