Evaluating physicochemical and microbial properties of synbiotic yogurt using Response surface methodology

Nowadays yogurt is produced as the most important probiotic dairy product around the world. Probiotics are alive microorganisms that when consumed in sufficient quantities on a regular basis, have beneficial effects on the health of their host. Also, prebiotics are indigestible carbohydrate compounds for human that have ability to improve growth or activity of one or a limited number of probiotic bacteria (Enteric bacteria). Combination of prebiotic and probiotic is called symbiotic that consult health benefits. Nowadays yogurt is produced as the most important probiotic dairy product around the world. Probiotics are alive microorganisms that when consumed in sufficient quantities on a regular basis, have beneficial effects on the health of their host. Also, prebiotics are indigestible carbohydrate compounds for human that have ability to improve growth or activity of one or a limited number of probiotic bacteria (Enteric bacteria). Combination of prebiotic and probiotic is called symbiotic that consult health benefits. Nowadays yogurt is produced as the most important probiotic dairy product around the world. Probiotics are alive microorganisms that when consumed in sufficient quantities on a regular basis, have beneficial effects on the health of their host. Also, prebiotics are indigestible carbohydrate compounds for human that have ability to improve growth or activity of one or a limited number of probiotic bacteria (Enteric bacteria). Combination of prebiotic and probiotic is called symbiotic that consult health benefits. In this study Lactobacillus acidophilus type LA5 was used as probiotic culture. To determine optimal conditions of symbiotic yogurt production, three factors including inulin concentration (0-2/5%), gum tragacanth concentration (0-0/06%) and shelf life (1-19 day) was considered as independent variables and their effects on hardness, synersis and probiotic count sample used analyze response surface method. The overall coefficient of determination (R2) for hardness, Synersis and probiotic count characteristics were 0/98, 0/98 and 0/99 respectively. Analysis of variances of overall effect variables process in regression model Synbiotic yogurt showed significant effect of each independent variable on the dependent variables. Optimum conditions in Synbiotict yogurt for maximum hardness and probiotics count and the least Synersis determined combination 2/5% inulin with 0/04% Gum tragacanth in 18 days. In relation hardness and probiotics count increasing concentration inulin and shelf life improves the texture. Increasing tragacanth Gum concentration to 0/03% improves the texture while the concentration of 0/06% had negative effects. The increasing tragacanth Gum and inulin concentration have positive effect on the probiotic count, but in maintenance time probiotics count reduced.