Investigation of Physicochemical, Rheological and Microbial Properties of Symbiotic Tomato Sauce

Tomato sauce is a widely used product in the world and in Iran that is widely used in various foods, especially fast food. In this regard, the preparation of symbiotic products from it will promote health.In this study, 3 levels of lactulose (0, 1 and 2%) and 3 levels of wheat fiber (0, 1.5 and 2.5%) were used as prebiotics and Lactobacillus acidophilus (La-5) was used as a probiotic.The results showed that the pH of the samples containing microencapsulated bacteria was lower than the samples containing free bacteria and similar to the control. The rate of syneresis of all samples was significantly different from the control (p <0.05). But rate of syneresis of microencapsulated samples was less than free. In terms of viscosity, except for the microencapsulated sample containing 2% lactulose and 2.5% fiber, there was a significant difference between the other samples and the control (p <0.05). In terms of microbial evaluation, the rate of bacterial reduction in treated samples was equal to one and in control two logarithmic cycles. Survival of microencapsulated probiotic bacteria was higher than free probiotic bacteria and had a significant difference with the control (p <0.05). The highest survival rate with microbial count of 5.023 × 107 cfu / ml was related to the sample containing 2% lactulose and 2.5% fiber in microencapsulated samples, Therefore, in addition to being superior to other samples in terms of physicochemical and rheological properties, the above sample is also considered a symbiotic product.