Atoosa Farrokh - Department of Food Science and Industry, Qazvin Branch, Islamic Azad University, Qazvin, Iran
Safieh Raeisi - Department of Food Science and Industry, Qazvin Branch, Islamic Azad University, Qazvin, Iran

Background and purpose: Dairy products as a carrier of functional compounds can beconsidered thefirst option for enrichment. Yogurt, as a fermented dairy product, is a suitable environment for the growthof probiotics and the addition of prebiotics. Quinoa flour can be used in food enrichment due to itsrichness in terms of nutritious and beneficial compounds.The purpose of this research is to produceprobiotic yogurt containing quinoa flour and Lactobacillus casei bacteria and then perform microbial teststo check its effectiveness and functional properties.Methods: In this research, ۲۵ samples of yogurt containing different amounts of quinoa and fat wereprepared with the desired probiotic bacteria (Lactobacillus casei). Probiotic yogurt samples producedwere optimized by considering the effect of three independent variables (fat percentage, quinoa flourpercentage, and storage time) to achieve the best production conditions and product shelf life. Then theirproperties and durability were checked by performing microbial tests such as counting the number ofprobiotic bacteria and sensory tests including color, smell, taste, and texture of yogurt on the first,seventh, fourteenth, and twenty-first days in order to quantitatively analyze the data. different phases ofdependent and independent variables) and measuring the effectiveness of quinoa flour consumption in theproduction of beneficial probiotic yogurt,Results: the results showed that the most suitable and reliable conditions for the production of probioticyogurt are the use of ۱.۶۸% quinoa flour and milk with fat ۷۷ ۱% in ۲۱ days of storage. The modelpresented to investigate the viability of Lactobacillus under study is a binomial model, and with theincrease in storage time, a significant increase in the number of bacteria was also observed. The results ofinvestigating the effect of quinoa flour on microbial growth show that despite its effect on bacterialgrowth, it was not significant at the ۹۵% confidence level. However, fermentation process, quinoa and fatpercentage, and storage time had significant effects on the microbial and sensory properties of probioticyogurt.Conclusion: According to the findings, it can be concluded that by choosing the right probiotic bacteriasuch as Lactobacillus casei and using the optimal level of quinoa and fat combination, it is possible toproduce probiotic yogurt with functional properties.

Probiotic yogurt, quinoa flour, functional, Lactobacillus casei