ارزیابی زنده‌مانی باکتری‌های آغازگر و خصوصیات فیزیکوشیمیایی در ماست فراسودمند غنی شده با پودر جوانه گندم و مخلوط اسانس های فرآوری شده گیاهی.

According to the increasing demand of advanced societies for the consumption of functional foods, especially in dairy products, the use of natural -based materials such as plant essences in the field of enriching food products with their antimicrobial and antioxidant compounds, as well as the use of wheat germ powder as a rich source of dietary fibers and vitamins and minerals and their effects on the viability of starter bacteria (due to their prominent role in improving human health) are seem to be necessary. Investigating the effects of using processed essential oils and wheat germ powder simultaneously in yogurt is considered in this research. Sensory, physicochemical characteristics and bacterial conting of set yogurt including Streptococcus thermophilus and Lactobacillus bulgaricus, were tested during the storage period to study the simultaneous effect of plant essential oils and sprouted wheat powder. The essential oils used included tarragon and thyme with different proportions and at three levels (400, 1200, 2000 microliters per liter of yogurt). Yogurt physicochemical tests such as acidity and water holding capacity, hedonic sensory test, rheology test (apparent viscosity) and microbial count tests were conducted to check the viability of starter bacteria in yogurt during the 14 -day storage period. Based on the results obtained from the analysis of variance of the tested samples, the concentration of essential oil significantly (p<0.05) reduced the acidity and viability of starter bacteria of the product, but it had not a significant effect on the viscosity the sensory characteristics. In this regard, thyme and wheat germ powder showed a negative and unfavorable effect, especially in high concentrations. Thyme had a higher antimicrobial effect on yogurt starter bacteria, while tarragon showed less antimicrobial activity. The sensory score of samples containing tarragon has increased slightly during storage, so in general tarragon is prone to be used in yogurt production. Wheat germ powder first had an increasing and then decreasing effect on the acidity of the product during the storage time of yogurt. Also, the addition of wheat germ powder increases the viscosity and water holding capacity of the product, but in high amounts it reduces the sensory score, and therefore its use in yogurt should be controlled. In general, wheat germ powder has a positive effect on the viability of both starter bacteria counted in this research, which can be due to the supply of nutrients for their further growth. [ABSTRACT FROM AUTHOR]