Zahra Hassanzadeh-Rostami, Seyed Mohammad Mazloomi, Samane Rahmdel, Asma Kazemi
"The current global burden of chronic diseases necessitates the introduction of new healthy food, including pro-biotic ones. Thus, the aim of the present study is to evaluate the suitability of different mixtures of soy and cow’s milk as probiotic food carriers. Soy milk prepared from soybeans was combined with cow’s milk at the concen-trations level of 0, 20, 40 and 60% (v/v). Lactobacillus acidophilus La-5, Lactobacillus casei and yogurt starter (Lac-tobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus) were used in a single culture for fermentation of different mixtures. Viable cell count, pH and titratable acidity of samples were determined on the first day after fermentation. The viable cell counts of all samples were over recommended levels for probiotic action (106cfu mL-1). While L. acidophilus exhibited the highest capacity to grow in the presence of soy milk, the lowest bacterial population was found in the mixture containing 60% soy milk and was fermented with yogurt starter (P>0.005). Samples inoculated with yogurt starter showed the lowest pH and the highest titratable acidity values; however, ones into which L. acidophilus was injected had the highest pH and the lowest titratable acidity values. The pre-sent study showed that mixtures of soy- and cow’s milk could serve as vessel for probiotics. However, more data are needed before industrial production. In order to achieve short fermentation time and pleasant fermented products, strain selection for ability to ferment mixture rapidly along with maintaining the significant probiotic yields should be taken in to consideration."
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