Abstract In this study, non-fermented probiotic grape juices were produced with the inoculation of two different strains of lactic acid bacteria (Lactobacillus fermentum CECT 5716 and Lactobacillus acidophilus DSM 20079) separately. The viability of probiotic microorganisms, as well as the grape juices’ physicochemical properties were evaluated throughout 21 days of storage at 4 °C. In grape juice, both strains had similar survival rates, and viable cell counts remained above the recommended therapeutic minimum (107 CFU mL-1) throughout the monitored storage time. Both of the probiotic samples showed a drop in pH, total phenolic content and viscosity during storage, as well as an increase in acidity. The values of lightness, redness, and yellowness in grape juice containing L. acidophilus DSM 20079 were reduced over cold storage period; otherwise, color characteristics for the control and sample with added L. fermentum CECT 5716 were maintained. This study showed that grape juice is an effective vehicle for delivering the Lactobacillus strains studied, with their probiotic activity remaining for 21 days at 4 oC, making it a probiotic beverage alternative for non-dairy product users. Furthermore, L. fermentum CECT 5716 can be more suitable due to its maintenance of color properties in grape juice over the storage.

Abstract Tarhana is known as a fermented cereal product made traditionally from wheat flour and yoghurt. As a novelty, kefir was used as substitute for yoghurt in tarhana production partially and completely to investigate the effects on fermentation activity, nutritional, sensory and rheological properties of tarhana. Addition of kefir increased the fermentation activity as raise in acidity values was observed compared to tarhana samples prepared with yoghurt. Regarding dry tarhana samples, the highest acidity degree, protein, ash and phenolic contents were detected in samples prepared with 100% kefir. Counts of LAB groups (M17 and MRS agar) of tarhana enriched with 100% kefir was higher than that of other tarhana samples during the fermentation period. Moreover, kefir affected the scores of sensory properties of tarhana soups. Tarhana soups prepared with kefir gave the highest scores for mouth feel, odour and consistency attributes. Tarhana soup prepared with 50% yoghurt and kefir showed the lowest viscosity probably due to synergistic effect on starch hydrolysis by bacterial population from both ingredients. These results suggest that replacement of yogurt with kefir in the formulation of Tarhana may enhance some properties of the soup.