Effects of Starter Type and Barley Flour Replacement Level on Nutritional Characteristics of Kashk-e-Zard

Background and Objectives: Fermented foods play important roles in human nutrition. Kashk-e-Zard is one of the popular fermentation foods in Sistan and Baluchestan Province, Iran, which is prepared based on the fermentation of cereals with yogurt. The aim of this study was assessment of the effects of replacing barley flour with wheat flour and the type of starter culture on improving nutritional and sensory characteristics of Kashk-e-Zard.  Materials & Methods: In this study, effects of adding barley flour (0, 15 and 30%) and starter type (no inoculation, Saccharomyces cerevisiae PTCC 5052, Lactobacillus delbrueckii PTTC 1737, Lactobacillus plantarum PTCC 1058 alone and combinations of these strains) on pH, acidity, protein, digestible protein, phytic acid, zinc, availability of zinc, total phenol, antioxidant properties (DPPH) and overall acceptance of samples were assessed. Results: Results showed that all traits were affected by the type of starter and the level of replacement with barley flour (p < 0.05). By increasing barley flour replacements, quantities of protein, phytic acid and phenol and antioxidant characteristics increased, compared to the control sample (zero replacement level with no inoculation). Moreover, microbial inoculation decreased phytic acid content and increased protein digestibility, zinc uptake, antioxidant characteristics and overall acceptability, compared to the control sample (p <0.05). Conclusion: Regarding indicators of protein content, zinc uptake, protein digestibility and overall acceptance of the samples, a replacement level of 15% of barley flour with Lactobacillus plantarum and Saccharomyces cerevisiae is recommended for the preparation of Kashk-e-Zard.