Ayran-shalgam mixture: A study on rheological properties, shelf life, and sensory evaluation

The objectives of this study were to evaluate the rheological properties, shelf life and sensory properties of different ayran-shalgam mixtures. Mixtures of ayran and shalgam in different ratios [25% ayran + 75% shalgam (v/v), 50% ayran + 50% shalgam (v/v) and 75% ayran + 25% shalgam (v/v)] were subjected to rheological measurements at different temperature levels (4, 8 and 12 °C). Power law model was used to define the rheological data. It was apparent that temperature had no effect on the flow behavior index of the mixtures. On the other hand, as the temperature increased consistency index of the mixtures decreased. Ayran-shalgam mixtures had similar flow behavior index with that of shalgam no matter whatever the amount of ayran or shalgam in the mixtures was. However, consistency index increased as the amount of ayran increased in the mixtures at a constant temperature. Shelf life analyses up to 4 weeks at 4 °C indicated that serum separation increased up to second week and then stabilized for all the mixtures. Slight increase (0.05 to 0.1 unit) in the pH values was observed during the first week, then, pH values were stabilized just like the serum separation. Microbiological analyses revealed that mixtures had a similar shelf life with that of ayran. Mixture with the highest ayran content [75% ayran + 25% shalgam (v/v)] had the highest scores in sensory evaluation. It was concluded that ayran-shalgam mixture had a huge potential for commercial production. Key Words: Ayran, Shalgam, Fermented Beverages, Rheology, Shelf life, Microbiology