Effect of banana and ABT-2 probiotic culture use on quality parameters and microstructure of buffalo yoghurt

Yoghurt, whose positive health benefits have been proven and whose consumption rate is increasing day by day, is one of the most popular dairy products consumed by consumers. Although cow's milk is often preferred in yoghurt production, buffalo milk, whose consumption as drinking milk is quite limited, is very suitable for yoghurt production due to its unique composition and textural properties. However, in order to relatively suppress the unique organoleptic properties of buffalo milk and present it to the consumer as a new product, the addition of fruit is a suitable method. Among the fruits to be added to yoghurt, banana stands out especially with its prebiotic content and desirable sensory properties. In this context, in the present study, the changes in some quality characteristics and microstructures of experimental yoghurts, produced with ABT-2 and YC-350 starter cultures and five different banana-sugar combinations, were researched during storage period. According to the results, it was seen that the use of different starter cultures had a very significant effect (p<0.01) on viscosity, syneresis, titratable acidity, pH, and all sensory parameters, and had a significant effect (p<0.05) on ash content. It was determined that the fruit ratio had a very significant effect (p<0.01) on all physicochemical, microbiological, and sensory analyses. It was observed that sugar ratio had a very significant effect (p<0.01) on total solids, fat, solids nonfat, protein, viscosity, syneresis, pH, and all sensory parameters, while it had a significant effect (p<0.05) on the counts of S. thermophilus, L. delbrueckii subsp. bulgaricus and B. animalis subsp. lactis BB-12. It was observed that the storage period had a very significant effect (p<0.01) on all analyses except solids nonfat (p<0.05). In the SEM investigations, different banana-sugar ratios, storage times, and starter cultures caused the formation of different levels of microstructures in experimental yoghurts. As a result of the study, it was observed that the addition of banana and sugar caused larger gap diameter and number due to increased syneresis. In this context, it was revealed that the addition of banana and sugar to yoghurts produced from buffalo milk supported the nutritional value and probiotics, while causing partial deterioration in microstructure. It was observed that the storage period had negative effects on nutritional value and probiotic microorganisms.