Antioxidant, physicochemical, microbiological, and sensory properties of probiotic yoghurt incorporated with various Annona species pulp

In this study, antioxidant, chemical, microbiological, and sensory attributes changes taking place during the production of probiotic yoghurt using pulp of soursop (Annona muricata), sweetsop (Annona squamosa), and custard apple (Annona reticulata) were evaluated. The products were stored at 4 °C for 28 d, during which time physicochemical properties and viability of probiotic bacteria and yoghurt starter cultures were evaluated weekly. Yoghurts prepared with fruit pulps displayed higher antioxidant activities on the first day of storage compared to the control. During the storage, the addition of fruit pulps influenced (p < 0.05) pH, titratable acidity, syneresis and counts of B. animalis ssp. lactis BB-12 of yoghurts, whereas counts of Streptococcus thermophiles and Lactobacillus delbrueckii ssp. bulgaricus were found to be insignificant. Sensory evaluation results showed that yoghurt containing soursop fruit pulp had better sensory scores than other treatments. Therefore, these results proved that soursop can be used to produce probiotic yoghurt with enhanced physicochemical, microbiological and sensory properties.