Effects of prickly pear supplementation on physico-chemical, textural, microbiological and sensory characteristics of probiotic set yoghurts

Probiotic set yogurts were produced by adding prickly pear fruit pulp to cow ' s milk at different ratios (0%, 6%, 8% and 10%). The resultant yoghurts were stored at 4 degrees C for a maximum of 2 weeks. During the storage, physicochemical, textural, microbiological and sensory characteristics, colour and mineral profiles of the experimental yoghurts were analysed at 1st, 7th and 14th days. Prickly pear supplementations significantly influenced pH, syneresis, water holding capacity, L*, a*, b* values, firmness, consistency, cohesiveness, viscosity index and the number of Lactobacillus delbrueckii subsp. bulgaricus , Streptococcus thermophilus and Lactobacillus rhamnosus promoting the growth and development of probiotic bacteria as well as increasing amounts of mineral contents in the yoghurts. Besides, carotenoid (0.41 - 0.63 mg/kg), phenolic (32.9 - 65.1 mgGAE/kg) and betalain (1.84 - 2.55 mg/kg) contents of the supplemented yogurts were significantly higher than the control samples (p < 0.05). Consequently, the set yoghurts supplemented with prickly pear fruit pulp have consumable quality, and the results highlighted that prickly pear pulp with 8% can be added to improve bioactive compounds of the probiotic-set yoghurt.