Goats' milk yogurt with passion fruit pulp: Impact of the addition on antioxidant activity, physico-chemical and sensory properties

Passion fruit is now grown worldwide as a delicious edible fruit for the food industry. In order to analyse the influence of the addition of passion fruit pulp on the quality of goats' milk yogurt, the physico-chemical, sensory and antioxidant properties of the yogurt during refrigerated storage were investigated by measuring pH value, titratable acidity, susceptibility to syneresis, viscosity, hardness and antioxidant capacity. The results showed that supplementation with passion fruit pulp improved some of the physico-chemical and sensory characteristics. During 2 weeks of storage, viscosity and susceptibility to syneresis continuously increased and hardness was higher compared to that of the con-trol group. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and OH radical-scavenging rate as well as Fe3+ reducing capacity increased, goats' milk yogurt with 20 g.kg(-1) passion fruit pulp showed a higher antioxidant activity. However, pH of the yogurt decreased. Overall, the results support the hypothesis that passion fruit pulp is a promising option as a dietary supplement to produce novel dairy products that have high nutritional value and high antioxidant activity.