PRODUCTION AND EVALUATION OF FLAVORED YOGHURT FROM GRADED LEVELS OD SOURSOP (ANNONA MURICATA) PULP

Abstract

Yoghurt was produced and flavoured with graded levels of soursop pulp. Soursop pulp was used to substitute 0, 10, 20, 30, 40 and 50% of yoghurt. The chemical, sensory and microbiological properties of the yoghurts were determined. The results showed that the pH of the yoghurt ranged from 4.30 to 4.60. The protein content varied from 2.68%-5.83% and the ash content ranged from 1.21% - 1.38%. The fat and moisture contents decreased and the values varied from 2.21% - 4.12% and 74.57%- 79.26% respectively. However, the carbohydrate and micro-nutrient (Ca and Vitamin C) content increased with increased level of soursop in the yoghurt. The total viable count and lactic acid bacteria count values were also inversely proportional to the concentration of soursop. The values for Total viable count (TVC) ranged from 2.0×105-4.5×105 while the values for Lactic acid bacteria (LAB) varied from1.3×105-3.9×105. There was no significant difference (p < 0.05) in the overall acceptability of all the products. The most acceptable flavoured yoghurt contained 60% yoghurt and 40% soursop pulp and had a general acceptability of 7.15. Soursop could be used to produce acceptable beverage.
Key words: Flavoured yoghurt, Micro-organisms, Micro-nutrient, Soursop pulp, Sensory evaluation