PRODUCTION AND QUALITY EVALUATION OF SPOONABLE AND DRINKABLE YOGHURT WITH WATERMELON (CITRULLUS LANATUS) JUICE AND PULP

PRODUCTION AND QUALITY EVALUATION OF SPOONABLE AND DRINKABLE YOGHURT WITH WATERMELON (CITRULLUS LANATUS) JUICE AND PULP

ABSTRACT

Yoghurt was produced and flavoured with graded levels of watermelon pulp and juice. Watermelon (Citrullus lanatus) juice and 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 4.68 to 4.90. The protein, ash, and fat content decreased with increase in watermelon juice and pulp.  The fiber content increased with the watermelon pulp while the moisture content increased with increase in watermelon juice. Micro-nutrient (vitamin A and C) increased with increased level watermelon juice and pulp in the yoghurt while sodium decreased with increased level watermelon juice and pulp in the yoghurt. Lactose content increased with increased watermelon juice and pulp content of the formulated yoghurt. The total viable count and lactic acid bacteria ranged from 1.15×105 to 2.1 ×105cfu/ml and   3.8×103   to 1.3 x 104cfu/ml, respectively. High mean values (8.35) were obtained for the plain yoghurt (control) for all sensory attributes (colour, flavour, taste, aftertaste, consistency and mouthfeel), therefore making the plain yoghurt most preferred sample with an overall acceptability of 8.35. Sample PY+ WMJ (90:10) had the highest mean for general acceptability (7.00) compared to the other flavoured yoghurt in overall preference. Samples containing 10 and 20 % of watermelon pulp and juice in yoghurt were generally acceptable while samples containing 30, 40 and 50 % of the juice were generally unacceptable.  There was no significant (p<0.05) difference between the plain yoghurt and the flavoured yoghurt sample PY+WMJ (90:10) while the difference with the flavoured yoghurt containing 10 % watermelon pulp was significant (p<0.05).