SENSORY AND CHEMICAL EVALUATION OF YOGHURT FORTIFIED WITH PINEAPPLE JUICE

Abstract

Yoghurt is a coagulated milk product obtained by controlled fermentation of lactose in milk by the action of Lactobacillus bulgaricus and Streptococcus thermophiles. Improvement of the sensory characteristics of yoghurt has been accessed with sucrose to enhance sweetness, cream to provide smoother texture with limited information on the use of fruit juices. This study was therefore carried out to access the effect of fruit (pineapple juice) on the taste and flavor of yoghurt. Yoghurt was prepared with ripe cayenne pineapple juice incorporated at different levels; T1: 0% (Plain yoghurt), T2: 0% (2% synthetic flavour), T3: 5%, T4: 10% and T5: 15%. Yoghurt samples were analyzed for proximate and nutritional composition as well as sensory properties. Yoghurt with 15% pineapple juice had the lowest fat (5.19%) and pH (4.05) values and was significantly different (p< 0.05) from other treatments. There were significant differences (p< 0.05) in the mean values of crude protein, fats and ash of the yoghurt samples. Crude protein, fats and ash values were significantly different (p< 0.05). Crude fibre values for 5, 10 and 15% were not significantly different (p>0.05) from each other but 15% pineapple juice yoghurt had the highest crude fibre value (0.19%). There was no significant difference (P>0.05) in the mean values for odour, colour and texture of yoghurt samples while 15% pineapple juice yoghurt had the highest score for taste (5.10). Graded levels of pineapple juice had an impact on the proximate and nutritional compositions, and also the sensory properties of yoghurt.