Chemicaland physicochemical compositions of yoghurts produced from blends of cow milk and pineapple juice

Abstract

Introduction: Yoghurt is a fermented semi-liquid diary product known for its health benefits and functional properties; It however lacks some phytochemical which when present could enhance its functionalities.

Objective: The study determined the nutrient and physicochemical of yoghurts produced with cow milk and pineapple juice blends.

Methods: Cow milk powder (100, 90, 70, 50 and 30g) reconstituted with 900mls of potable water each was mixed with graded levels (0, 10, 30, 50 and 70 ml, respectively) of pineapple juice. Using standard method, a mixture of L. bulgaricus and S. thermophilus was incorporated into each reconstituted sample to produce yoghurt. The chemical composition of the yoghurt samples was determined in duplicate using the AOAC methods. The data generated were analysed using Statistical product for service solution version 20, means were separated and compared with Duncan multiple range test and Analysis of Variance, respectively.

Results: Moisture (79.6-87.4%), β-carotene (20.6-48-7μg), thiamin (2.10-3.92mg), riboflavin (0.65-1.02mg) and ascorbic acid (128.9-150.7mg) values were significantly (p < 0.05) higher in the cow milk and pineapple juice yoghurt blends, while protein (3.9%), fat (4.0%), crude fibre (0.40%), Ca (124 mg), Mg (142.1mg), P (164.6mg), Na (68.5mg) and K (54.7mg) were significantly (p < 0.05) higher in the 100% cow milk yoghurt. The titratable acidity increased with decease in pH of the products.

Conclusion: Proximate (except for moisture) and mineral contents decreased with increase in the proportion of pineapple juice added while the reverse was the case for vitamins and phytochemicals. Incorporating pineapple juice in yoghurt could enhance vitamin and phytochemical intakes of individuals.

Keywords: Yogurt, nutrient, enrichment, pineapple juice, phytochemicals