Formulation and Evaluation of Ready–to–Serve Beverage from Blends of Watermelon, Pineapple and Tiger Nut Juices

Abstract

Aim: The present study was aimed at assessing the physical properties, nutritional composition, microbial and sensory quality of ready-to-serve beverage produced from blends of watermelon, pineapple and tiger nut juices. Study Design: Complete randomized design was used. Place and Duration: Department of Food Science and Technology, University of Uyo, Akwa Ibom State, Nigeria, from October 2017 to April 2018. Methodology: Watermelon, pineapple and tiger nut were separately processed into juice. The three juices were blended at the ratios of 50:50:00(T0), 33.33:33.33:33.33(T1), 50:25:25(T2), 25:50:25(T3) and 25:25:50(T4) (watermelon: pineapple: tiger nut juice). The blended juices were separately pasteurized at 80°C for 15 min, cooled, filled into sterile glass bottles, labeled and stored at 4°C prior to analysis. Results: The result revealed that all the parameters except total coliform count varied with the proportion of individual juice in the blends. The pH, total soluble solids and titratable acidity ranged from 5.60 – 5.32, 10.60 – 12.39 oBrix and 0.32 – 0.58% respectively. The moisture, crude protein, fat, and ash contents of the blends ranged from 87.51 – 89.84%, 0.85 – 1.90%, 0.34 – 1.20% and 0.40 – 0.52% respectively. Incorporation of tiger nut juice significantly (p=.05) increased the protein and fat contents in the beverage. The vitamin C and beta-carotene contents ranged from 21.58 – 36.62 mg/100 mL and 121.05 – 144.00 mg/100 mL respectively. Potassium, calcium, magnesium and zinc contents ranged from 70.39 – 122.38 mg/100 mL, 9.92 – 13.50 mg/100 mL, 8.27 – 18.39 mg/100 mL and 0.47 – 0.55 mg/100 mL respectively. The total viable counts and fungal counts ranged from 0.7 x 102 – 1.4 x 102 cfu/mL and 0.9 x 102 – 1.5 x 102cfu/mL respectively. No coliform growth was detected in all the beverages. Mean scores for sensory evaluation showed that samples T1 and T3 were the most acceptable samples. Conclusion: The results showed that acceptable beverage of higher protein content could be produced by supplementing watermelon and pineapple juice blend with 25 to 33.33% of tiger nut juice.