Comprehensive Evaluation of Nutritional, Phytochemical, and Functional Properties of Watermelon-Tiger Nut Juice Blends

Abstract

The study investigated the physicochemical properties, phytochemical composition, antioxidants activity, and sensory quality of ready-to-serve beverage produced from blends of watermelon and tiger nut juices. Watermelon and tiger nut were separately processed into juices blended at the ratios of 50:50, 60:40, 70:30, 80:20, 90:10, 100:0 and 0:100 (tiger nut: watermelon juice). The blended juices were separately pasteurized at 72°C for 15 min, cooled, filled into sterile glass bottles, labeled and stored at 4°C then subjected to the various analyses. The results revealed that all the blends in ratio had high amount of moisture from (65.82-69.11); protein (9.46-18.36); fat (3.7-7.08); ash (0.15-0.50) and carbohydrate (7.76-16.6). The mineral results reveal blends were significantly high in in magnesium, calcium and potassium but have lower value of phosphorus and zinc. The pH of the blends reveals that the blends has a shelf life with a range from 5.30 to 5.87, it’s also has a high value of total soluble solids and total titratable acid with a range of 10.35- 15.80 and 0.46 to.87 respectively. The phytochemical results reveal that all blends are rich in phenol and carotenoids which are abundant in water melon and increases in the blend because of the increasing ratio of water melon in each blend and are lower in flavonoids. The sensory evaluation results reveal that the entire blend is acceptable in taste, color, consistency, flavors and can be consumed but the blends that is generally acceptable by all and has the highest value is the 50:50% blends. From the result obtained the water melon has a very high value of vitamin C which is incorporated to each blend in different ratio that increases the vitamin C in each of the blends. Tiger nut has the highest values of DPPH and FRAP. At the end of the research it’s recommended that further work should be carried out on the antioxidant properties, medicinal properties and storage stability of the beverage to determine shelf life.