Microbiological and Some Sensory Attributes of Water Melon Juice and Watermelon-orange Juice Mix

Abstract

Juice was produced from watermelon and stored at room (28±2°C) and refrigeration (8°C) temperatures and was analyzed for its microbiological and nutritional qualities. The total aerobic bacterial, coliform, mold and yeast counts increased with time. Total aerobic bacterial counts ranged from 1.5×102 to 3.6×103 for water melon juice (WM), 1.3×103 to 2.3×102 for water melon/orange juice mix (WO) and 1.0×103 to 2.9×102 for commercially packaged juice (ST). Coliform counts were 1.0×103 to 2.9×102 for WM, 2.1×102 to 2.3×103 for WO and no counts were recorded for ST, while the yeast counts ranged from 2.4×102 to 2.6×103 for WM, 2.4×103 to 3.2×103 for WO and 0 to 1.2×102 for ST. Bacteria isolated were Bacillus sp. Staphylococcus aureus, Klebsiella sp. and Pseudomonas sp., while the mold isolates were Aspergillus niger, Aspergillus flavus and Mucor sp. The yeast isolate was Saccharomyces cerevisiae. Vitamin C and total solid contents decreased with time while total titratable acidity and ash content increased on storage in freshly made juice samples, commercially packaged juice which served as a control showed negligible changes. The general acceptability tests revealed that the commercially packaged juice (ST) was preferred on account of taste and flavor while water melon juice (WM) was preferred based on colour. The water melon/orange juice mix (WO) was however, not preferred because of colour, flavor and taste.