Effect of Fermentation on the Proximate Composition and Physicochemical Properties of Blends of Watermelon and Tigernut Juice

Abstract

Tigernut tuber and Watermelon fruit are common substrates found in Nigeria. This study analyzed the proximate and physicochemical properties in a consortia of fermenting Tigernut and Watermelon blends. The substrates used were processed and evenly divided into three sterile fermenters each containing three litres of the blended substrates. The substrates was allowed to undergo spontaneous fermentation via the action of wild yeast (Chance inoculation) for 5 days (primary fermentation) after which the mixtures were sieved with a muslin cloth and transferred into a secondary fermenter and allowed to ferment for 4 weeks. The fermented samples had an initial pH of 6.51±0.00, 6.43±0.00, 6.67±0.00 which later got reduced at the end of the fermentation to 3.15±0.00, 3.16±0.00, 3.22±0.00 in Samples A, B and C respectively. The Total Titrable Acid increased from 0.49±0.02g/L to 0.96±0.13g/L, 0.34±0.02g/L to 1.52±0.24g/L, 0.40±0.07g/L to 1.45±0.29g/L for samples A, B and C respectively. For the proximate composition of the substrates, The Ash content reduced from an initial value of 0.70 to 0.48%, 0.80 to 0.44% for samples A and C but got increased in sample B with value of 0.36 to 0.37%. The crude Fat reduced from 1.53 to 0.46%, 1.30 to 0.30% and 2.17 to 0.26% for samples A, B and C respectively. The crude Protein reduced from 2.21 to 1.31%, and 2.18 to 2.06% for samples A and C respectively but got increased in sample B with values of 1.64% to 1.88%. While the total carbohydrate reduced from an initial 7.09 to 0.74%, 4.16 to 0.00% and 13.67 to 0.00% for samples A, B and C respectively. This study shows that the resulting product had low fat content which could provide protection against excess body lipids.