Storage studies of table wine produced from African bush mango (Irvingia gabonensis) and watermelon (Citrullus lanatus) blends

Abstract

The work was carried out to study the storage characteristics of table wine formulated from blends of African bush mango (Irvingia gabonensis) and watermelon juice. The juices of watermelon (WM) and African bush mango (UG) were extracted, weighed, blended together in the ratios: 100: 0, 90: 10, 80: 20, 70: 30, 60: 40, 50: 50 and 0: 100 to each other and fermented with yeast to obtain watermelon-ugiri wine. The formulated table wine was subjected to sensory evaluation, physicochemical, microbial and proximate analyses for a period of four weeks. Sensory evaluation on the formulated table wine showed that sample UGWM2 (containing 100 % watermelon) had the most acceptable mean score with 7.5 in week zero and 7.3 in week four for colour while sample UGWM7 (containing 50 % African bush mango + 50 % watermelon) was however rated lower than other samples for all sensory parameters both in week zero and week four. The highest total viable count was 8.9 × 105 cfu/ml in sample UGWM5 (containing 70 % watermelon + 30 % African bush mango) for week zero while it reduced to 3.1 × 104 cfu/ml in week four. In the proximate composition, sample UGWM1 (containing 100 % African bush mango) had the highest fat content with 4.65 % in week zero and 3.95 % in week four. The moisture content was found to be in the range of 90.91 % in sample UGWM4 to 93.25 % in sample UGWM2 in week zero and 91.19 % UGWM4 (containing 80 % watermelon + 20 % African bush mango) to 93.29 % UGWM2 in week four. The ash was in the range 0.15 % in sample UGWM4 to 0.925 % in sample UGWM2 in week zero while it ranged from 0.17 % in sample UGWM4 to 0.93 % in sample UGWM2 for week four. Low protein content was also observed in all the samples. Sample UGWM1 had the least carbohydrate in week zero with 1.325 % and to 2.23 % in week four. Sample UGWM4 on the other hand had the highest carbohydrate content of 7.63 % in week zero and 7.065 % in week four. The alcohol volume ranged from 6.0 to 11.5 % both in week zero and four. The sample UGWM1 has the least pH value of 1.93 both in week zero and four while sample UGWM5 had the highest with 2.405. The titratable acidity was in the range of 0.225 mg/ml to 0.41 mg/ml. The results of the four weeks showed that the pH and titratable acidity of the formulated table wine were relatively stable.