Production and Shelf-Life Extension of Grape Juice Sweetened with Honey and Preserved with Ginger - Abstract
Grape fruit juice was processed with different concentrations of honey and ginger and physicochemical, nutritional and microbial quality of the juice was investigated. Samples (T2, T3, T4, T5 and T6) were processed with some levels of honey and ginger whereas T1 and T7 served as control. The results of the analysis showed that there was a significant difference (P<0.05) in the protein content. The percentage moisture content (91.47- 94.76%), carbohydrate (3.06 -6.71%), Crude fibre (0.18 -0.78%), fat (0.13 -0.29%) and ash content (0.45 -0.84%) recorded some level of difference on the juice samples (P<0.05). The physicochemical results showed that there was no significant different in the pH, specific gravity, titratable acidity on the sixth day whereas significant difference was observed on the sugar content. There was no significant difference on vitamins B1 , B2 and B3 on eachday of analysis but differences exist between 1st, 3rd and 6th day respectively. Vit C showed a level of difference significantly (P<0.05). Sensory scores show that samples 513, 417 and 283 were more preferred than other samples. Results of microbial analysis showed that microbial growth at the 1st day (1.8 x 104 -3.8x 104) cfu/ml increased slightly during the 3rd day of juice storage (2.7 x 104 – 5.8 x 104) cfu/ml. The load of microorganisms increased during the sixth day (6.3 x 104-10.2 x 104 cfu/ml). Samples without ginger (T1 and T7) recorded the highest microbial growth and juice deterioration. All samples with different concentrations of ginger and honey recorded lesser level of deterioration. Samples with highest concentration of ginger (2%) and honey (2%) preserved more than others. This study show that ginger has antioxidative and anti-microbial properties capable of prolonging the shelf life of processed grape fruit juice.