Lime potentials as biopreservative as alternative to chemical preservatives in pineapple, orange and watermelon juice blend
The major challenge influencing fruits economic value is the relatively short shelf-life. This study preserved fruit juice blend from pineapple, watermelon and orange using lime juice as biopreservative comparing its effectiveness with ascorbic acid and citric acid as chemical preservatives during storage at ambient temperature (27±2oC) for five weeks. The acceptability of the juice by consumer, biochemical changes and microbial load was also evaluated on a weekly basis. From the results, all the samples were acceptable on a 9-point hedonic scale (8.70-8.90) with 1% lime biopreserved juice blend was the most preferred. This shows that that lime effectively controlled the rate at which increase pH and decrease of TTA occurred during storage by double-fold when compared with ascorbic and citric acid used in the study. A minimal decrease in pH of 0.75% was documented during the five weeks of study. The specific gravity of the juice was relatively table during storage except for the unpreserved juice. Lime addition at 2 and 4% effectively suppressed fungal growth in the juice for five weeks of storage. Lime juice added as biopreservative at 4% showed the best bacteriostatic and fungistatic performance while the consistent increase in the bacteria growth from 60×102 - 11×1010 CFU/mL was recorded in unpreserved at ambient temperatures during storage. Ascorbic acid and citric acid as preservative effectively inhibited microbial growth of bacterial and fungal for 2 weeks, followed by a steady increase from 16×101 - 17×103 , 20×102 - 62×102 and 20×102 - 36×104 ; 21×102 - 48×102 CFU/mL respectively. Low Bacterial count was recorded in juice preserved with 1% lime (70×101 CFU/mL), 2% lime preserved (41×102 CFU/mL) and 4% lime (13×101 CFU/mL) at week 4 and week 5 respectively. The study established that lime is a good biopreservative with antimicrobial effect can serve as a replacement for chemical preservatives.