Preservative Potentials of June Plum Extract on Watermelon Juice (Citrullus spp.)

Abstract

Background and Objective: Microorganisms spoil food and beverages, reducing quality and posing health risks. To extend shelf life, different methods like refrigeration, pasteurization and preservatives are used. This research aimed to evaluate the potential of June plum derived from citric acid as a natural preservative for extending the shelf life of watermelon juice. Materials and Methods: The experiments were designed using a Box-Behnken experimental design within the framework of response surface methodology. The measured parameters were total viable count, total coliform count, total fungi count, pH and titratable acidity over a 28-day storage period. The watermelon juice was prepared and pasteurized, while citric acid was extracted from June plum. The Independent variables were citric acid concentration (0.5-10 g), pasteurization time (10-20 sec) and storage temperature (0-30°C). Results: Total viable count, total coliform count, total fungi count over 28 days ranged from 2.60 (Day 7) -4.45 (day 28) CFU/mL, 0 (day 7) -378 (day 28) CFU/mL, 0.02 (day 7) -1.17 (day 28) CFU/mL: pH over 28 days ranged from 4.10 (day 0) -3.53 (day 28). The titratable acidity ranged from 0.82-2.79 over 28 days. The study established that the total viable count, total coliform count and total fungi count remained within acceptable limits for up to 28 days when the fruit juice was preserved with citric acid and stored at 0, 15 and 30°C. Conclusion: The study showed that the application of June plum derived from citric acid, along with controlled pasteurization time and storage temperature, effectively inhibited microbial growth and maintained the quality of watermelon juice over a 28-day period.