Effect of storage and Preservatives on Antioxidant Status of some Refrigerated Fruit Juices

Limiting or preventing the growth of undesirable microbial flora in food products is one of the main goals of food preservation. A number of preservation methods have been designed to extend the shelf-life of the food products, not only by reducing the microbial growth, but also to maintain the antioxidant potential to serve the consumers needs. The aim of the present study was to compare the changes in the contents of antioxidant biomolecules like total flavonoids, total polyphenols and ascorbic acid of seven fruit juices available in local markets of Kolkata, before and after storage in refrigerated conditions. Effect of sodium benzoate as preservative was also adjudicated during storage. It was observed that the flavonoids content, total phenol contents and ascorbic acid contents of the fruit juices have been deteriorated after 10 days of refrigeration if no preservative was added. However, the juices retained some of their bioactives on addition of the preservative, even after 10 days refrigeration. Retention of flavonoids and phenolics indicated that sodium benzoate might not only inhibiting microbial growth, but also scavenged free radicals generated due to oxidation over time. The study indicated a plausible way of preserving commercial fruit drinks during refrigerated storage.