SHELF-LIFE EXTENSION OF PEELED ORANGES BY CITRIC-ACID TREATMENT

The microbial spoilage of peeled oranges was caused predominantly by G ram negative bacteria Enterobacter agglomerans, and Pseudomonas spp., end yeasts Cryptococcus albidus, Rhodotorula glutinis, and Saccharomyc es cerevisiae. infusion of fruits with citric acid solution (0.1, 0.25 , 0.5, and 1.0% w/v) during the peeling process reduced the surface pH of peeled fruits (from 6.0 to <4.6) and extended their shelf life in comparison with fruits infused with water only. Regardless of treatmen t method (dipping or infusion), maximal shelf life extension was attai ned with 0.5% w/v citric acid for 4 degrees C storage or 1.0% w/v citr ic acid for 8 and 21 degrees C storage. Infusion of 0.5% w/v citric ac id extended shelf life of both peeled whole and chunked fruits. The ex tension of shelf life resulted primarily from the inhibition of spoila ge bacteria. (C) 1997 Academic Press Limited.