Processing and shelf-life assessment of mixed-fruit juice from pineapple, orange, paw-paw and guava

Mixed fruit juice was produced with pineapple (40%), orange (30%), pawpaw( 20%) and guava (10%). Different samples of the product were treated (preserved) with different levels (0.04%, 0.06%and 0.08%) of sodiumbenzoate, pasteurized and stored on ambient shelf for three months. pH, titratable acidity, soluble solids, ascorbic acid and total microbial count were analyzed on the fresh and stored samples at one and three months. pH of all the samples significantly (P u003c0.05) decreased with added benzoate during storage. Titratable acidity for the samples increased after three months. Total soluble solids (brix) decreased with storage and addition of benzoate but insignificantly, while brix/acid ratio significantly decreased with added benzoate and storage period from 18.60 (in fresh sample) to 16.13 (after three months); 16.0 to 13.86 and 15.40 to 12.73 for samples with 0.04%, 0.06%and 0.08%benzoate respectively.Ascorbic acid content also showed significant decrease in all samples, and sample preserved with 0.8% benzoate retained highest ascorbic acid content and lowest microbial count (Saccharomyces cerevisiae and Lactobacillus species) after 3 months storage. Staphylococcus aureus and Penicillum species were identified in the control and 0.04%-benzoate-preserved samples. Overall acceptability result between the fresh and stored samples showed insignificant difference.