Effect of Different Preservatives on Nutritional, Sensory Qualities and Shelf life of Papaya Fruit Bar

Abstract

Papaya fruit is an excellent source of vitamin C, carotene, minerals and other nutrients. The fruits are susceptible to decay and spoilage due to their perishability. Therefore, proper preservation techniques need to be adapted to extend the shelf life of papaya fruits. Accordingly, a research was conducted to assess the effect of different food preservatives on the quality and shelf life of papaya fruit bars. Ripened papaya fruit pulp, sugar, citric acid and 5% corn flour mixture was heated to get the Total Soluble Solids (TSS) content of 50˚Brix. The pulp was cooled and 1000 ppm of three different preservatives such as sodium benzoate, potassium metabisulphite and potassium sorbate were added separately. The blend was spread into 2cm layer and dried in a solar oven at 50˚C for 20 hours. The dried pulp was cooled, cut into rectangular bars and stored in plastic boxes at 30˚C and 75-80% RH for 6 weeks. The fruit bars were subjected to nutritional and sensory evaluations at weekly intervals during storage. Nutritional analysis revealed that there was a declining trend in ascorbic acid, total soluble solid and total sugar and an increasing trend in titrable acidity during storage. Fruit bar treated with potassium metabisulphite showed high retention of nutritional parameters such as 0.64% titrable acidity, 51.8 mg/100g ascorbic acid, 10.1˚Brix as total soluble solid and 25.1% total sugar at the end of the storage period. Sensory evaluation showed that the papaya fruit bar preserved with potassium metabisulphite had the highest overall acceptability compared to other treatments. Based on the results of this study, papaya fruit bar could be preserved using 1000 ppm of potassium metabisulphite for period of 6 weeks without any significant changes in the quality attributes.