Effect of osmotic agents on quality and storability of osmo-dried plum

Abstract

Plum, a highly palatable fruit is perishable in nature, as it has very high moisture content. Hence it is being processed widely due to perfect blend of sugar and acid content in the fruit. Osmotic dehydration of the fruits by dipping in hypertonic solution is a convenient alternative for utilizing them as osmo-dried fruits. In order to enhance its shelf life, ripe fruits of Santa Rosa plums were treated with osmotic agents viz., sugar and honey (40, 50, 60 and 70% each) for the development of osmo-dried plum. After drying, osmo-dried plums were packed in low density polypropylene and stored for three months under ambient temperature (34-38°C). An increasing trend was recorded in TSS, reducing sugars, total sugars and non-enzymatic browning, however titratable acidity, dehydration ratio, rehydration ratio and total phenols tended to decline during the course of storage. The osmo-dried plum developed from 70° Brix honey syrup was found to be the best osmotic agent, based on overall acceptability followed by 60 °Brix honey syrup. Storability studies revealed that all the treatments could retain the osmo-dried fruits for 3 months without affecting the quality.