Optimization of Process parameters for Vacuum Drying of Ripe Jackfruit bulb (Artocarpus heterophyllus L.)

Abstract

Jackfruit is an underexploited fruit and commonly referred as poor man’s fruit. Jackfruit is rich in Vitamin A, B, C and minerals such as calcium and iron and is also having immense medicinal value. It is a rich source of carbohydrates, minerals, carboxylic acids and dietary fiber. Based on peroxidase test, catalase test, colour and texture attributes the steam blanching for 30 s was standardised as pre-treatment. This fruit is seasonal and the post harvest losses are as high as 30%. Therefore, there is a need to develop a suitable processing protocol to reduce losses and also to enhance the shelf life and to extend the availability of this precious bulb in a ready to eat form though out the year. The deseeded jackfruit bulb after the pretreatment was dried in a vacuum dryer at a fixed vacuum chamber pressure of 680 mm of Hg. The drying was done at temperatures of 25, ° ° 30, 35, 40 and 45 C. The vacuum chamber temperature of 40 C was standardized ° on the basis of quality parameters like pH, TSS ( Brix), vitamin C, colour, texture and rehydration ratio. The drying time required to reach a safe moisture content of ° 7.46 ± 0.27% (d.b) at 40 C was 10 h. Storage studies were conducted in 5 types of packaging materials such as polythene cover, LDPE 100, LDPE 300, LDPE 400 gauge and laminated aluminum foil with MAP of 30% O 2 + 50% CO 2 (with balance of N 2 ) gas mixtures. The quality of the stored product was assessed in ° terms of moisture content, pH, TSS ( Brix), vitamin C, colour, texture, rehydration ratio and also by microbial analysis in every 15 days interval. Sensory analysis was also conducted as traits and was done based on Kendall’s coefficient of concordance tests. At the end of 30 days LDPE 400 gauge resulted in less loss of quality parameters. ° So deseeded jackfruit bulbs, steam blanched at 100 C for 30 s followed by ° vacuum drying at 40 C at a fixed vacuum chamber pressure of 680 mm of Hg for 10 h. The dried product packed in 400 gauge LDPE films can be stored at room temperature for 30 days without any quality deterioration.