Extraction and characterization of natural enzymes from bottle gourd ( Lagenaria siceraria ) and effect of enzyme inhibitors in extending the shelf life of bottle gourd cut pieces

Fresh-cut fruits and vegetables are one of the widely consumed commodities in grocery stores. Fruits and vegetables on trimming lose their natural protection leading to browning and other undesirable changes. In this study, a novel method following minimal processing concept with hurdle technology was formulated to improve the shelf life of fresh-cut bottle gourd. Characterisation of the bottle gourd extract revealed the presence of indigenous enzymes xylanase, pectinase, and amylase. Since these enzymes cause spoilage, a pre-treatment of bottle gourd slices using different combinations of EDTA, CaCl2, sodium metabisulphite (SMS) and citric acid was studied to inhibit the enzyme activity. Pre-treatment using a combination of 1 mM EDTA, 2.5% CaCl2, 2% Sodium metabisulphite (SMS) and 0.5% Citric acid inhibited the enzymes efficiently. Further, to prevent the water leaching during storage, the fruit slices were fed to a partial dehydration (30%) process. The hurdle technology, chemical pre-treatment followed by partial dehydration, helped the cut-bottle gourd pieces to stay acceptable in terms of titrable acidity, total solids, texture, color, and microbial quality for 20 days at 4 °C.