Sample preparation
Lotus roots were washed with running water, dipped into chlorinated water (7500 ppm active chlorine) for 5 min and dried at room temperature with forced air. Then they were peeled and cut into about 4 mm thick slices using a sharp knife. Three different treatments were used: (1) uncoated, (2) uncoated + MAP, and (3) coated + MAP. For treatments (1) and (2), lotus root slices dipped into sterilized distilled water for 5 min. For treatment (3), lotus root slices dipped into chitosan-based edible coating solution for 5 min. Treated samples were kept over a plastic sieve for 50 min and a fan generating low speed air was used to hasten drying. The excess solution on the surface was absorbed by a tissue paper. 100 g of untreated and treated lotus root slices was packaged in trays (150 × 150 mm) and sealed with a micro-perforated polyethylene (30 μm thickness). Changes in CO2 and O2 concentrations in packages were measured using a Checkpoint O2/CO2 meter (PBI-Dansensor A/S, Danish). The samples were stored at 4 °C for 10 days and color, PPO activity, MDA content and overall visual quality were measured at one-day intervals.