Evaluation of different polymeric films for extending shelf life of Volvariella volvacea, the paddy straw mushroom

Shelf life studies of freshly harvested mushrooms of Volvariella volvacea (Bull ex Fr.) strain VV-11 was carried out using 0.1% KMS washed fruit bodies packed in punnet trays overwrapped with different polymeric films (Impact, RD 106, cling film and low density polyethylene). Polypropylene (PP) bags were used as control. Packs were stored at ambient room temperature (25–32°C) for 3 days showed upto 28.1% weight loss after 3 days of storage and minimum loss was in cling film packs (5.2 - 23.8%). The fruit bodies overwrapped with cling film retained more whiteness on 3^rd day with L-value of 69.8 for KMS washed fruit bodies. Statistically lower L-value (63.9) was observed for KMS washed fruit bodies packed in PP bags. Cling film also showed minimum increase in CO₂ concentration during the three days of storage followed by RD106 and Impact films. In control PP bags, CO₂ concentrations increased up to 17.6% after 3 days which was significantly higher than the other polymeric films evaluated. The microbial load increased from log 5.0 cfu/g with time in all the samples and was not statistically different among the different films tested. The lowest polyphenol oxidase (PPO) activity was on zero day (0.09 U/min/g) which increased to (0.15 U/min/g) by 3^rd day of storage. Cling film packed fruit bodies retained best nutritional attributes of the fruit bodies during storage. The effect of different storage temperatures (10, 15 and 30°C) on the various physical, nutrient and biochemical parameters of 0.1% KMS washed fruit bodies packed using cling film showed that all the parameters were better retained upto 3^rd day of storage at 15°C.