Polysaccharide composite formulations for coating and film applications in cold-storage preservation of Agaricus bisporus: a comparative performance study

Mushrooms spoil rapidly due to high moisture, active enzymes, and microbial vulnerability. To address this, researchers tested composite of coating and filming types on fresh mushrooms: four edible coats made from carboxymethyl cellulose (CMC), carrageenan, purple yam starch, or chitosan, and four film blends containing agar, almond gum, nanoclay, rice protein, garlic peel, and garlic pod extract. Storage trials ran for 15 days at both refrigeration (4 °C) and room temperature (28 °C), with assessments every 2 days. Coated mushrooms consistently showed lower weight loss (12–80% less than uncoated ones), with CMC and purple yam starch giving the best moisture retention. Nanoclay–rice protein films also proved effective. Cold conditions preserved color, firmness, and pH, while warm storage triggered enzymatic browning through rising polyphenol oxidase (PPO) and peroxidase (POD) activities and dropping ascorbic acid. Although vitamin C declined over time due to oxidation, total phenolics and antioxidant capacity increased, likely from stress-induced release of bound compounds. Microbial growth—mold and bacteria—was evident on uncoated mushrooms, whereas chitosan and nanocomposite coatings suppressed it effectively. The best overall preservation came from CMC–purple yam starch and nanocomposite films kept at 4 °C. Across all samples, weight loss spanned 12% to 80%, with rice protein and chitosan minimizing losses most. Color retention was strongest with purple yam starch, CMC, and carrageenan. PPO activity (15–37 U g −1 min −1 ) declined in coated groups, signaling reduced browning, and POD also decreased, particularly in cold storage. pH stayed stable between 5.8 and 6.3, best maintained by CMC and purple yam starch coatings. Among all treatments, F3 (CMC, carrageenan, and purple yam starch) performed best under refrigeration, while room-temperature samples deteriorated faster. These results confirm that polysaccharide-based coatings offer a biodegradable, effective alternative to synthetic packaging for prolonging mushroom freshness.