What are the chemical preservation methods for edible mushrooms?
Sodium chloride preservation: After trimming freshly picked oyster mushrooms, Phoenix-tail mushrooms (Pleurotus pulmonarius), and similar varieties, soak them in a 0.6% salt solution for about 10 minutes. Drain them and store in plastic bags; they can be kept fresh for 5 to 8 days.
Sodium metabisulfite preservation: Spread freshly harvested oyster mushrooms on a clean concrete floor and spray them with a 0.15% sodium metabisulfite aqueous solution, turning the mushrooms while spraying so they are evenly coated. After spraying, place them in plastic bags, seal immediately, and store in a cool place. At 10°C to 25°C, they can be kept fresh for 8 to 10 days. Rinse with clean water before eating.
Rice porridge film preservation: Use the thin rice porridge water from cooking rice, add 1% soda ash or 5% baking soda, and cool to room temperature. Soak freshly picked mushrooms in the alkaline rice porridge liquid for 5 minutes, then remove and place in a cool, dry place. At this point a thin film of rice porridge forms on the surface of the mushrooms, which can block air and keep them fresh for 3 days.
Ascorbic acid preservation: After harvesting enoki mushrooms (Flammulina velutipes), shiitake mushrooms (Lentinula edodes), straw mushrooms (Volvariella volvacea), and similar varieties, spray the fresh mushrooms with a 0.1% ascorbic acid solution and place them in a non-iron container. They can be kept fresh for 3 to 5 days, with their freshness and color basically unchanged.
Sodium chloride and calcium chloride mixed liquid preservation: Prepare a mixed soaking liquid with 0.2% sodium chloride plus 0.1% calcium chloride. Soak freshly harvested mushrooms in the mixed liquid, cover with a bamboo rack and place a weight on top so the mushrooms are submerged below the liquid surface for 30 minutes. At 15°C to 25°C they can be kept fresh for about 5 days, and at 5°C to 10°C for more than 10 days.
Ascorbic acid and citric acid mixed liquid preservation: Prepare a mixed preservation liquid with 0.05% ascorbic acid and 0.02% citric acid. Soak fresh mushrooms in the preservation liquid for 10 to 20 minutes, remove and drain, then pack and seal in plastic bags.
Daminozide preservation: Daminozide is a plant growth retardant. Soak fresh mushrooms in a 0.1% daminozide aqueous solution for 10 minutes, remove and drain, then bag and seal. Stored at 5°C to 25°C, they can be kept fresh for more than 15 days. It is suitable for preserving mushrooms such as button mushrooms, shiitake mushrooms, oyster mushrooms, and enoki mushrooms.
Maifan stone preservation: Place fresh straw mushrooms (Volvariella volvacea) in a plastic box, submerge the mushrooms in Maifan stone water, and keep them fresh at a low temperature below 0°C. The preservation period can reach 70 days. Moreover, the amino acid content differs little from that of fresh mushrooms, and the color and taste are both good.