Chemical Preservation Methods and Key Techniques for Edible Mushrooms

Chemical preservation of mushrooms has the advantages of being simple, low in cost, and highly effective.

Sodium chloride (table salt) preservation: after trimming freshly picked oyster mushrooms, Phoenix mushrooms, and the like, soak them in 0.6% salt water for about 10 minutes, drain, 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 the mushroom bodies with a 0.15% sodium metabisulfite aqueous solution, turning the mushrooms while spraying so that the spray is evenly applied. 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. Before eating, rinse them with clean water.

Rice water film preservation: use the thin rice water left from cooking rice, add 1% soda ash or 5% baking soda, and cool to room temperature. Soak freshly picked mushrooms in the rice water alkaline solution, remove after 5 minutes, and place in a cool, dry place. At this point a thin film of rice water forms on the surface of the mushrooms, which can isolate air and keep them fresh for 3 days.

Ascorbic acid preservation: after harvesting enoki mushrooms, shiitake mushrooms, straw mushrooms, and the like, 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 solution preservation: prepare a mixed soaking solution with 0.2% sodium chloride plus 0.1% calcium chloride. Soak freshly harvested mushrooms in the mixed solution, cover with a bamboo steamer rack and add a weight so that 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 solution preservation: prepare a mixed preservation solution with 0.05% ascorbic acid and 0.02% citric acid, soak fresh mushrooms in the preservation solution for 10 to 20 minutes, remove and drain, and package and seal in plastic bags.

Daminozide (B9) preservation: Daminozide is a plant growth retardant. Soak fresh mushrooms in a 0.1% daminozide aqueous solution for 10 minutes, remove and drain, bag and seal, and preserve 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.

Medical stone preservation: place fresh straw mushrooms in a plastic box, submerge the mushrooms in medical 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 fairly good.