What are the key points of mushroom preservation technology? Understand in one article

The main factors affecting mushroom preservation are as follows:

Temperature: the higher the temperature, the worse the mushroom preservation. 0-4°C is the suitable temperature for mushroom preservation. Apart from quick freezing, below 0°C easily causes freezing damage.

Water quality: when the iron or copper content in water exceeds 2 mg/L, the mushroom color darkens and turns brown, so iron and copper utensils and tools are prohibited.

Humidity: 95-100% is required. Below 90%, the color darkens, and the caps easily open and spoil.

Gas composition: an important cause of spoilage, which can be inhibited by sterilization and adjusting pH value.

Enzyme activity: polyphenol oxidase is the main cause of mushroom browning.

Therefore, mushrooms have the following five preservation methods:

Mushroom preservation methods include controlled atmosphere preservation, low-temperature preservation, radiation preservation and chemical preservative preservation, etc. Low-temperature combined with controlled atmosphere preservation has the best effect.

1. Controlled atmosphere preservation: using 0.05 mm thick PE bags treated by a special physical method, simple controlled atmosphere temperature preservation of mushrooms shows that by adopting simple controlled atmosphere storage, within 3-5 days they remain fresh and tender without opening their caps, basically without browning, and the water loss rate is less than 1%. At present, breathable plastic film bag packaging is used, maintaining 1% oxygen concentration and 10-15% carbon dioxide concentration inside the bag, which can keep mushrooms white and fresh for 4 days with good freshness.

2. Cold storage preservation: low temperature can keep mushrooms fresh and high-quality. During storage and transportation, maintaining a temperature of 0-3°C and a relative humidity of 90-95% is most suitable.

3. Quick-freezing preservation: within 30-40 minutes, quickly reduce mushrooms from normal temperature to -30 to -40°C; the center temperature of the frozen mushrooms should be -20°C, then store frozen at -18°C, which can maintain the original quality and flavor for a long time. The quick-freezing process is: raw material acceptance, washing, color protection, rinsing, manual grading, air extraction, blanching, first cooling, second cooling, quick freezing, fine selection, ice glazing, packaging, frozen storage, transportation.

4. Chemical preservative preservation: Antiseptic cleaning agents: 10-20 mg/L potassium sorbate and sodium benzoate; 20 mg/L sodium sulfite; 10 mg/L benlate; 5-10 mg/L carbendazim or thiophanate-methyl. Rinsing and whitening agents: 0.1-0.5% sodium metabisulfite rinsing for 5-6 minutes; 0.1-0.2% sodium metabisulfite plus 10 mg/L guanine solution. Anti-discoloration agents: soak in 0.01-0.1% dimethylamine succinamic acid for 10 minutes, take out and drain, place in a sterilized plastic bag and seal, and at 0-4°C they can be preserved for 6-8 days without discoloration; soak in 0.02-0.05% ascorbic acid solution for 10-20 minutes, with the total time not exceeding 4 hours; spraying stable chlorine dioxide on mushrooms both at fruiting and before harvest has a significant effect. In short, using a preservation liquid prepared from food additives mainly composed of ascorbic acid and citric acid, adding it to fresh mushrooms of equal weight that have been soaked in 0.25% metabisulfite solution for 10 [minutes] and then rinsed with clean water for 20-30 minutes and drained for storage, can not only solve the problem of spoilage during long-distance storage and transportation, but also bring economic benefits to processing manufacturers.

5. Brine preservation: immediately place blanched mushrooms into a 19 Baume food-grade salt solution for salting, add an appropriate amount of refined salt after several days, and continue to maintain the 19 Baume food-grade salt solution. After 4-6 days, once the portions, weight and pH are all stable, they can be sealed and preserved.