Low-temperature Fresh-keeping and Processing Technology for Edible Mushrooms

Once fresh mushrooms are harvested, they must be arranged neatly in small, low-profile containers and sent to a low-temperature workshop as soon as possible for sorting. The container dimensions are length x width x height (the same below) = (40 x 28 x 16) cm, shaped like a turnover box, with a solid bottom panel, round holes of about 2-3 cm in diameter pre-set around the sides, and inset interlocking corner blocks at all four bottom corners to facilitate stacking in multiple layers. When harvesting, arrange the fresh mushrooms in the same direction, without letting heads and tails meet, to avoid contamination; the temperature in the low-temperature workshop is 1 degC-3 degC, and an ordinary constant-temperature cold storage room can be renovated for this use, with all other packaging containers also stored in the workshop to ensure thorough cooling. After the fresh mushrooms are moved into the workshop in boxes, place them separately and do not stack them in multiple layers again, so that the mushroom bodies can cool thoroughly; this step is especially important for fresh mushrooms harvested when the temperature is above 15 degC. The sorting tools are: a thin-bladed stainless steel knife or bamboo blade, as well as equipment for small-package sealing and box forming.

First use a small knife to trim the base of the fresh mushrooms clean, removing all soil, substrate and other debris; when there are many scales, remove them as well. Generally do not wash with water, otherwise the shelf life of the product will be shortened. Then immediately grade the clean fresh mushrooms and place them in containers lined with soft foam material, and package them after they have cooled thoroughly.

Cooling and packaging: Once the interior of the mushroom bodies has cooled to below 3 degC, they can be portioned for packaging. Generally, foam lunchbox-style containers can be used, made into single boxes about 5 cm high, each holding about 150 g of fresh mushrooms. Some large cities have banned the sale of plastic packaging, so custom paper boxes can be used. The specifications of the packaging box can also be determined according to the variety of fresh mushrooms; for example, shaggy ink cap mushrooms are generally suitable for packaging of 16 x 10 x 4 cm, Agaricus blazei is suitable for 15 x 10 x 6 specifications, and Hypsizygus marmoreus, willow mushroom, etc. are suitable for 16 x 8 x 4 specifications. The arrangement method is then determined according to the morphology and size of the fresh mushrooms. Then seal the package with cling film. Place the small packaging boxes into foam fresh-keeping boxes, each box can hold 36 boxes, and seal with transparent tape.

Boxing and transport: Because the fresh-keeping box has excellent insulation, and the boxed packaging inside has also been treated at low temperature, the fresh mushrooms will not decline in quality due to rising temperature within 5-12 hours: among them, shaggy ink cap mushrooms and straw mushrooms are the most difficult to keep fresh, but within 5 hours there will also be no quality decline.

Entering the supermarket: After entering the supermarket, the small packages should be placed in a low-temperature display cabinet for sale. Generally, the shelf life for sale can reach 2-10 days.