Several problems needing attention in fresh-keeping mushroom export processing

I. selection of raw materials

In the processing of fresh Lentinus edodes, we should first pay attention to the freshness of raw materials, which is an important factor to determine the quality of fresh Lentinus edodes products. The raw materials should be fresh and the color should be normal; secondly, the mushroom shape should be complete and round, the mushroom stalk should be intact, and the mushroom body should maintain the beautiful shape of natural growth; the mushroom meat should be thick, the edge of the mushroom cover should be rolled in neatly, the bacterial film should be broken or slightly opened, and the umbrella should not be opened; the diameter of the mushroom cover should not be less than 38mm; there are no diseases and insect pests, odors and soil impurities.

II. Raw material handling and cold storage

First of all, the raw materials should be precooled and dehumidified. In order to maintain the good freshness and color of raw materials, fresh mushrooms should be pre-cooled and cooled in time after picking. According to the performance of the equipment and the water content of fresh mushrooms, grasp the appropriate pre-cooling temperature and appropriate dewatering rate, through pre-cooling to drain moisture to meet the export requirements. If the blast cooling method is adopted, the cold storage temperature is controlled between 1 ℃-3 ℃, and the center temperature of fresh mushrooms is 2 ℃-4 ℃, so that the water content of fresh mushrooms is reduced to 75% 80%. At room temperature, it is not suitable to use the method of ventilating, cool and draining moisture or spreading in the sun.

Secondly, the classification and selection of raw materials. According to the requirements of foreign trade customers, usually according to the mushroom cover diameter size of the classification screen made of white iron for screening or manual visual separation. The classification usually adopts a three-stage system: the diameter of the lid of the large mushroom (L) is more than 55mm, the diameter of the lid of the intermediate mushroom (M) is between 45 and 55mm, and the diameter of the lid of the minor mushroom (S) is between 38 and 45mm. While classifying the raw materials, the damaged, detached, discolored, spotted, deformed and unqualified inferior mushrooms should be removed, and should be refrigerated in time after selection. Conditional areas can be graded and selected in cold storage to ensure the good quality of fresh mushrooms.

Thirdly, keep it fresh in cold storage. During the period of cold storage, the temperature of cold storage directly affects the quality of finished products of fresh mushrooms. therefore, the temperature of cold storage is very important in the process of cold storage. If the cold storage temperature is higher than 5 ℃, fresh mushrooms can continue to metabolize, resulting in decreased freshness, aging tissue and finally opening umbrellas; if the cold storage temperature is lower than 0 ℃, fresh mushrooms are vulnerable to freezing damage, softening and eventually water-like decay and deterioration, even inedible. Therefore, the cold storage temperature during cold storage must be strictly controlled between 1 ℃-3 ℃.

III. Packaging and Transportation

The packaging of fresh Lentinus edodes is different from that of other products. In order to ensure the quality of fresh mushrooms, packaging materials and containers should not only be hygienic and non-toxic, but also should be heat-insulated and impervious, not affected by the external environment, have strong cold preservation performance in a certain period of time, and can make fresh mushrooms in a good state of low temperature.

The packaging container of fresh-keeping Lentinus edodes is generally a covered rectangular plastic box made of foam die-casting, and there is a raised ridge around the lid, which closely coincides with the mouth of the box. After loading the mushrooms, seal it with transparent tape around the mouth of the box.

The packaging of fresh mushrooms must be carried out in a low temperature room with no peculiar smell and no higher than 3 ℃. Packaging utensils and staff uniforms should be kept clean and disinfected regularly. Non-staff members are not allowed to enter or leave the packaging place at will to prevent the rise of storage temperature and the transmission of germs and sundries to pollute products.

Packing must be carried out before the date of export is determined. First of all, cut the fresh mushroom stalk, leaving a length of about 25 cm, while cutting the mushroom stalk while packing, if the mushroom stalk is cut too early, the shearing of the mushroom stalk will oxidize and brown and affect the appearance. The fresh mushrooms are packed in plastic film bags filled with the same grade Lentinus edodes, vacuum and then packed into a foam box, the mouth of the box is sealed and covered with double corrugated cartons, and the mouth of the carton is filled with viscose tape.

There are also cases where Lentinus edodes are packed in small packages. Small packaging is usually made of foam plastic bags into small trays, each plate of fresh mushrooms neatly arranged, some fold outward, wrapped with a layer of fresh-keeping film sealed airtight or pumped into a vacuum, and then packed into a carton with adhesive tape at the mouth. When the packing is finished, mark it and wait for shipment.

Fresh Lentinus edodes should be shipped in time after packaging. fresh mushrooms transported from the origin to the port must be transported by refrigerated trucks and strictly controlled to prevent the temperature from rising so as to ensure the quality of fresh mushrooms.

IV. Several problems that should be paid attention to in production

Most of the fresh-keeping Lentinus edodes belong to artificial sawdust Lentinus edodes rather than log Lentinus edodes. In order to restrain the harm of miscellaneous bacteria in production, carbendazim or other fungicides are usually mixed into the nutrients of cultivated Lentinus edodes to prevent mildew and sterilization, and the dosage should be strictly limited to the lowest range of safety to the human body. During the cultivation and production of Lentinus edodes, a large amount of water must be sprayed every day. The water quality must be clean and must not contain microorganisms and metal substances that are harmful to the human body to ensure the cleanliness and hygiene of fresh mushrooms. Lentinus edodes, like other mushrooms, contains a lot of water, which is more than 90%. In order to maintain the quality of finished products and shorten the time of dehumidification, it is forbidden to spray water the day before picking fresh mushrooms.