Matters needing attention in the processing of Lentinus edodes

Lentinus edodes is known as Shanzhen, with rich nutrition and delicious taste. Its dried products (commonly known as dried mushrooms) can be divided into flower mushrooms, winter mushrooms, thick mushrooms and thin mushrooms. However, due to the lack of drying technology at present, dried Lentinus edodes products have some problems, such as poor color, light flavor, unbeautiful mushroom shape and so on, which seriously affect the commodity value. If Lentinus edodes is well processed, its value can be nearly doubled. Let's talk about the key technologies of the processing methods of dried Lentinus edodes.

1. Sun-drying method

Stop spraying water on Lentinus edodes 2 days before harvest, and choose sunny weather when Flower mushroom and thick mushroom 5-7 mature (partial rupture of bacterial membrane), or mushroom 7-8 mature (bacterial membrane has been broken, the cover is not fully unfolded, a few inner rolls and pleats have been elongated, and changed from white to yellowish brown or dark brown). Hold the base of the mushroom handle with your hands and rotate the mushroom body lightly. After harvesting, the fresh mushrooms are graded according to their size and thickness, and are spread out on the sun screen with the handle down (the screen can be lined with a sunshade net to absorb more heat). The sun screen is tilted to the ground at an angle of 30 °, the slope faces the sun, receives direct sunlight, and adjusts the screen orientation with the movement of the sun. Fresh mushrooms can be dried in 3-5 sunny days. The shorter the drying time, the better the quality of dried mushrooms. At this time, the water content of Lentinus edodes is about 20%, which is still higher than the standard water content of dried mushrooms below 13%, and the flavor of Lentinus edodes must be baked at a temperature of more than 50 ℃ before it can be produced. Therefore, drying fresh mushrooms until semi-dry and then forced dehydration with hot air is a more economical and effective method in the drying of Lentinus edodes.

2. Drying method

The performance of the drying equipment must meet the requirements of the drying and dehydration process of Lentinus edodes, and the temperature and flow rate of drying air can be adjusted according to the needs of the process. At present, the drying oven is mainly used as the drying equipment of Lentinus edodes. The fresh mushrooms harvested should be arranged in time and moved into the oven within 3-4 hours. According to the size and thickness of mushrooms and the classification of open umbrellas and non-open umbrellas, the folds are uniformly arranged upward or downward uniformly and neatly, with large, wet and thick shiitake mushrooms in the middle of the sieve, small mushrooms and thin mushrooms on the upper layer, and poor quality mushrooms and stalks on the bottom.

The whole drying process is divided into four stages:

⑴ was prepared in the drying stage. That is, Lentinus edodes has just entered the crude dehydration stage, the temperature should be controlled at 30-50 ℃, and the moisture should be reduced to 75%. The initial temperature of Lentinus edodes harvested in sunny days is 40 ℃ and the crude dehydration time is 3-4 hours, while the initial temperature and crude dehydration time of Lentinus edodes harvested in rainy days are 30 ℃ and 4-5 hours respectively. In this period, due to the high humidity of Lentinus edodes, the cell has not yet been killed, the temperature should not be lower than 35 ℃ for a long time, and the air inlet and outlet should be opened to discharge moisture as soon as possible, and the temperature will rise evenly, rising 1-2 ℃ per hour.

⑵ drying stage. The moisture of the fruiting body continues to evaporate, and gradually enters the hardened state, the shape tends to be fixed, and the degree of dryness is about 80%. The temperature rises slowly and evenly from 50 ℃ to 55 ℃, which takes 8-10 hours. At this stage, the air inlet and outlet should be adjusted.

⑶ post-drying stage, also known as setting stage. The water evaporation rate of Lentinus edodes slows down, and the body of Lentinus edodes begins to harden, which plays a decisive role in the shape of dried mushrooms. The temperature is kept at 55 ℃ for 3-4 hours.

⑷ completion phase. The temperature in the oven rises from 55 ℃ to 60 ℃ and can kill the eggs for about 1 hour until the internal humidity of Lentinus edodes is the same as the surface humidity, the water content is 11-13%, the color is smooth, and the drying is complete.

Matters needing attention:

⑴ fresh mushrooms can not be stacked, so as not to affect the drying rate of Lentinus edodes and the uniformity of dehydration between mushrooms.

⑵ drying should be carried out in sunny days, and the air relative humidity is low in sunny days, which is helpful to reduce the drying time.

⑶ drying procedure should be set according to different conditions of fresh mushrooms. If the folds of Pleurotus ostreatus and Pleurotus ostreatus are often lodging, this kind of mushroom can be pre-dried in the sun (until the cover is shiny and the fold stands up), and then transferred to the conventional drying treatment.

⑷ strictly controls the drying temperature of each stage. When the temperature is low, the folds of dried mushrooms turn white; if the temperature is too high, the folds are too yellow or scorched yellow. The temperature should not be high or low during the drying process, otherwise the surface of dried mushrooms will not be glossy.

⑸ dried mushrooms should be bagged after returning to moisture properly. Bagging immediately after drying will affect the appearance of dried mushrooms. Dried mushrooms should be bagged after proper moisture regain, and should also be prevented from crushing during storage.