What is the mechanical drying process of konjac? What problems should be paid attention to in production?

Mechanized production technology of dry konjak: fresh konjak bulbs → digging out main buds → cleaning and peeling → slicing (slices or strips) → color protection → drying → inspection → packaging → finished products.

The following points should be noted in production:

(1) Remove the bud nest

At present, this process is not mechanized, and the skin and buds of the bud nest need to be dug by hand. If you don't dig thoroughly, the fine powder will have black spots.

(2) Cleaning and peeling

Sediment and other sundries attached to the surface of the bulb should be cleaned up. The surface of konjac is periderm, which contains no glucomannan and should be removed. The traditional method is manual scraping and cleaning, which is inefficient and labor intensive. At present, mechanized cleaning and peeling have been adopted, and the production efficiency is high. However, due to the unplanned shape of fresh taro bulbs, the peeling of protruding parts is often excessive, and the peeling of concave parts is not enough. In addition, in the process of kneading, part of glucomannan is dissolved, and the loss of washing and peeling is sometimes as high as 65,438+05%. Therefore, it is necessary to choose a suitable model, determine reasonable mechanical working parameters, or combine mechanical cleaning with manual cleaning to reduce losses and improve cleaning and peeling quality.

(3) Slice (or strip)

Fresh taro after cleaning and peeling should be cut into pieces or strips with uniform size in time for drying. One specification is to cut into strips with a width of 2.5 cm and a thickness of 3 ~ 4 mm, and the other specification is to cut into pieces with a thickness of 5 ~ 10 mm.

(4) color protection

Bulbs are easy to change color after peeling and slicing, and color protection should be carried out immediately after slicing. The color protection of konjac is mainly carried out by high temperature passivation enzyme and fuming sulfur dioxide. Pay attention to controlling sulfur dioxide when smoking, and it is better that sulfur dioxide at least achieves color protection effect.

(5) drying

At present, mesh bag, vibrating fluidized bed or vibrating fluidized bed combined with mesh bag are the main drying methods, and the drying process is divided into two stages: high temperature sulfur fumigation and color fixation and low temperature drying. Generally, the hot air temperature is 1 10 ~ 130℃ in the high temperature section, 50 ~ 70℃ in the low temperature section and 40 ~ 50℃ in the bag outlet. The general trend of temperature is from high to low, and sulfur fumigation has also changed from the whole process of sulfur fumigation in the past to the early sulfur fumigation. The drying process mainly needs the comprehensive coordination of boiler workers, technicians and production teams to obtain high-quality dry konjac with white color and dry body.

(6) Quality inspection

After weighing, crushing and drying, the water content of taro chips can be measured or judged by experience. It is usually crushed with a heavy object or a hammer. If it is crushed, it is dry, otherwise the moisture content is high. Sample comparison method can also be used to compare with samples with known accurate moisture content. Color can be judged by senses, burnt slices of dried taro slices, black heart rate and cleanliness. In actual production, inspectors mainly use water content and premium rate as the main basis for scoring.

(7) packaging

In order to prevent moisture and pollution, the dried taro chips after inspection should generally be moisture-proof packaged. In production practice, most manufacturers adopt the method of processing raw materials into konjac powder as soon as possible to facilitate moisture-proof packaging.