Microwave swelling of yam slice

Yam tuber mainly contains starch, polysaccharides (including mucus and glycoprotein), free amino acids and other nutrients. In addition, it also contains active components such as mucus, among which the amino acid composition of mucin is comprehensive and the essential amino acid content of human body is high. Chinese yam contains a lot of polysaccharides, so it shows good regulation or enhancement of immune function, antioxidant, anti-aging and anti-tumor function and hypoglycemic function.

Chinese yam is one of the specialties of jiaozuo. Mr. Zhao runs a Chinese yam deep processing enterprise, which mainly produces Chinese yam crisp chips. Before the fried way is very unhealthy, he want to try to use microwave equipment to make the puffed yam crisp.

Compared with the traditional puffing technology, the processing time of microwave puffing is short, which can preserve the nutrient components of the materials to the greatest extent, and overcome the shortcomings of traditional frying puffing, such as high oil content and high energy consumption.

Experiments are conducted with 20 kw tunnel microwave equipment and yam to clean peeled and cut into 3 different thickness (1.5 mm, 2.5 mm and 4.0 mm) of the chip, the blanching (70 ~ 80 ℃, 2 ~ 3 min), 3% sodium chloride solution soak 5 min, drain on the surface of the water, put in oven drying (temperature 70 ℃, 90 min), the embrittlement and chromaticity of the product were measured after drying for 50 s.

The microwave power of the processed samples was adjusted to 630 W for expansion of 10, 20, 30, 40, 50 and 60 s. Expanded 20, 30, 40, 50, 60, 70 s at 560W power; Expand 30, 40, 50, 60, 70, 80 s at 490 W power; Expand 40, 50, 60, 70, 80, 90 s at 420W power; Expanded 50, 60, 70, 80, 90, 100 s at 350W power. The brittleness and chromaticity of the products were measured respectively.

When yam chip thickness of 1.5 mm, microwave power 420 w, yam expanded to 60 s, yam crisp tender value of 6.917, and the process conditions of yam chip moisture content of 0.44%, the obtained yam crisp sheet has full organization, precise and even stomata inside, non-sticky and no dry, crisp taste, golden color and no coking phenomenon, with the fragrance of yam.

When the microwave swelling power was the same, the longer the swelling time was, the fuller the swelling time was, and the better the swelling effect was. If the swelling time is too short, the product expansion rate is small, hard texture; If the puffing time is too long, the product is easy to coke paste, so the microwave power and time together to control. The principle of test design is: the larger the fire power, the shorter the swelling time, and the smaller the fire power, the longer the swelling time.

Microwave puffing can greatly reduce the moisture content of yam crisp chip, kill harmful bacteria, reduce the growth and reproduction of microorganisms, and is conducive to the preservation of products and the improvement of quality and flavor.

According to the customer’s output of 300kg per hour, recommend a 30kw air cooling equipment to the customer, which is equipped with digital frequency conversion power, precise adjustment of power, PLC control, and set up the processing data to realize automatic production.