Method for drying mushroom by combining ultrasound and hot air and ultrasound wave irradiation device

Abstract

The invention discloses a method for drying a mushroom by combining ultrasound and hot air and an ultrasound wave irradiation device. The method comprises the following steps: 1) pretreating mushroom raw materials; and 2) drying by combining the ultrasound and the hot air: putting the mushroom onto a screen, starting a heating blower device and the ultrasound wave irradiation device in sequence so as to conduct drying by combining the ultrasound and the hot air to the mushroom, wherein drying temperature is 40-70 DEG C, drying wind speed is 0.5-3 m / s, ultrasonic power is 50-200 W, ultrasonic frequency is 18-25 kHz, the distance from the ultrasound wave irradiation device to the screen is 5-20 cm, and drying time is 1-8 h. By means of the method for drying the mushroom by combining the ultrasound and the hot air, heat transfer efficiency and mass transfer efficiency in the drying process are improved, the drying time is shortened, and energy consumption is saved. The mushroom dried according to the method is good in appearance and color, small in percentage of contraction, good in rehydration performance and strong in smell specific to mushrooms.

Description

Technical field [0001] The invention belongs to the technical field of agricultural products processing, and specifically relates to a method for drying shiitake mushrooms by ultrasonic combined with hot air and an ultrasonic irradiation device. Background technique [0002] Shiitake mushroom is the world's second largest edible fungus. It has a delicious taste, refreshing aroma, and rich nutrition. It is rich in vitamin B complex, iron, potassium, and provitamin D. It is a high-protein, low-fat nutritious health food. Among the processing methods of shiitake mushrooms, drying is the most common method. Drying processing is to use the low water activity of the product to inhibit the growth and reproduction of microorganisms and enzyme activity, while giving the product a good flavor, achieving the purpose of long-term storage, easy transportation, and consumption. [0003] As a major drying technology, hot air drying is widely used in food, especially in the production of dehydrat...

AI Technical Summary

Problems solved by technology

However, it cannot be ignored that hot air drying also has some problems that need to be solved urgently, including: low heat and mass transfer efficiency, long drying time, high energy consumption, and low product quality

In order to improve the efficiency of hot air drying, it usually needs to be carried out at a higher drying temperature, which is very unfavorable to many heat-sensitive ingredients and physiologically active ingredients in food, and will easily lead to a decline in product quality, such as: loss of nutrients and aromatic substances, loss of functional ingredients Deactivation, surface hardening cracking, excessive shrinkage, low rehydration and noticeable color change; additionally significantly increases energy consumption

At the same time, the longer hot air drying process can easily cause the growth and reproduction of microorganisms, especially food spoilage.

Due to the above reasons, the use of hot air drying technology to dry shiitake mushrooms also has the following problems: 1) If the drying time is too long, the caps of shiitake mushrooms will be deformed and unrounded, the gills will be inverted, the caps will be cracked, and the color will turn black, which will destroy the activity of the enzyme , so that mushrooms lose their unique aroma and taste; 2) high energy consumption

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