Study On The Mechanism Of Microwave Shelling Of Chinese Chestnut And Its Processing Technique

Chinese Chestnut is a special kind of dried fruit in China, high quality and rich in nutrition, and is the important export products as well. At present, the Chinese Chestnut processing technology is not advanced, still in the primary stage, and is plagued by some major problems such as lower selling prices of fresh products and easy to decay. The development of Chinese Chestnut processing industry may contribute to the prosperity of products market and the upgrading of industry, which possesses a great market potential, and leads to better social and economic benefits.Nowadays, microwave technology, as a kind of high and new technology, has been rapidly developed in food engineering research and application, and continues to be found a wider utilization. For the moment, the application of microwave technology has been industrialized in such food engineerings as drying, sterilizing and unfreezing, etc. However, there is no report yet about its application in Chinese Chestnut processing both at home and abroad.In this study, microwave technology was introduced into the shelling of Chinese chestnut, and the mechanism of microwave cracking and its technological feasibility were researched with intent to find an efficient way to crack the shell and remove the hull. The results showed that the shelling and hull removing of Chinese chestnut could be achieved by one microwave processing. The processing methods were composed of the treatment of cut chestnut and that of uncut one. The better microwave shelling method for the cut chestnut was showed as follows: choosing → weighing and classifying → dipping in 2% NaCl solution for 7 hours →cutting → continually processing by microwave (full power 750 W) → separating kernel from shell and hull→ chestnut kernel. This method has a strong applicability, and can be utilized in microwave shelling of chestnuts of different weights. While the better microwave cracking method for uncut chestnut was as follows: choosing →weighing and classifying→ preheating and drying(90C, 15min)→ pulsing treatment by microwave(average power 495W) → cracking → separating kernel from shell and hull → chestnut kernel. It should be noticed that different effets of microwave shelling were evidently observed according to various weights of chestnuts. Microwave could impose some effects on the traits of chestnut kernel, such as protecting the vitamin C in it, and obviously inactivate POD enzyme. But the marked destruction of structure of starch crystal was hardly found.