1.At present, there are not many studies on pecan shell breaking devices in China. The mechanical equipment with high versatility, high shell breaking rate and low kernel breaking rate is almost blank. The main research objects in shell breaking are: walnut, ginkgo, pine seeds, etc. The shell breaking methods of these nuts mainly include: centrifugal collision shell breaking, fixed gap squeeze shell breaking, vacuum shell breaking, ultrasonic shell breaking, and chemical corrosion method. The above methods have some disadvantages: there are many broken kernels, it is not easy to control, the equipment is expensive, the shell is broken, the cost is high, and the kernel is susceptible to corrosion and pollution. The general processing method of peeling pecans by hand is as follows: Put pecans in a special mold and knock them out by hand with a special hammer. After entering the well-off level, people not only demand food safety, nutrition, convenience, health care, but also good taste, which poses a challenge to traditional pecan processing machinery and processing technology. In order to improve product utilization and reduce labor costs, efficient shell breaking equipment is required to shell the pecans. The development and research of automatic peeling pecan processing equipment is one of the technical problems that need to be solved urgently.
2.The processing technology of hand-peeled pecan is briefly introduced as follows: after cooking and astringent, the pecan is sorted and classified, and finally the shell cracking process is performed. That is, pecans of different sizes and sizes are respectively put into different models of indented special molds similar to the shape of a half pecan, and they are beaten with a special hammer with an indentation until the shell cracks, and about 1/5 of the shell is broken. After the cracked shell, sieve to remove the broken shell, dip it into the seasoning solution in the pot, boil for about an hour and drain the water, and then bake the pecan for about an hour at 100 ～ 150 ℃. Broken part of the shell, sieve the shell after the oven, and package the finished product. Because the untreated pecan nuts have a certain astringency, it must be deastringent to make the pecans taste light and crisp. Ordinary farmers and small workshops in the western mountainous areas of our province adopt the family deastringency method: pecan nuts that have been dried by water are placed in special wooden barrels (commonly known as "mountain steaming") and filled with water. Water is generally cooked for 5 to 7 hours. After being taken out, it is dried for 3 to 4 days or dried, which is to completely remove astringency. At this time, pecans can be eaten directly or used as processing raw materials. Larger processing plants generally use high pressure to remove astringency. Put the peeled pecans into a steam bucket and steam it for 1 to 1.5 hours under a hot air pressure of 0.1 MPa. When the flesh of the steamed nuts is light red, the cut surface of the meat is white, and there is no astringency, That's it. In addition, in some deep processing cases, pecan kernels need to be astringent. First, the shell and kernel are separated by hand, and the separated tide kernels are placed in a large container of an appropriate amount of astringent, and soaked in boiling water for about a quarter of an hour. Take it out and rinse it with water, then put it in a stainless steel steamer and steam for another quarter of an hour to completely remove the astringency. The hot steam pressure in the imagination is controlled to within 0.05 MPa. After the pecans are deastringent, they can be further processed. Although the process of hand-peeling pecans is not complicated, it requires high temperature for cooking and frying. Excessive temperature will make the nuts 4 and fatty acids (linoleic acid and linolenic acid) corrupt and deteriorate. Decrease the health function of pecan. Deterioration of the nuts caused by overheating does not appear immediately, but it can take weeks or months to appear. At the same time, temperature is also important for the astringency of pecan nuts. Therefore, temperature control during pecan processing is the key factor to ensure the quality and taste of nuts. At present, in smaller companies and family workshops, the temperature control in the process of hand-peeled pecans basically depends on the experience of the operators. This operation mode has great subjectivity and inaccuracy, and there is uneven drying and drying. The speed is relatively slow, the labor intensity is large, and the energy loss is large. It is difficult to guarantee the baking quality.