Investigation of the processing of walnut fruits using low temperatures

Abstract

The most important issue when working with nuts is their processing from the shell and peel. Previously, this process was carried out entirely by hand, but today with a higher demand and developed logistics services, the scale of production of the finished product has increased, which entails an increase in the productivity of lines for the destruction of walnut shells. The purpose of this work is to study the effect of low temperatures on the load exerted on the hazelnut shell during its destruction. The tasks to be solved in this work are the development of an experimental stand that allows you to control all the necessary parameters, the receipt of experimental material, its description with further recommendations when introducing the proposed technology into the industry. The maximum effect on the destruction of the hazelnut shell is achieved by freezing it in nitrogen for 15 minutes, the load being about 208.3 N. This duration is optimal when using liquid nitrogen, because during this period of cryogenic freezing, the limiting deformations of destruction are reduced, the hazelnut shell becomes as fragile as possible and is easily destroyed when the nuts are exposed to shock deformations, and the integrity of the nut kernels is preserved as much as possible. So the load for the destruction of the shell of a hazelnut after treatment with liquid nitrogen is reduced by 39%, compared with untreated, which in production conditions will make significant energy savings for the drive of equipment for the destruction of walnut.