In industrial gardens, harvesting takes place according to strict rules. This is due to large financial and time investments in the cultivation and care of walnut trees. Neglect of generally accepted recommendations and rules increases the risk of crop loss, deterioration of its quality and reduced profits.
Immediately after harvesting, the walnut is cleaned of the green pericarp and its residues, and dust and dyes - iodine, juglone and tannins are also washed off.
Despite the fact that the walnut is capable of self-cleaning from the green pericarp, gardeners and agronomists of walnut plantations do not count on it.
Firstly, in large orchards, walnuts are harvested at one time, and nuts, both without a green peel, and completely covered with pericarp, fall into the total mass.
Secondly, more than one week passes from the moment of ripening to the complete cleansing of the nut from the pericarp. It's time that costs money. At the same time, there is a percentage of a walnut that remains in a darkened and dried peel. The number of such walnuts depends on the variety, weather conditions or tree diseases.
Thirdly, the longer the nut is in the pericarp after ripening, the higher the risk of getting a nut with a dark shell, spots on it and a darkened kernel. After the green pericarp ripens and cracks, oxidative processes begin to occur in it, the nut gradually darkens and shrinks. In the process of oxidation, iodine, yulgon and tannins, which are rich in the pericarp, stain the kernel in a dark color.
You can peel a walnut manually with a knife and containers of water. In this case, it is important to consider that everything that the pericarp comes into contact with will darken over time. Therefore, you need to use gloves, work clothes and a specially designated place.
To simplify the procedure for cleaning a walnut from a green pericarp, walnut peeling machines are used. They are household (100 kg/h) and industrial (300 and 700 kg/h, depending on the size of the garden and crop volume).