Datetime: 2023-02-06 11:55:57 Visit: 0
The character of walnut and its present situation in China
Walnut is also known as walnut, qiang fruit, pecan family walnut genus; together with almond, cashew nut and hazelnut, it is listed as one of the four major dried fruits in the world and has high edible value.
The phospholipid in walnut meat has a good health care effect on the brain nerve; The extracted walnut oil contains a lot of unsaturated fatty acids, which has the effect of preventing arteriosclerosis. Walnut meat contains zinc, manganese, chromium and other indispensable trace elements of the human body, which can supplement the zinc and manganese elements that are decreasing in the aging process of the human body. In foreign countries, walnut is known as "brain fruit", "longevity fruit", "beauty fruit", traditional Chinese medicine that walnut warm, sweet taste, non-toxic, have stomach, blood, lung, spirit and other effects, walnut has a wealth of edible and medicinal value.
Nutritional value and prospect of walnut oil
The oil content of walnut meat is 60% to 70%, which is higher than the oil content of soybeans, rapeseed, peanuts and sesame, known as the "king of woody oil", and the unsaturated fatty acid content is more than 90%. Walnut oil contains linoleic acid and linolenic acid, oleic acid and other components that the human body can not be synthesized, but also contains a variety of vitamins and mineral elements that are beneficial to the human body, such as flavonoids, vitamin E and iron, walnut oil has a beautiful fragrance, rich nutrition, and maintains the nutritional health and pharmacological effects of walnut kernel, so walnut oil is a precious nutritional oil.
In Japan, walnut oil has already become a kind of high-grade health oil, and France also uses it as a high-grade condiment.
Method for pressing walnut oil
The main methods for preparing walnut oil are: supercritical CO2 extraction; Solvent extraction of oil; Water substitution; Aqueous enzyme method; The pressing method.
The above methods have advantages and disadvantages. The process of pressing oil is the process of extruding the oil from the rolling material with the help of mechanical external force. The oil yield of this method is only 50%~60%, and there are some shortcomings such as high residual oil rate, high labor intensity, high cost, large protein denaturation and poor quality in the cake. But this method is simple in equipment and convenient in operation.
At present, the mainstream processing method of walnut oil in China is cold-pressed walnut oil processing technology.
walnut raw materials--shucking--peeling--crushing--hot press--virgin walnut oil--walnut cake--refining--canned refined walnut oil
