How to peel walnuts quickly?

Different peeling processes of 1 walnut kernel

1. 1 pure manual peeling method

The pure manual peeling method is to peel off the inner seed coat by hand without any assistance. This method has the advantages of clean peeling, low loss rate and good nutrition maintenance. However, because the inner seed coat tightly wraps the whole walnut kernel, and the walnut kernel is wrinkled and the ditch is full of cloth, manual peeling is difficult, time-consuming and inefficient. It is feasible for fresh walnut kernels, and is generally used in the case of small production scale or poor mechanical equipment.

1.2 boiling water peeling method

Boiling water peeling method is to put walnut kernels directly into water and heat them to boiling, then stop heating, stew for a certain period of time and take them out, and peel them manually or with a high-pressure water gun. The principle is that nucleolus expands when heated and contracts when cooled, so that nucleolus is separated from endosperm. The longer the stew, the better the peeling effect will be. However, with the extension of stewing time, the walnut kernel will be fluffy, the texture will become worse, and some nutrients will be dissolved in water, resulting in the loss of nutrients. The peeling effect of single boiling water peeling method is poor, and it is generally suitable for small batch production or combined with other peeling methods.

1.3 baking peeling method

Baking method is to put the walnut kernel in the oven, bake it for a certain period of time, take it out and cool it, and rub it by hand based on the principle of thermal expansion and cold contraction. It is important to master the temperature and time of baking. If the baking is not sufficient, the peeling effect will not be achieved and the rich fragrance will not be produced. If it is baked too much, it will lead to degeneration, yellowing and even coking of protein, resulting in burnt taste. The single baking and peeling method has poor effect, is easy to burn, consumes a lot of nutrients in walnut kernel, is difficult to control, and is not suitable for mass production. However, baking peeling method can be combined with other methods, such as appropriate boiling water peeling method and baking, which can achieve better peeling effect and effectively maintain the texture, color and fragrance of walnut kernel. Kang Weili and others used hot air baking-microwave peeling technology to remove the endocarp of walnut. The optimum technological conditions are: microwave power 769 W, microwave time 565438 0 s, baking temperature 65438 030℃ and baking time 65438±06min. The peeling rate of walnut kernel can reach 98. 05438+0%. Liu Huiping baked the walnut kernel, cooled it quickly, peeled it with pulsating air, and manually selected it to get the walnut kernel with the inner seed coat removed. The walnut kernel product without inner seed coat obtained by baking is crisp and rich in flavor, which shortens the production cycle. If it is combined with high-tech such as pulsating gas peeling, it is especially suitable for the processing and production of high-grade walnut products.

1.4 alkaline solution immersion peeling method

The endocarp and kernel of walnut are firmly combined together because of pectin. The walnut kernel is soaked in dilute alkali solution at a certain temperature, so that the pectin layer between the inner seed coat and the kernel is dissolved, the whole skin of the inner seed coat falls off, and the skin block is easy to remove. However, when the alkalinity is too strong, it will not only corrode the seed coat, but also corrode the pulp, resulting in the loss of pulp quality. At the same time, the texture of walnut kernel becomes soft and the color turns white, which affects the taste of the final product and is not conducive to subsequent processing and utilization. If the soaking time is shortened to peeling, the ideal peeling effect will not be achieved because the dilute lye has not had time to wet the nucleolar epidermis.