What is the use of the residue after peanut oil extraction

When it comes to what can be made from peanuts, the first things that come to our mind are snacks and peanut oil. Among various edible oils, peanut oil is a vegetable oil that is liked and accepted by many people. Peanuts are the main raw material for making peanut oil. But everyone also knows that after the peanuts are pressed, there will be a lot of oil residue. So, what is the use of the residue after peanut oil is pressed?

Peanut meal is the product obtained by pressing and refining peanut kernels into oil. Usually, peanut meal is divided into primary meal and secondary meal. But in reality, in addition to peanut meal, there are also peanut cakes and peanut residue. So what are the differences between them? Here is an introduction: the difference between peanut residue, peanut meal and peanut cake: peanut residue refers to the peanut residue left after peanuts are used to extract oil.

There are two types of peanut cakes: one is made from peanut residue after oil is extracted from peanuts, which is then pressed into peanut cakes using a mold; the other is made from fried or roasted peanuts, then added with syrup or malt syrup.

Peanut meal is the peanut residue with broken shells left after the shelled peanuts are directly pressed for oil. Generally, people cannot eat it.

Nutritional characteristics of peanut cake and peanut meal: Peanut cake and peanut meal are processing by-products of peanut kernels after shelling and pressing or de-oiling. The protein content of peanut cake and peanut meal is very high. Generally, the protein content of peanut cake is about 44%, and that of peanut meal is about 48%, which is higher than that of soybean cake and meal. However, the protein quality is poor and the amino acid content is unbalanced. The lysine and methionine contents are low, about 1.35% and 0.40% respectively; the arginine content is particularly high, at 5.2%, the highest among all plant feeds.

The ratio of lysine to arginine is above 100:380. When feeding, it can be combined with protein feed with low arginine content, such as corn, blood meal, etc., to achieve amino acid complementarity and better results. The crude fiber content of peanut cake and meal is not high, averaging 6%. The metabolizable energy value is relatively high, averaging around 11.0 MJ/kg, the highest among cakes and meal types. Peanut cake and meal have good palatability.

Peanut cake and meal contain trypsin inhibitors, which are about 20% of raw soybeans and can be removed by heating during the oil extraction process. Peanut cake and meal are very susceptible to infection by Aspergillus flavus, which produces aflatoxins, with Aflatoxin B being the most toxic. Peanut cake and meal are easily infected by Aspergillus flavus and produce aflatoxin. There are many types of aflatoxins, the most toxic of which is aflatoxin B1. Steaming and dry heat are ineffective in removing aflatoxins, so the aflatoxin content in peanut cake and meal should be strictly tested. Chicks are more sensitive to it. After poisoning, they will show listlessness, drooping wings, feather loss, bloody feces, and unstable gait. In order to avoid the growth of Aspergillus flavus, my country's feed raw materials stipulate that the moisture content of peanut cake should not exceed 12%, and the Aspergillus flavus content should be controlled. According to my country's feed hygiene standards, the content of aflatoxin B in peanut cake is ≤0.05 mg/kg, the content of aflatoxin in broiler and growing chicken feed is ≤0.01 mg/kg, and the content in laying hen feed is ≤0.02 mg/kg. The use of peanut cake and meal in chicken diet is suitable for adult chickens. The dosage in the growing period can reach 6%, and the dosage in laying hens can reach 9%. However, in order to avoid aflatoxin poisoning, it is best not to use them in chicks and broilers in the early stage. The dosage in other stages should be less than 4%. Application of peanut residue: Can peanut residue from oil extraction be used as fertilizer? In fact, peanut residue is what we call oil residue, which can be a good organic fertilizer after processing. Although peanut residue can be a good organic fertilizer after processing, unprocessed peanut residue cannot be used directly as fertilizer. It needs to be fermented before use, because if raw peanut residue is used directly, it may burn the roots.

There are generally two ways to make peanut residue fertilizer, one is water-based fertilizer, and the other is dry-based fertilizer (mixed with soil-based fertilizer).

To make water-fertilizer, use a large-mouthed glass bottle (plastic bottle is also fine), fill it with one-third to one-half of peanut residue, add water to 80-90% of the bottle (don't fill it too full at first, to prevent it from overflowing after fermentation), cover it but do not seal it (to prevent the air pressure from increasing after fermentation, which may cause the bottle to burst or the fertilizer to rush out when it is opened, which is very smelly), preferably outdoors in the sun, stir it from time to time, and leave it for more than two months (in summer) before use. Water can be added as needed. When it is newly put into use, the amount of fermented fertilizer with high fertility should be less (depending on the requirements of the plants). To reduce the smell of fertilizer water, you can add some orange peels.

Dry fermentation: Mix it with soil in a ratio of 1:1 and ferment for more than 6-12 months. You can also add other organic matter, such as orange peel.

The above introduces the differences between peanut cake, peanut meal and peanut residue. I hope the above introduction is helpful to everyone. In addition to the above introduction, we also need to remind everyone that peanut meal can easily be infected with Aspergillus flavus and produce aflatoxin. Therefore, we should take care to prevent aflatoxin infection.