Method for drying corn alcohol lees and extracting soluble polysaccharide

Abstract

The invention provides a method for drying corn distillers' grains and extracting soluble polysaccharide. The method comprises the following steps: performing membrane filtration on distillers' grain filtrate to obtain clear liquid and membrane concentrate; performing membrane separation on the clear liquid to obtain a macromolecular polysaccharide component and a small molecule mixture; treating the macromolecular polysaccharide component to obtain a soluble polysaccharide product; concentrating the small molecule mixture to obtain a high-concentration mixture; and mixing the membrane concentrate, the high-concentration mixture and vinasse, and drying to obtain the protein feed. According to the method, the soluble saccharides in the distillers' grains filtrate are extracted, so that the Maillard reaction of the saccharides and amino acids is avoided or reduced, the loss of the amino acids is reduced, the problem that the color of the DDGS feed is darkened when the DDGS feed is dried is solved, and the quality of the DDGS feed is greatly improved. According to the method disclosed by the invention, after soluble polysaccharide in the DDGS feed is extracted, anti-nutritional factors of the feed are reduced, and the situation that the absorption capacity of animals on nutritional ingredients is reduced after the animals intake indigestible polysaccharide is avoided.

Description

technical field [0001] The invention relates to the technical field of DDGS feed production, in particular to a method for drying corn distiller's grains and extracting soluble polysaccharides. Background technique [0002] Currently, alcohol (ethanol) is a very important basic raw material widely used in food, medicine, fuel and so on. The production of alcohol mainly uses starch as raw material. The production process includes raw material cooking, saccharification agent preparation, saccharification, distiller's preparation, fermentation and distillation. DDGS (Distillers Dried Grains with Solubles) feed is the trade name of protein feed in distillers grains, that is, dried distillers grains containing soluble solids. In the process of producing ethanol by fermentation with corn as raw material, the starch in it is converted into ethanol and carbon dioxide, and other nutrients such as protein, fat, fiber, etc. are left in the distiller's grains. [0003] The filtrate ob...

AI Technical Summary

Problems solved by technology

[0006] 1. Evaporation costs are high. Distiller’s lees filtrate is concentrated from 1-5% to 30-50%. It needs to evaporate about 10 tons of water, consume 2-3 tons of steam, and consume a lot of electricity. , higher energy consumption;

[0007] 2. The temperature during evaporation is high, and the evaporation is in a vacuum state, a large amount of organic matter will volatilize, and the evaporated water will take away a lot of organic matter, and the COD of the generated sewage is about 3000 or more, which increases the difficulty of sewage treatment;

[0008] 3. The color of DDGS is a very important quality indicator. Due to the presence of soluble sugars and amino acids in the filtrate, when the filtrate is concentrated, a large amount of amino acids will be consumed due to the Maillard reaction due to high temperature. After the clear liquid is concentrated, when it is mixed with distiller's grains and dried, a large amount of protein contained in distiller's grains will also undergo Maillard reaction with soluble sugars, consume protein, greatly reduce the nutritional value of the feed, and cause the color of DDGS protein feed to turn black, seriously affecting food attractant properties of the product;

[0009] 4. The soluble sugars in the filtrate are polysaccharides. These sugars cannot be used by animals, and will wrap and carry other nutrients, affecting the absorption of nutrients by animals.

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