Method for extracting sweet potato dietary fibers

Abstract

The invention discloses a method for extracting sweet potato dietary fibers, which belongs to the field of bioengineering and is easy in raw material getting, high in efficiency and environmental-friendly. The method comprises the steps of starch removal, enzymatic hydrolysis, centrifugation and dietary fiber extraction, wherein the insoluble dietary fiber extraction comprises insoluble dietary fiber extraction and soluble dietary fiber extraction; the insoluble dietary fiber extraction comprises the processes of centrifuging the enzymatically hydrolyzed mixed solution to obtain precipitates and supernatant separated from each other, soaking the obtained precipitate with ethanol and then carrying out suction filtration to obtain solids and filtrate, wherein the obtained solids are insoluble dietary fibers; and the soluble dietary fiber extraction comprises the processes of carrying out water bath to evaporate most of the moisture of the obtained supernatant and filtrate, then adding ethanol to carry out digestion so that flocculent precipitates appear in the supernatant and the filtrate, and separating the flocculent precipitates from the supernatant and filtrate, wherein the obtained flocculent precipitates are soluble dietary fibers.

Description

technical field [0001] The invention discloses a method for extracting sweet potato dietary fiber, which belongs to the field of bioengineering. Background technique [0002] Dietary fiber has strong oil-holding, water-swelling, water-holding, solubilizing, binding and exchanging cations, adsorption and chelation of organic compounds, and induction of microorganisms. It can prevent and treat a variety of diseases, known as The "seventh nutrient" after starch, protein, fat, vitamins, minerals and water. [0003] Existing methods for extracting dietary fiber are: remove starch, adjust Ph, enzymolysis, extract dietary fiber, such as Chinese patent 200710038695.2, the preparation method of sweet potato dietary fiber containing sweet potato resistant starch: first cut fresh sweet potato into fine After drying and drying, crush it with a pulverizer, wash away part of the sweet potato starch with water, then add 8 to 15 times the amount of water to the residue, stir to form a slur...

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Problems solved by technology

[0003] Existing methods for extracting dietary fiber are: remove starch, adjust Ph, enzymolysis, extract dietary fiber, such as Chinese patent 200710038695.2, the preparation method of sweet potato dietary fiber containing sweet potato resistant starch: first cut fresh sweet potato into fine After drying and drying, crush it with a pulverizer, wash away part of the sweet potato starch with water, then add 8 to 15 times the amount of water to the residue, stir to form a slurry, heat, gelatinize and cool, add α-amylase hydrolysis, amylase hydrolysis, and dilute hydrochloric acid to adjust its pH value to 4 to 5, then add glucoamylase for hydrolysis, and then wash away the soluble part with water, and finally obtain sweet potato dietary fiber containing sweet potato resistant starch. The method mainly uses α-amylase and glucoamylase. The disadvantages of this method are: 1. A large amount of protein and residual enzymes remain in the sweet potato fiber containing resistant starch, and the purity of the extracted product is low. Therefore, the subsequent application of this product Some side effects may occur due to the presence of active protein; 2. During the washing process, a part of resistant starch is lost, and the extraction efficiency of effective substances is low; 3. The obtained fiber is insoluble, not drinkable, and has a rough taste Difficult to swallow

[0004] Sweet potato contains starch, lipid protein and dietary fiber. Dietary fiber includes soluble dietary fiber and insoluble dietary fiber. Chinese patent 200810234538.3 describes a process for continuously extracting sweet potato starch, sweet potato protein and dietary fiber from sweet potato. After washing the sweet potato Add color protection solution, pulverize, grind, and press to separate sweet potato residue and cell fluid. After combining the cleaning liquid of sweet potato residue and cell fluid, pass through a 200-mesh standard sieve, and the filtrate is centrifuged and dehydrated twice to obtain starch. After the starch milk is degraded by the furnace industry, the starch is degraded, the molecular weight cut-off is 5000-10000, the ultrafiltration is concentrated, and the sweet potato crude protein is obtained. The sweet potato residue is added to the bioreactor, and water is added. Insoluble sweet potato dietary fiber, the disadvantages of this method are: 1. The soluble dietary fiber that is more easily utilized by the human body is not collected; 2. The extracted sweet potato fiber contains more sugar impurities, and the product purity is low; 3. The whole extraction High energy consumption and high cost in the process

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