Preparation method of rice products with low content of heavy metal

Abstract

The invention discloses a preparation method of rice products with a low content of heavy metal. The method comprises the following steps of performing pulp mixing, performing enzymolysis, performing complexing, performing washing separation and performing drying treatment on rice flour or rice protein flour, so that the rice flour or the rice protein flour with a low content of metal is finally prepared. According to the method disclosed by the invention, an enzyme method and a chemical method are used, so that the heavy metal in the rice flour or the rice protein flour is dissociated out in a complexing manner; then solid-liquid separation is performed by a physical method of the stepwise gradient separation of rotational flow, so that the purpose of reducing the content of the heavy metal in the rice flour or the rice protein flour is realized, and a deeply processed product, namely the rice flour or the rice protein flour, with high quality and high added value is prepared. The method is simple to operate and low in cost.

Description

technical field [0001] The invention belongs to the technical field of grain deep processing, and in particular relates to a treatment method for reducing heavy metal content in rice flour and rice protein powder. Background technique [0002] China is the world's largest rice producer. In 2008, the rice output was 189 million tons. Rice is my country's largest food crop. However, the quality of the soil in various places is directly related to the quality of edible rice. However, the adsorption of heavy metal pollution by rice It is obviously stronger than other crop varieties such as corn and soybean. Therefore, the rice is processed through deep processing to obtain high-quality products while removing heavy metals, which also increases the added value of rice utilization. [0003] Heavy metals in rice are mainly combined with amino acids in a chelated state. It is reported that heavy metals in plants are mainly combined with ligands formed by metallothionein, and some of...

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Problems solved by technology

[0004] The invention patent of CN201310140019.1 discloses a decadmium-depleted rice protein and its preparation method and application. The main steps are to use rice as raw material, remove starch with high-temperature amylase to obtain rice dregs, and then use acid solution for decadmium treatment , the acid used is one of food-grade acetic acid, citric acid, malic acid, lactic acid, tartaric acid, oxalic acid, and phosphoric acid. It only plays the role of adjusting the pH value; the acid solution with a large amount of acid and pH<4 has a negative effect on the quality of the protein; the rice protein obtained by centrifugation is directly washed with water, due to the increase of the pH value, the dissolved in the solution Cadmium ions are recombined with rice protein, reducing the efficiency of cadmium removal in the final product; and the supernatant and washing liquid also contain more acid solution, which is not considered in the invention patent that its discharge will pollute the environment a little

[0005] The invention patent of CN103340414A discloses a method for removing cadmium from rice protein. The invention includes the following steps: slurry mixing, acid hydrolysis reaction, impurity removal, sterilization, dehydration, and drying to obtain rice protein powder. The acid hydrolysis reaction of the invention uses Citric acid adjusts the pH value to 3.8-4.2, and then adjusts the pH value back to 5.8-6.2 with alkaline solution. The cadmium ions dissolved under acidic conditions recombine with rice protein as the pH value increases, which reduces the cadmium removal. efficiency; although the invention uses a cyclone scrubber, its main purpose is to separate and remove impurities, and to separate the supernatant from the solid phase after alkali adjustment

[0006] The invention patent of CN104000085A discloses a preparation method of decadmium-removed rice starch and decadmium-removed rice protein powder. In the step of cadmium in rice protein, at least one of acetic acid, lactic acid, oxalic acid, citric acid, tartaric acid, and citric acid with pH<4.2 is mainly used to react according to the volume ratio of rice raw material to acid of 1:3-5. In the invention, the acid is mainly used to adjust the pH value, and this addition has a negative impact on the quality of rice protein and rice sta

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