CN109663625B

CN109663625B - Method for preparing long-grain rice through secondary processing

Info

Publication number: CN109663625B
Application number: CN201910156338.9A
Authority: CN
Inventors: 沈汪洋; 李春雷
Original assignee: Wuhan Polytechnic University
Current assignee: Wuhan Polytechnic University
Priority date: 2019-03-01
Filing date: 2019-03-01
Publication date: 2021-09-21
Anticipated expiration: 2039-03-01
Also published as: CN109663625A

Abstract

The invention belongs to the field of rice processing, and particularly relates to a method for preparing long-grain rice through secondary processing. The method comprises the following steps: peeling and whitening the long-grain brown rice, removing bran powder, screening and color selecting to obtain a first part of broken rice and whole rice which meet the target processing precision, and a first part of broken rice and whole rice which do not meet the target processing precision and a second part of broken rice and whole rice which are different in color; grinding the broken rice and the whole rice which do not accord with the target processing precision and the broken rice and the whole rice with different colors, removing bran powder, screening and color selecting to obtain the second part of broken rice and whole rice which accord with the target processing precision; mixing the two parts of broken rice and whole rice which meet the target processing precision, and obtaining the long-grain rice without the abnormal color grains after metering, rice bin group cooling, rice blending, polishing and color sorting. The invention can improve the rice yield, reduce the generation of broken rice, is also helpful for reducing the remained skin and remained germ rice in the carrying-out ratio of the color selector, and improves the economic benefit.

Description

Method for preparing long-grain rice through secondary processing

Technical Field

The invention belongs to the field of rice processing, and particularly relates to a method for preparing long-grain rice through secondary processing.

Background

The long-grain rice is easy to increase the broken rice rate in the rice milling process due to long grain shape, and the conventional rice milling process only adopts a sand roller to mill rice, so that the increase of broken rice can be reduced. According to the requirements of the current national standard (rice GB/T1354-. The machining precision indexes mainly include: the degree of residual rice germ and residual skin on the surface and back ditch of rice grains after processing, namely the degree of germ retention and skin retention in the industry. The first-level requirement of the processing precision in the national standard is as follows: the back ditch has no skin or no skin forming, and the rice embryo and grain surface skin layer are removed to be more than 90%; the requirements of the second level are: the back ditch has skin, and the removed rice embryo and grain surface skin accounts for more than 85 percent.

For the current rice processing technology, the aim of peeling and degerming is achieved only by a sand roller rice mill. However, for such a process, the machining precision and the broken rice are two contradictory indexes: in order to achieve the required precision, the pressure or the milling number of the rice mill must be increased, so that a certain broken rice content is increased, and the increase of broken rice directly reduces the economic benefit and increases the cost. If the broken rice is reduced, a part of the skin layer and the rice embryo are reserved, and the rice with the skin and the embryo left in the subsequent process (such as a color sorting process) can be removed as abnormal color and scab grains, so that the carrying-out ratio is increased, the load of equipment is increased, the yield of finished rice is reduced, and the economic benefit is reduced.

Disclosure of Invention

The invention aims to solve the problem that broken rice is increased when processing precision is improved, and combines production practice to change the condition that the processing precision of rice is only controlled by a rice mill. Thereby reducing the phenomenon that the rice which reaches the processing precision is excessively ground to increase the content of broken rice, reducing the carrying-out ratio of the rice which reaches the processing precision after color selection, and improving the yield.

In order to achieve the above object, the present invention provides a method for preparing long-grain rice through secondary processing, the method comprising:

1) peeling and whitening the long-grain brown rice by a first sand roller rice mill in sequence, removing bran powder by a first rice brushing machine, screening by a first white rice grading sieve and carrying out first color selection to obtain a first part of broken rice and whole rice which accord with the target processing precision and a first part of broken rice and whole rice which do not accord with the target processing precision;

2) grinding the broken rice and the whole rice which do not accord with the target processing precision by a second sand roller rice mill in sequence, removing bran powder by a second rice brushing machine, screening by a second white rice grading sieve and performing second color separation to obtain a second part of broken rice and whole rice which accord with the target processing precision;

3) mixing the first part of broken rice and the whole rice which meet the target processing precision and the second part of broken rice and the whole rice which meet the target processing precision, and obtaining the long-grain rice without the abnormal color grains after metering, removing bran powder and excessive water by a rice cooling bin group, blending the rice, polishing and selecting the third color.

According to the invention, the processing precision meeting the target can be the processing precision meeting the national standard or the processing precision set by a person skilled in the art, and the working state of the sand roller rice mill can be adjusted according to the requirement of the target processing precision.

According to a preferred embodiment of the present invention, when preparing long grain rice, a person skilled in the art uses a first abrasive grain mill which is usually a large abrasive grain mill, and a second abrasive grain mill which is usually a small abrasive grain mill, so that the yield of the first abrasive grain mill is higher than that of the second abrasive grain mill.

According to a preferred embodiment of the invention, the first color selection and the second color selection remove the lesion rice and the remained skin rice.

According to a preferred embodiment of the present invention, the third chromatography removes yellow-grained rice and malignant speckles.

According to the invention, the length-width ratio of the long grains is > 3.

The invention has the advantages and positive effects that:

in the invention, the requirement of processing precision can be properly relaxed when the rice mill works, only the whiteness is required to be ensured, and the skin-remaining rice and the germ-remaining rice are selected by the color selector and then are separately processed. The method can improve the rice yield, reduce the generation of broken rice, and is also helpful for reducing the remained skin and remained germ rice in the carrying-out ratio of the color selector. Many small scabs are milled again by the rice mill, and then the parts with the scabs are removed, so that the rice is converted into good rice, and the economic benefit is improved.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Detailed Description

Preferred embodiments of the present invention will be described in more detail below. While the following describes preferred embodiments of the present invention, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Example 1:

this example prepared fine rice grain according to the following process.

Specifically, the method comprises the following steps:

1) the method comprises the following steps of peeling and whitening brown rice by a first sand roller rice mill in sequence, removing bran powder by a first rice brushing machine, removing diseased rice and remained rice by a first white rice classifying screen and a first color selection to obtain a first part of broken rice and whole rice which accord with target processing precision, and broken rice and whole rice which do not accord with the target processing precision and different colors;

2) grinding the broken rice, the whole rice and the different-color broken rice and whole rice which do not accord with the target processing precision by a second sand roller rice mill in sequence, removing bran powder by a second rice brushing machine, removing scab rice and remaining rice by second white rice grading sieve screening and second color separation to obtain a second part of broken rice and whole rice which accord with the target processing precision;

3) and (3) metering the first part of broken rice and whole rice which meet the target processing precision, and the second part of broken rice and whole rice which meet the target processing precision, removing bran powder and excessive water from a rice cooling bin group, mixing rice, polishing, and removing yellow rice and spot grains in a third color selection mode to obtain long rice with the abnormal grains removed.

Wherein the output of the first abrasive roller rice mill is higher than the output of the second abrasive roller rice mill.

Comparative example 1:

the difference from the embodiment 1 is that the process flow is as follows:

the method comprises the following processes of grinding roller rice machine (3 sand), white rice grading sieve, metering, rice cooling bin group, rice blending, polishing, color sorting and the like.

In a large rice processing factory, the process of the example 1 and the process of the comparative example 1 are adopted to sample and calculate the yield in field, compared with the comparative example 1, the yield of the whole rice is increased by 0.6 percent after the process of the example 1 is adopted, and the ratio of the output of a color selector is reduced to 7 percent from 20 percent (the output comprises the skin, the germ, the scab and the good rice).

The factory can process 12 ten thousand tons of rice per year, so that 240 thousand of increment can be generated, and the effect is obvious.

Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for preparing long-grain rice by secondary processing is characterized by comprising the following steps:

3) mixing the first part of broken rice and the whole rice which meet the target processing precision and the second part of broken rice and the whole rice which meet the target processing precision, and obtaining long-grain rice without the abnormal color grains after metering, removing bran powder and excessive water by a rice cooling bin group, blending the rice, polishing and selecting the third color;

wherein, the first color selection and the second color selection remove the diseased spot rice and the remained skin rice;

wherein, the third color selection removes yellow rice and malignant speckles.

2. The method of claim 1 wherein the output of the first abrasive roller rice mill is greater than the output of the second abrasive roller rice mill.

3. The method of claim 1, wherein the long grain meters have an aspect ratio > 3.