GB/T 21499-2024Inspection of grain and oils - Determination of the potential milling yield from paddy and from husked rice (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for standardization work Part 1: Structure and drafting rules for standardization documents" Drafting.

This document replaces GB/T 21499-2008 "Determination of potential rice yield of rice, paddy and brown rice" and is consistent with GB/T 21499-2008.

In addition to structural adjustments and editorial changes, the main technical changes are as follows.

--- The sampling method has been changed (see Chapter 6, Chapter 6 of the 2008 edition);

--- Changed the sample preparation method (see Chapter 7, Chapter 7 of the 2008 edition);

--- Changed the adjustment of experimental rice mill (see 8.1.2, 8.1.2 of the 2008 edition);

--- Changed the determination of brown rice rate and added the recommended minimum sample size (see 8.2, 8.2 of the 2008 edition);

--- Changed the result calculation, added the requirement of two parallel tests, and changed the calculation formula (see Chapter 9, Chapter 9 of the 2008 edition). chapter).

This document is equivalent to ISO 6646:2011 "Determination of potential yield of rice, paddy and brown rice". The following minimal editorial changes were made to this document.

--- To coordinate with the existing standards, the name of the document is changed to "Determination Method of Potential Rice Yield of Paddy and Brown Rice for Grain and Oil Inspection";

---Added notes in Chapter 7;

--- Added note in 8.1.2.

1 Scope

This document defines the terms and definitions for the determination of potential rice yield of paddy and brown rice, and describes the principles, instruments and utensils of the determination method, Sample preparation, measurement steps, result calculation, precision and test report.

This document is applicable to the laboratory using rice milling equipment to measure the brown rice rate of paddy or parboiled rice and the whole rice, parboiled rice or brown rice, parboiled brown rice Determination of polished rice rate.

2 Normative references

The contents of the following documents constitute essential clauses of this document through normative references in this document.

For referenced documents without a date, only the version corresponding to that date applies to this document; for referenced documents without a date, the latest version (including all amendments) applies to This document.

ISO 7301 Rice Specification

3 Terms and definitions

For the purpose of this document, the terms and definitions defined in ISO 7301 and the following apply.

4 Principle

The clean rice sample was husked by a rice husker to obtain brown rice, which was weighed. The brown rice was milled with an experimental rice mill to remove a certain amount of cortex and germ, and the weight was measured.

Take the mass of rice and whole polished rice, and calculate the mass fraction of brown rice, rice and whole polished rice in the rice sample.