GB/T 21305-2007Cereals and cereal products -- Determination of moisture content -- Routine reference method (English PDF)

Foreword

This standard is equivalent to international standards ISO 712:1998 "cereals and cereal products - Determination of water content in the conventional method" (in English).

Content and structure of this standard and ISO 712:1998 agreement, made the following editorial changes.

--- The "this International Standard" by "this standard";

--- Deleted international standards foreword;

--- "Range" in the "determination of corn moisture implementation of ISO 6540" replaced by "the determination of corn moisture execution GB/T 10362";

--- Is calculated according to GB/T 1.1-2000 requirements plus number.

Appendix A of this standard is an informative annex.

The standard proposed by the National Food Authority.

This standard by the National Standardization Technical Committee OILS.

This standard was drafted. National Food Reserve Wuhan Science Research Institute, Henan feed grain and oil product quality supervision and inspection.

1 Scope

This standard specifies the conventional method for cereals and cereal products Determination of moisture content.

This standard applies to whole grain and pulverized particles measuring the moisture content of the following products. wheat, durum wheat, rice (paddy, brown and white M), barley, millet, rye, oats, triticale, sorghum.

This standard does not apply to maize.

2 Normative references

The following documents contain provisions which, through reference in this standard and become the standard terms. For dated references, subsequent Amendments (not including errata content) or revisions do not apply to this standard, however, encourage the parties to the agreement are based on research Whether the latest versions of these documents. For undated reference documents, the latest versions apply to this standard.

ISO 711 Cereals and cereal products - Determination of moisture content of the Basic Law

3 Terms and Definitions

The following terms and definitions apply to this standard.

Follow the steps specified in this standard dry sample mass of material lost, usually expressed as a mass fraction.

Principle 4

If necessary, pre-treated sample is then pulverized, dried at 130 °C ± 3 °C, the results should be a basic test method (See ISO 711) unanimously.

5 Instruments

Usual laboratory equipment, including in particular the following instruments.

5.1 Analytical balance. accuracy 0.001g.

5.2 pulverizing mill, should meet the following requirements.

a) the material does not absorb water;

b) easy to clean, the smallest possible dead volume;

c) can be quickly and evenly crushed samples, grinding process without significant fever, and little contact with the outside air, and as far as possible;

d) grinding fineness can be adjusted to meet the requirements of 7.1.

5.3 Metal dish. corrosion (if corrosion, you can use a glass dish) under test conditions, with considerable supporting tight lid. Its surface area enables test Like spread of not more than 0.3g/cm2.

5.4 Oven. electric heating mode, the temperature can be controlled at 130 °C ± 3 °C.

Heat oven capacity should meet the initial temperature 131 °C, put the maximum number of samples, it could back up to the starting temperature within 30min.

Recovery oven temperature and ventilation efficiency with a top size of 1mm of durum wheat semolina as a sample was measured when the maximum number of After the sample was placed in an oven at a temperature of 130 °C ± 3 °C dried, the same number of samples was heated 2h, was measured; then reheated GB/T 21305-2007/ISO 712:1998