GB/T 14613-2008Method for chemical analysis of metallurgy product -- General rules and regulations (English PDF)

Foreword

This revised standard adopts AACC56-50 (1999) "whole wheat flour fermentation time trial." this standard AACC56-50 (1999) The main technical differences are as follows.

--- Dry yeast is used in the test instead of fresh yeast;

--- Increase the quality requirements of dry yeast.

This standard is GB/T 14613-1993 "whole wheat flour fermentation time trial" amendment.

This standard and GB/T 14613-1993 main differences are as follows.

--- The standard name be changed to "Inspection of grain and whole wheat flour fermentation time test (Pelshenke test)";

--- Increasing the normative references;

--- Will use the balance of the "sense of the amount of 0.1g" be replaced by "a sense of the amount of 0.01g".

Since the implementation of this standard, instead of GB /14613-1993 "whole wheat flour fermentation time trial" T.

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. State Administration of Grain Science Institute.

1 Scope

This standard specifies the fermentation time trial (Pelshenke test) the principle of whole wheat flour, instruments and equipment, reagents, sample preparation, determination of step Step and results are shown.

This standard applies to all kinds of whole wheat flour fermentation time test (Pelshenke test).

2 Normative references

Following standard terms of this standard reference and become the standard terms. Any reference to the standard date, 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 references, the latest version applies to this standard.

GB/T 20886-2007 food processing yeast Principle 3 A certain amount of whole wheat flour and knead yeast was mixed into the dough ball into the water 30 °C, because the fermentation of yeast, spherical surface Delegation of carbon dioxide gas content increased, the volume also increased, reduced the proportion, floating to the surface, continue to ferment the dough ball to break disintegration crack. Disintegration began to ferment to the elapsed time is the time value from the fermentation of whole wheat flour dough. Whole wheat flour fermentation time value larger surface wheat Bars the better the quality. Wheat gluten strength classification in Appendix A.

4 Reagents

4.1 dry yeast. Fermentation force should be consistent with GB/T 20886-2007 in 5.2.1 type of high activity dry yeast (sugar type) requirements.

4.2 yeast suspension. 2g of dry yeast (4.1) was dissolved in 100mL of distilled water 30 °C ± 1 °C, placed in 30 °C ± 1 °C thermostatic water Bath (5.1), the preparation day of use.

5 Apparatus

5.1 temperature water bath. Insulation 30 °C ± 1 °C.

5.2 thermostat. Insulation 30 °C ± 1 °C, with a transparent glass door.

5.3 Hammer cyclone mill. built-in aperture 1mm sieve.

5.4 Balance. a sense of the amount of 0.01g.

5.5 Beaker. 150mL, 50mL.

5.6 Pipette. 5mL.

5.7 cylinder. 100mL.

6 Sample Preparation

Take 50g wheat samples, remove impurities, a hammer mill cyclone (5.3) crushing, grinding bore sample cleanup and mesh, and pulverized sample together with and evenly mixed in sealed vial was measured after standing overnight.

7 Measuring step

Weigh 4.0g (accurate to 0.01g) sample (Chapter 6) was poured into 50mL beaker, 2.25mL yeast suspension (4.2), with