GB/T 15674-2009Determination of crude fat in edible mushroom (English PDF)

Foreword

This standard replaces GB/T 15674-1995 "Edible fat content determination." this standard and GB/T 15674-1995 compared to the main changes are as follows.

--- According to GB/T 20001.4-2001 "Rules for drafting standards - Part 4. Chemical analysis methods," the structure of the original standard the modification;

--- Modify the standard English name;

--- Chapter 2 of the original standard "reference standard" to "normative references", remove the original standard "GB 12530 Edible Sampling methods, "adds GB/T 6682 and GB/T 5009.3 standard two;

--- Modify the "principle";

--- Reagent to remove ether, to petroleum ether, and added celite and hydrochloric acid;

--- Instrument commonly used laboratory equipment to remove the appliance, increased fat analyzer;

--- Sample preparation added to the dry kind of sample size, and the number of clear fresh sample sampling;

--- Increasing the hydrolysis step;

--- Modify the formula "calculation result" in;

--- Original standard "allows poor" to "precision", and another from a chapter, modify the error representation.

This standard is proposed and managed by the People's Republic of China Ministry of Agriculture.

This standard was drafted. the Ministry of Agriculture edible fungus Quality Supervision and Testing Center (Shanghai), Shanghai Academy of Agricultural Sciences of the edible fungi, Agricultural product quality Standards and Testing Technology Research Institute, Shanghai Academy of Agricultural Sciences, Kunming Institute of edible fungi, Tianjin University.

1 Scope

This standard specifies the method for the determination of the fat content of edible fungi.

This standard applies to the determination of the fat content of edible fungi.

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.

Determination of GB/T 5009.3 moisture in foods Laboratory use specifications and test methods GB/T 6682 Analysis Principle 3 Hydrolysis of the sample after boiling hydrochloric acid, cooled, filtered, and the residue is washed until neutral and dried extracted with petroleum ether, the extract dried to constant weight After weighing, the fat content of the sample is calculated.

4 Reagents

Unless otherwise stated, use only in the analysis confirmed analytically pure reagents and third grade water GB/T 6682 regulations.

4.1 hydrochloric acid solution [Ba (HCl) = 3mol/L]. lessons 25mL of hydrochloric acid (rho = 1.18g/mL) in 75mL of distilled water.

4.2 petroleum ether. boiling point in the range of 30 °C ~ 60 °C.

Diatomite 4.3. boiled in hydrochloric acid solution 6mol L/in 30min, washed with water until neutral, dried at 130 °C in.

5 Equipment

5.1 Drying oven, the temperature accuracy of ± 2 °C.

5.2 Analytical balance, sense of volume 0.001g, 0.0001g.

5.3 electric water bath.

5.4 Soxhlet extractor.

5.5 Extraction sleeve.

5.6 fat analyzer to Soxhlet extraction principle manufacture of various types of fat fat analyzer.

5.7 filter paper, medium speed.

5.8 cotton.

5.9 glass beads.

5.10 commonly used laboratory equipment.

6 Sample preparation