GB/T 5009.10-2003 Determination of crude fiber in plant foods

This standard specifies the method for determining the crude fiber content in plant foods. This standard is applicable to the determination of crude fiber content in plant foods. GB/T 5009.10-2003 Determination of crude fiber in plant foods GB/T5009.10-2003 Standard download decompression password: www.bzxz.net

ICS67.040
National Standard of the People's Republic of Chinabzxz.net
GB/T5009.10-2003
Replaces GB/T5009.10—1985
Determination of crude fiber in vegetable foods
Determination of crude fiber in vegetable foodsIssued on August 11, 2003
Ministry of Health of the People's Republic of China
Standardization Administration of the People's Republic of China
Implementation on January 1, 2004
GB/T5009.10—2003
This standard replaces GB/T5009.10—1985 "Method for determination of crude fiber in foods". Compared with GB/T5009.10-1985, this standard has been modified as follows: 1. The Chinese name of the standard has been modified, and the Chinese name of the standard has been changed to "Determination of crude fiber in plant foods"; the structure of the original standard has been modified in accordance with GB/T20001.4-2001 "Standard Preparation Rules Part 4: Chemical Analysis Methods".
This standard is proposed and managed by the Ministry of Health of the People's Republic of China. This standard is drafted by the Food Hygiene Supervision and Inspection Institute of the Ministry of Health. This standard was first issued in 1985 and this is the first revision. 68
1 Scope
Determination of crude fiber in plant foods
This standard specifies the method for determining the crude fiber content in plant foods. This standard is applicable to the determination of crude fiber content in plant foods. 2 Principle
GB/T5009.10—2003
Under the action of sulfuric acid, sugar, starch, pectin and hemicellulose in the sample are hydrolyzed and removed, and then treated with alkali to remove protein and fatty acids. The remaining residue is crude fiber. If it contains impurities insoluble in acid and alkali, it can be removed after ash treatment. 3 Reagents
3.11.25% sulfuric acid.
3.21.25% potassium hydroxide solution.
3.3 Asbestos: Soak asbestos in 5% sodium hydroxide solution, reflux on a water bath for more than 8 hours, and then wash it thoroughly with hot water. Then reflux it with 20% hydrochloric acid on a boiling water bath for more than 8 hours, then wash it thoroughly with hot water and dry it. After burning at 600℃~700℃, add water to make a suspension and store it in a glass bottle.
4 Analysis steps
4.1 Weigh 20g~30g of the crushed sample (or 5.0g of dry sample), transfer it to a 500mL conical flask, add 200mL of boiling 1.25% sulfuric acid, heat to a slight boil, keep the volume constant, maintain for 30 minutes, and shake the conical flask once every 5 minutes to fully mix the contents.
4.2 Remove the conical flask, filter it with linen cloth immediately, and wash it with boiling water until the washing liquid is not acidic. 4.3 Use 200mL of boiling 1.25% potassium hydroxide solution to wash the residue on the linen cloth into the original conical flask, heat it to a slight boil for 30 minutes, remove the conical flask, filter it with linen cloth immediately, wash it with boiling water 2 to 3 times, and transfer it to a dry and weighed G2 vertical melting crucible or vertical melting funnel of the same model, filter it by suction, wash it with hot water, and then drain it. Then wash it with ethanol and acetaldehyde in turn. Dry the crucible and its contents in an oven at 105°C and weigh them. Repeat the operation until the weight is constant. If the sample contains a large amount of insoluble impurities, the sample can be transferred to an asbestos crucible, dried and weighed, and then transferred to a 550°C high-temperature furnace for ash treatment. All carbon-containing substances are ashed, placed in a dryer, cooled to room temperature and weighed. The amount lost is the crude fiber amount. 4.4 The result is calculated according to formula (1).
×100%
Where:
X--the crude fiber content in the sample;
G--the mass of the residue (or the mass lost in the high-temperature furnace), in grams (g); the mass of a sample, in grams (g). The calculated result is expressed to one decimal place. 5 Precision
The absolute difference between two independent measurement results obtained under repeatability conditions shall not exceed 10% of the arithmetic mean. (1)
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