GB 5009.2-2024 National food safety standard - Determination of relative density of food
1 Scope
This standard specifies the method for determining the relative density of liquid foods.
This standard is applicable to the determination of the relative density of liquid foods.
Method I Density bottle method
2 Principle
Weigh the mass of water and the specimen filled in the same density bottle at 20°C respectively. The volume of the density bottle, which is the volume of the specimen, may be determined by the mass of water. The density of the specimen may be calculated based on the mass and volume of the specimen. The ratio of the specimen density to the water density is the relative density of the specimen.
3 Instruments and apparatus
3.1 Density bottle: Precise density bottle, see Figure A.1 of Annex A.
3.2 Thermostatic water bath: with precision of ±1°C.
3.3 Analytical balance: with the sensitivity of 0.1 mg.
4 Analysis procedures
Take a clean, dry, constant-weight and accurately weighed density bottle, fill it with specimens, soak it in a water bath for 0.5h to make the temperature of the specimen reach (20±1)°C, cover the bottle cap, suck the specimen on the branch pipe marking with a thin filter paper strip. After covering the small cap, take it out and dry the outer wall of the density bottle with filter paper. Place it in a balance room for 0.5h for accurate weighing. Pour out the specimen again, wash the density bottle, fill it with water, and immerse it in a water bath for 0.5h until the temperature of the contents reaches (20±1)°C. Cover the bottle cap and use a fine filter strip to suck off the water on the branch pipe marking. After covering the small cap, take it out and dry the outer wall of the density bottle with filter paper. Place it in a balance room for 0.5h for accurate weighing. Caution: There shall be no bubbles inside the density bottle, and the temperature inside the balance room shall be kept at (20±1)°C.
Contents
Foreword i
1 Scope
2 Principle
3 Instruments and apparatus
4 Analysis procedures
5 Expression of analysis results
6 Precision
7 Principle
8 Instruments and apparatus
9 Analytical procedures
10 Expression of analysis results
11 Precision
12 Principle
13 Instruments and apparatus
14 Analytical procedures
15 Expression of analysis results
16 Precision
17 Principle
18 Instruments and apparatus
19 Analytical procedures
20 Expression of analysis results
21 Precision
Annex A Schematic diagram of density bottle
Annex B Schematic diagram of Wechsler relative density balance
