GB/T 5009.117-2003 Analytical methods for hygienic standards of edible soybean meal

This standard specifies the analytical method for the hygienic standard of edible soybean meal. This standard is applicable to the analysis of various hygienic indicators of soybean meal used as raw materials in the food industry after edible soybean oil is extracted from soybeans by solvent. GB/T 5009.117-2003 Analytical method for hygienic standard of edible soybean meal GB/T5009.117-2003 Standard download decompression password: www.bzxz.net

ICS67.040
National Standard of the People's Republic of China
GB/T5009.117--2003
Replaces GB/T14932.2-1994
Method for analysis of hygienic standard ofediblesoybeanmeal
Promulgated 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/T5009.117—2003
This standard replaces GB/T14932.2—-1994 "Method for analysis of hygienic standard of edible soybean meal". This standard has modified the structure of the original standard according to 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. The drafting units of this standard are: Shanghai Food Hygiene Supervision and Inspection Institute, Jilin Province Food Hygiene Supervision and Inspection Institute, Shanghai Nanshi District Health and Epidemic Prevention Station.
The main drafters of this standard are: Shen Wen, Cheng Kaitai, Shen Jingwei, Liu Guixin, Jin Xiuhua. The original standard was first issued in 1994, and this is the first revision. 82
1 Scope
Analysis methods for hygienic standards of edible bean grains
This standard specifies the analysis methods for hygienic standards of edible bean boxes. GB/T5009.117-2003
This standard is applicable to the analysis of various hygienic indicators of soybean dregs used as raw materials for the food industry after edible soybean oil is extracted from soybeans by solvents. 2 Normative referencesWww.bzxZ.net
The clauses in the following documents become the clauses of this standard through reference in this standard. For all referenced documents with dates, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties that reach an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For all referenced documents without dates, the latest versions are applicable to this standard. GB/T5009.3 Determination of moisture in food
GB/T5009.4 Determination of ash in food
GB/T5009.5 Determination of protein in foodGB/T5009.11 Determination of total and inorganic tartar in foodGB/T5009.12 Determination of lead in food
GB/T 5009.37
3 Sensory inspection
Analysis method of edible vegetable oil hygiene standard should be yellow or brownish yellow flakes, with the color and smell of bean sticky, without change, insect marks, debris, oil stains, etc. 4 Physical and chemical examination
The determination of moisture shall be carried out according to the method specified in GB/T5009.3. 4.22
The determination of ash shall be carried out according to the method specified in GB/T5009.4. The determination of crude protein shall be carried out according to the method specified in GB/T5009.5. 4.3
The determination of total urea shall be carried out in accordance with the method specified in GB/T5009.11. The determination of lead shall be carried out in accordance with the method specified in GB/T5009.12. 4.5
5 Enzyme activity
5.1 pH increment method
5.1.1 Principle
Urease in soybean meal can decompose urea to produce ammonia, which increases the pH value in the system. Use a pH meter or acid-base indicator to measure the pH change to determine the urease activity.
5.1.2 Reagents
5.1.2.1 Urea (GB696), analytical grade. 5.1.2.2 0.05mol/L potassium dihydrogen phosphate solution: Weigh 5.0706g potassium dihydrogen phosphate (K, HPO, ·3H, O), dissolve in freshly boiled distilled water, cool and transfer to a 500mL volumetric flask, and dilute to the mark. 5.1.2.3 0.05mol/L potassium dihydrogen phosphate solution: weigh 3.40g potassium dihydrogen phosphate (KH,PO,). Add to freshly boiled steamed stuffing water to dissolve, transfer to a 500mL volumetric flask after cooling, and dilute to the mark. 5.1.2.4 Phosphate buffer (pH7.0): Mix 61.1mL potassium dihydrogen phosphate solution and 38.9mL potassium dihydrogen phosphate solution. This solution can be stored for three months.
GB/T5009.117—2003
5.1.3 Instruments
5.1.3.1 pH meter: The sensitivity should reach 0.02pH unit. It should be equipped with a calomel electrode and a glass electrode for use with it. 5.1.3.2 Constant temperature water bath: The temperature is 30℃±5℃. 5.1.4 Analysis steps
Weigh 10.0g of the sample that has been crushed (about 40 mesh, and heat should be avoided during the crushing process). Place it in a stoppered conical flask, add 100.0mL of water, shake for 30min, filter the sample solution for later use (it is best to measure it on the same day). Pipette 2.0mL of the sample solution and place it in a stoppered colorimetric tube. Add 8mL of pH buffer and 0.2g of urea. Shake well for 1min, place it in a 30℃±5℃ water bath and keep it warm for 30min. At the same time, make a sample solution blank, that is, 2.0mL of sample solution, add 8.0mL of graded buffer. Keep it warm in a water bath at the same time. After the tube contents are cooled, measure the pH value. 5.1.5 Calculation of results
Calculate according to formula (1):
X = pH -pH.
Where:
X-urea alcohol activity index:
pH—pH value of sample solution after decomposition of urea;
pH,m pH value of blank tube of sample solution.
5.2 Simple determination method
5.2.1 The principle is the same as 5.1.1.
5.2.2 Reagents
5.2.2.1 Urea (GB696). Analytical grade.
5.2.2.2 Phenol red indicator: Weigh 0.1g phenol red, add 1.43mL 0.1mol/L sodium hydroxide solution, grind in a mortar to promote dissolution, then transfer to a 250mL volumetric flask, add water to the scale, shake well and set aside. 5.2.3 Analysis steps
Take 0.2g powder sample (avoid heating during crushing), put it in a 25mL colorimetric tube, add 0.02g urea, add 2 drops of phenol red indicator, then add 20mL water, shake well for 15s, record the time when the pink color appears, and judge the urease activity based on the time. The color appearance time should be less than 15min.
Color appearance time
1min~5min
5 min~~15min
At the same time, perform a blank control test.
Urease activity
Sample blank (without urea) and reagent blank (without sample). Only when the above blanks are normal, that is, the phenol red indicator does not change color, the test results are reliable.
6 Solvent residue
6.1 Principle
Same as GB/T5009.37.
6.2 Reagents
Same as GB/T5009.37.
6.3 Instruments
Same as GB/T5009.37.
6.4 Analysis steps
6.4.1 Preparation of standard curve
GB/T5009.117-2003
Take the infusion bottle, inject 0.5μL of No. 6 solvent along the wall with a 1uL microinjector, quickly plug the rubber reverse stopper, seal the aluminum cap, and heat in an oven at 80℃±2℃ for 2h. Take it out and cool to room temperature. Use a 100μL microinjector to inject 20, 40, 60, 80, and 100μL of air into the chromatograph respectively, with the chromatographic peak height as the vertical axis and the corresponding sample solvent content as the horizontal axis to prepare the standard curve. When the standard curve is prepared in full according to this method, the following corresponding relationship is presented (see Table 1): Table 1
Standard headspace air injection volume/μL
Corresponding solvent content in the sample (X)/(mg/kg) 6.4.2 Wherein X is calculated by formula (2):
Wherein:
X—residual solvent in the sample, in mg/kg; V,——amount of No. 6 solvent taken, in microliter (μL); D—relative density of No. 6 solvent, 0.7 mg/μL; V, standard headspace air injection volume, in microliter (μL); V,—sample headspace air injection volume, in microliter (μL); V—volume of infusion bottle, in milliliters (mL); m
sample mass, in grams (g).
6.4.3 Sample determination
Take a 100mL infusion bottle, place two circular filter papers with diameters slightly smaller than the inner diameter of the bottle bottom in the bottle, add 0.5mL of water to the filter papers so that the filter papers stick to the bottom of the bottle, and weigh 2.00g soybean meal, placed on the filter paper in the bottle, immediately plugged with a rubber stopper, sealed with an aluminum cap, and then heated in an oven at 80℃±2℃ for 2h. After the sample bottle is heated and vaporized, it is cooled to room temperature, and 100μL of headspace gas is taken with a micro-injector for chromatographic analysis. The solvent content (mg/kg) in the sample can be directly obtained from the standard curve based on the chromatographic peak height of the obtained sample. T Precision
The absolute difference between two independent determination results obtained under repeatability conditions shall not exceed 10% of the arithmetic mean. 85
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