This standard specifies the method for determining cholesterol in various animal foods using a spectrophotometer. This standard is applicable to the determination of cholesterol in various animal foods. GB/T 5009.128-2003 Determination of cholesterol in food GB/T5009.128-2003 Standard download decompression password: www.bzxz.net

IC8 67.040
National Standard of the People's Republic of China
GB/T5009.128-—2003
Replaces CB/T15206—1994
Determinatiun of chulesterin in foods Issued on August 11, 2003
Ministry of Health of the People's Republic of China
Standardization Administration of the People's Republic of China bzxz.net
Implementation on January 1, 2004
G8/T5009.128--2003
This standard replaces G/T15216--1994 Method for determination of cholesterol in foods. Compared with GB/T18206--1994, the main changes of this standard are as follows: The Chinese name of the standard is changed to Determination of cholesterol in foods. -- GB/T200C1.4--2001 Standard Part 4: Chemical analysis methods is revised to improve the structure of the original standard.
This standard is issued and managed by the Ministry of Health of the People's Republic of China. The technical unit responsible for this standard is China Institute of Medical Science, Nutrition and Food Hygiene. The main drafters of the standard are: Wang Chunzhuang, Xian Jian, Shi Bi, Fan Wenyu, The original standard was first issued in 1, and this is the first time. 126
Determination of cholesterol in food
This standard specifies the practical method for determining the cholesterol content in various animal foods by spectrophotometer. This standard is applicable to the determination of cholesterol content in various animal products. 2 Principle
GB/T5009.128--2003
When sterols and sugars can be used together, the negative substances can be decomposed and the synthesis should be tested. The high-quality samples can be extracted and saponified first, and the acid content can be used as a trace to determine the content of food in the medium term. 3 Test tree
3.1 Stone movement.
3.2 No group B.
3.3. Concentration.
3.4 ​​Glacial acetic acid.
3.5 Phosphoric acid.
3.6 Cholesterol standard solution.
3.7 Cholesterol standard solution (1112/ml): Dissolve 1000g of cholesterol in glacial acetic acid and dilute to 100213. This should be kept for at least 2 months.
3.7.2 Filter alcohol standard (100g/ml). Absorb 1 ml of standard solution. Make up to 100ml with glacial acetic acid. Prepare temporary
3.8 Iron colorimetric reagent.
3.8.1 Preparation of vanadium reduction: decompose 1161% sulfuric acid with HeNH(SO3):H0 in 1U0ml.85% phosphorus in a handheld combustion chamber, fully stabilize in a room temperature,
3.8.2 Preparation of vanadium reduction, absorb 10ml of the preparation solution and make up to 100l with concentrated water, in a dryer, dissolve in 590% potassium chloride with 3.9% enzyme absorption water, and dilute to 1.3.10 Compound sodium hydroxide (50/1): weigh 5g sodium oxide, dissolve in 100ml sodium hydroxide, and dilute to 100ml.3.11 Solution bottle oxygen: 1% %.
4 Receiver
4.1 Equipment required for the experiment.
4.2721 Spectrometer.
4.3 Electric heating plate,
4. Electric vibrator,
,5. Sealed test tube: volume 10mL.25mL.5. Analysis steps
5.1. Pipette standard alcohol solution D.3, 3.5, 1.0, 1.5, 2.m. into 10mL test tubes respectively, add 131
GA/5003.28--2003
heat volume up to mL, and insert into the rapid plate liquid along the general, at 550Jmt-575TE within 15min~mxn, colorimetric, and use cholesterol standard as the model Single standard, the noise intensity value is the coordinate curve after standardization: 5.2 Determination
5.2.1 Extraction and determination of food fat
According to the type of food, use the method of extracting fat separately, grind and grind the fat and calculate the content of fat in 100% of the food.
5.2.2 Determination of food cholesterol
Put 3-4 drops of lightly extracted fat (containing about 300g~500ug) in 1.5mL or 1.5mL tube, record its mass accurately, add 4mL ethanol, 0.5mL 55g/L potassium hydroxide, and saponify in a constant temperature water bath at 65℃ for 1h. During the saponification, use the deionized water every 2min-3min. After the chemical reaction is completed, take out the test tube, add 3mL of 50/L potassium cyanide solution, 10mL of non-ethanol, and incubate on an electric vibrator for 2 hours. Stratification usually takes about 1 hour. Add 2mL of ether and place under 1mL. Mix well. Collect with hydrogen in water, add 4L of ethyl acetate, 2 mL of colorimetric solution, and obtain the absorbance of 5-575mL under a colorimetric temperature of 15 minutes. Put it in a standard bag containing the corresponding alcohol.
6 Calculation of results
Calculate according to the following formula:
Wherein:
XAXyLxe
——Cholesterol content in the sample, unit is mg/cg; A——The absorbance value of the measured value on the cholesterol standard line is μg (μg); V
——Total volume of petroleum aldehyde, unit is L (L); Volume of petroleum aldehyde, unit is 100g (g10); 1
New calculation is made into grams.
The determination results are expressed to the minimum effective point.
7 Precision room
The absolute difference between two independent determination results obtained under basic conditions shall not exceed 10% of the technical mean value, 138
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