GB/T 23890-2026Determination of erucic acid and glucosinolates in rapeseed (English PDF)

4.2 Instruments and Equipment

4.2.1 Near-infrared analyzer It meets the requirements of GB/T 24895.

4.2.2 Working Environment Temperature 15°C~30°C, relative humidity 20%~80%.

4.3 Sample Preparation

4.3.1 Sampling and subsampling shall be performed in accordance with GB 5491.The calibration model samples should cover the content range of erucic acid and glucosinolates, and the number of samples should be no less than [number missing]. There are 100.

4.3.2 The moisture content of rapeseed samples should meet the requirements of GB/T 11762.

4.4 Calibration Model Establishment and Verification

4.4.1 Spectral Acquisition Take an appropriate amount of rapeseed sample and measure it using a near-infrared analyzer. Each sample should be prepared three times. After each measurement, the sample should be compared with... The original sample to be tested was mixed thoroughly, and a new sample was taken for the next measurement. The calculated average spectrum was used as the sample measurement spectrum.

4.4.2 Determination of Chemical Values During the same period of spectral acquisition, the contents of erucic acid and glucosinolates were determined according to the methods specified in GB 5009.168 and NY/T 1582.

4.4.3 Calibration Model Establishment A calibration model for erucic acid and glucosinolates was established using chemometric methods, and the calibration model was validated in accordance with GB/T 29858.

4.4.4 Calibration Model Upgrade Periodically select representative or anomalous samples to add to the calibration model sample set, re-establish the calibration model, and complete the calibration after validation. Model upgrade.

4.5 Sample Determination

4.5.1 Measurement Method The average spectrum of the samples was acquired using the method described in 4.4.1, and each sample was collected twice. The mustard color was determined using the calibration model established in 4.4.3. Content of acid and glucosinolates.

4.5.2 Result Processing and Representation The absolute difference between the two measurements should meet the requirements of 4.6.1.The arithmetic mean of the two independent measurements should be taken as the measurement result, and the result should be kept consistent. Leave one decimal place.

4.5.3 Confirmation and handling of abnormal measurement results

4.5.3.1 Confirmation of Abnormal Measurement Results The following are all considered abnormal measurement results.

---The measured results exceeded the range of erucic acid and glucosinolate content covered by the calibration model;

---The absolute difference between the two measurements does not meet the requirements of 4.6.1.

4.5.3.2 Handling of Abnormal Measurement Results Abnormal samples that exceed the calibration model range should have erucic acid and glucosinolates determined according to the methods specified in GB 5009.168 and NY/T 1582, respectively. Samples whose content and results match those obtained by near-infrared spectroscopy can be used for calibration model upgrades. For abnormal samples where the absolute difference between two measurements does not conform to section 4.6.1, the spectral data and calibration model prediction results should be retested. Samples whose absolute difference between two retests meets the requirements of

4.6.1 can be used for calibration model upgrades.

4.6 Repeatability and Reproducibility

4.6.1 Repeatability In the same laboratory, by the same operator using the same instruments and equipment, the same samples were resampled and repacked within a short period of time to analyze the same... The samples to be tested are tested independently of each other, and the specific requirements for the absolute difference between the two independent measurements are shown in Table 1.

4.6.2 Reproducibility In different laboratories, by different operators using different equipment, the same sample was tested using the same method, with two independent measurements. The specific requirements for the absolute difference of the results are shown in Table 1.

5.1 Principle

5.1.1 Principle of Erucic Acid Determination The turbidity formed in polyethylene glycol octylphenyl ether ethanol solution varies depending on the erucic acid content in rapeseed oil. This turbidity is related to the erucic acid content. The correlation between quantities was used to determine the erucic acid content.

5.1.2 Principle of glucosinolate determination Glucosides in rapeseed react with Aspergillus oryzae thioglycoside hydrolase to generate thioglycoside degradation products, which then react with o-toluidine ethanol solution to generate characteristic... The content of glucosinolates in the colored products of the absorption peaks was determined by spectrophotometry.

5.2 Reagents Unless otherwise specified, all reagents are of analytical grade.

5.2.1 Water. GB/T 6682, Grade II.

5.2.2 Ultrapure water. GB/T 6682, Grade 1.

5.2.3 Polyethylene glycol octylphenyl ether (C34H62O11).

5.2.4 Ethanol (C2H5OH). >99.5%.

5.2.5 Potassium dihydrogen phosphate (KH2PO4).

5.2.6 Aspergillus oryzae thioglycoside hydrolase.

5.2.7 Phosphoric acid (H3PO4).

5.2.8 o-Toluidine (C14H16N2).

5.2.9 Polyethylene glycol octylphenyl ether solution (10 mg/mL). Weigh

10.0 g of polyethylene glycol octylphenyl ether (5.2.3), and use ethanol (5.2.4) Dissolve and bring the volume to 1000 mL.

5.2.10 Potassium dihydrogen phosphate solution (

0.1 mol/L). Weigh

1.36 g of potassium dihydrogen phosphate (5.2.5), dissolve in water (5.2.1), and dilute to the specified volume. 100mL.

5.2.11 Aspergillus oryzae glucosinolate hydrolase solution (

0.5 mg/mL). Weigh

5.0 mg of aspergillus oryzae glucosinolate hydrolase (5.2.6) and dissolve it in ultrapure water (5.2.2). Dissolve and dilute to 10 mL.

5.2.12 Buffer solution with pH 6.0.Transfer

1.0 mL of potassium dihydrogen phosphate solution (5.2.10) and

4.0 mL of aspergillus oryzae glucosinolate hydrolysate, respectively. Mix the enzyme solution (5.2.11) with water (5.2.1), adjust the pH to

6.0 with phosphoric acid (5.2.7), and store at 4°C for later use.

5.2.13 O-Toluidine solution (

0.62 mg/mL). Weigh

0.62 g of o-toluidine (5.2.8), dissolve it in ethanol (5.2.4), and dilute to the final volume. 1000mL, stored in a brown bottle, refrigerated at 4°C, shelf life 7 days.

5.2.14 Rapeseed glucosinolate assay plate. Use a 96-well plate, add 20 µL of pH

6.0 buffer solution (5.2.12) and 10 µL of ortho- and hydroxylamine to each well. Toluidine solution (5.2.13), for later use.

5.3 Instruments and Equipment

5.3.1 Microplate photometer. Halogen tungsten lamp wavelength. 450nm±10nm, repeatability. -0.5%~0.5%, stability. < 0.005Abs, linear... Sexuality. -1%~1%.

5.3.2 Fat preparation apparatus. see Appendix A.

5.3.3 Micro pulverizer.

5.3.4 Constant temperature chamber. 32°C±0.5°C.

5.3.5 Balance. sensitivity is 0.01g and 0.1mg respectively.

5.3.6 Pipettes..200µL, 1000µL.

5.4 Sampling Perform in accordance with GB 5491.Foreign impurities should be removed from the sample during sampling.

5.5.1 Erucic acid determination

5.5.1.1 Place the quartz cuvette and 20 mL of ultrapure water (5.2.2) in a constant temperature incubator (5.3.4) before preheating to a constant temperature.

5.5.1.2 Take 5g~8g of rapeseed (5.4) and pour it into a fat preparation apparatus to prepare an oil sample. Collect the sample with an oil collection tube and let it stand for later use.

5.5.1.3 Weigh

0.30 g (accurate to

0.01

g) of oil sample into a 50 mL Erlenmeyer flask with a stopper, and add 25 mL of polyethylene glycol octyl ester using a pipette. Phenyl ether solution (5.2.9), tighten the stopper, shake vigorously to mix thoroughly, and then place in a constant temperature incubator (5.3.4) for 15 minutes.

5.5.1.4 In an incubator, use a pipette (5.3.6) to transfer 1000 µL of ultrapure water (5.2.2) kept at 32°C into an Erlenmeyer flask, adding dropwise... Shake the Erlenmeyer flask, tighten the stopper, and shake well. Then pour the mixture into a quartz cuvette and determine the erucic acid content using a microplate spectrophotometer (5.3.1). The measured value... This refers to the erucic acid content of rapeseed.

5.5.2 Determination of glucosinolates

5.5.2.1 Take 3g~5g of rapeseed sample (5.4), grind it with a micro grinder or mortar and pestle until it all passes through a 0.425mm pore size test aperture. Sift, for later use.

5.5.2.2 Weigh

0.50 g (accurate to

0.01

g) of the sample and place it in a 5 mL stoppered test tube. Add 3 mL of water (5.2.1) using a pipette and seal the tube tightly. Mix thoroughly and let stand at room temperature for 8 minutes.

5.5.2.3 Filter with defatted cotton or centrifuge (3000 r/min) for 5 min, and add 50 µL of the supernatant to the well of the glucosinolate test plate (5.2.14). Within 8 minutes, the reaction was allowed to proceed. Then, 150 µL of potassium dihydrogen phosphate solution (5.2.10) was added using a pipette (5.3.6), and the reaction was allowed to proceed for another 2 minutes.

5.5.2.4 For the determination of glucosinolates using a microplate spectrophotometer, after blank calibration and zeroing, the measured value is the total glucosinolate content per gram of rapeseed meal or per gram of rapeseed. Micromoles (µmol/g). The same sample was measured twice, and the arithmetic mean of the results was taken, with the result retained to one decimal place.

5.6 Precision

5.6.1 Erucic acid When the erucic acid content is greater than 5%, the absolute difference between two parallel determinations should not exceed 1.0%; when the erucic acid content is less than or equal to 5%, the absolute difference between two parallel determinations should not exceed 1.0%. The absolute difference in the test results should not exceed 0.5%.

5.6.2 Glucosides The absolute difference between two parallel determinations of glucosinolate content in oilseed cake should not exceed 8.0 µmol/g. The absolute difference between two parallel determinations of glucosinolate content in rapeseed is no greater than 4.0 µmol/g.

5.7 Limit of Detection The detection limits for this method are. 0.5% for erucic acid and 10 µmol/g for glucosinolates. GB/T 23890-2026. Determination of Erucic Acid and Glucosides in Rapeseed ICS

14 National Standards of the People's Republic of China Replaces GB/T 23890-2009 Determination of Erucic Acid and Glucosides in Rapeseed Published on 2026-03-

31 Implemented on October 1, 2026 State Administration for Market Regulation The State Administration for Standardization issued a statement.