GB 5009.224-2016 PDF EnglishUS$90.00 · In stock · Download in 9 seconds
GB 5009.224-2016: National food safety standard - Determination of trypsin inhibitor activity in soy products Delivery: 9 seconds. True-PDF full-copy in English & invoice will be downloaded + auto-delivered via email. See step-by-step procedure Status: Valid
Similar standardsGB 5009.224-2016: National food safety standard - Determination of trypsin inhibitor activity in soy products---This is an excerpt. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.), auto-downloaded/delivered in 9 seconds, can be purchased online: https://www.ChineseStandard.net/PDF.aspx/GB5009.224-2016 NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA National Food Safety Standard - Determination of trypsin inhibitor activity in soy products ISSUED ON: AUGUST 31, 2016 IMPLEMENTED ON: MARCH 01, 2017 Issued by: National Health and Family Planning Commission of the People's Republic of China Table of ContentsForeword ... 3 1 Scope ... 4 2 Principle ... 4 3 Reagents and materials ... 4 4 Instruments and equipment ... 6 5 Analysis steps ... 6 6 Expression of analysis results ... 8 7 Precision ... 9 8 Other ... 9 Annex A Dilution plan for sample extract ... 10 National Food Safety Standard - Determination of trypsin inhibitor activity in soy products1 ScopeThis Standard specifies determination method for trypsin inhibitor activity (TIA) in soy products. This Standard is applicable to determination for trypsin inhibitor activity in soy products.2 PrincipleTrypsin can react with benzoyl-L-arginine-p-nitroanilide (L-BAPA) to form p- nitroaniline. This substance has characteristic absorption at 410 nm. Trypsin inhibitor activity in soy products can inhibit this reaction to decrease absorbance value. The degree of decline is proportional to the trypsin inhibitory activity. Use spectrophotometer to determine absorbance values before and after this reaction at 410 nm. Quantitatively analyze trypsin inhibitor activity.3 Reagents and materialsUnless otherwise stated, reagents used in this method are analytically-pure and water is grade-three water specified in GB/T 6682. 3.1 Reagents 3.1.1 Hydrochloric acid (HCl). 3.1.2 Glacial acetic acid (CH3COOH). 3.1.3 Sodium hydroxide (NaOH). 3.1.4 Calcium chloride (CaCl2·2H2O). 3.1.5 Trypsin: freezing storage at -20°C. 3.1.6 Benzoyl-L-arginine-p-nitroaniline (L-BAPA). 3.1.7 Tris [NH2C(CH2OH)3, Tris]. 3.1.8 Dimethyl sulfoxide (C2H6OS, DMOS).4 Instruments and equipment4.1 Visible spectrophotometer. 4.2 Analytical balance: resolutions are 0.01 g, 0.001 g, 0.0001 g respectively. 4.3 PH meter: precision is 0.05. 4.4 Centrifuge: speed ≥4000 r/min. 4.5 Vortex oscillator. 4.6 Constant-temperature water bath: precision is ±0.1°C.5 Analysis steps5.1 Sample preparation For powder sample, take at least 200 g of representative sample. Fully mix for use. For bulk or granular sample, take at least 200 g of representative sample. Crush to below 425 μm. Fully mix for use. Avoid sample is over-heated during crushing process. 5.2 Sample extraction Weigh 1g ~ 10g (to the nearest of 0.001 g) of well-prepared sample (5.1) in a 100 mL conical flask. Add 50 mL of 0.01 mol/L sodium hydroxide solution. Mix well. Use 1 mol/L hydrochloric acid solution and 0.1 mol/L hydrochloric acid solution to adjust pH to 9.5±0.1. Place in a 0°C~4°C refrigerator for 15h ~ 24h. Take sample extract out and place at room temperature. Transfer to a 100 mL volumetric flask. Use water to set volume to scale. Shake well. After 15 min of precipitation, as required, dilute sample extract. Dilution depends on the expected TIA value of sample. Store extract in a 0°C~4°C refrigerator. It can be stored for 1 d. 5.3 Dilution of sample extract Refer to dilution plan in Table A.1 of Annex A. Dilute sample extract into three different dilution concentrations. Ensure that at least determination result of one TIA value in three inhibition percentages is within 40%~60%. If three determination results are not within this range, it needs to change dilution for re-determination. 5.4 Determination of trypsin use solution activity L-BAPA solution (3.2.11) 5 5 5 5 Sample dilution solution (5.3) 0 0 1 1 Water 3 3 2 2 Acetic acid solution (3.2.5) 1 0 1 0 Use vortex oscillator (4.5) to mix solutions in centrifuge tubes well. Place in 37°C constant-temperature water bath (4.6). Insulate for 10 min. Respective add 1 mL of trypsin use solution (3.2.9) into four centrifuge tubes. Use vortex oscillator to mix solutions in tubes well. Put test tubes back into constant-temperature water bath (4.6). Insulate in 37°C water bath for 10min±5s. Add 1 mL of acetic acid solutions (3.2.5) into standard tube and sample tube. Mix well. Place centrifuge tube in centrifuge (4.4). Perform centrifugation at a speed of 4000 r/min for 10 min. Use visible spectrophotometer (4.1). At a wavelength of 410 nm, use 10 mm cuvette, use water to perform zeroing. Determine supernatant absorbance. This solution can remain stable within 2 h.6 Expression of analysis results6.1 Inhibition rate of sample extract Inhibition rate of sample extract is calculated according to formula (1): Where, i - inhibition rate; Ar - absorbance of standard solution; Abr - absorbance of standard blank solution; As - absorbance of sample solution; Abs - absorbance of sample blank solution; 100% - conversion factor. 6.2 Trypsin inhibitor activity ......Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al. Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of English version of GB 5009.224-2016 be delivered?Answer: The full copy PDF of English version of GB 5009.224-2016 can be downloaded in 9 seconds, and it will also be emailed to you in 9 seconds (double mechanisms to ensure the delivery reliably), with PDF-invoice.Question 2: Can I share the purchased PDF of GB 5009.224-2016_English with my colleagues?Answer: Yes. The purchased PDF of GB 5009.224-2016_English will be deemed to be sold to your employer/organization who actually paid for it, including your colleagues and your employer's intranet.Question 3: Does the price include tax/VAT?Answer: Yes. Our tax invoice, downloaded/delivered in 9 seconds, includes all tax/VAT and complies with 100+ countries' tax regulations (tax exempted in 100+ countries) -- See Avoidance of Double Taxation Agreements (DTAs): List of DTAs signed between Singapore and 100+ countriesQuestion 4: Do you accept my currency other than USD?Answer: Yes. www.ChineseStandard.us -- GB 5009.224-2016 -- Click this link and select your country/currency to pay, the exact amount in your currency will be printed on the invoice. Full PDF will also be downloaded/emailed in 9 seconds.How to buy and download a true PDF of English version of GB 5009.224-2016?A step-by-step guide to download PDF of GB 5009.224-2016_EnglishStep 1: Visit website https://www.ChineseStandard.net (Pay in USD), or https://www.ChineseStandard.us (Pay in any currencies such as Euro, KRW, JPY, AUD).Step 2: Search keyword "GB 5009.224-2016". Step 3: Click "Add to Cart". If multiple PDFs are required, repeat steps 2 and 3 to add up to 12 PDFs to cart. Step 4: Select payment option (Via payment agents Stripe or PayPal). Step 5: Customize Tax Invoice -- Fill up your email etc. Step 6: Click "Checkout". Step 7: Make payment by credit card, PayPal, Google Pay etc. After the payment is completed and in 9 seconds, you will receive 2 emails attached with the purchased PDFs and PDF-invoice, respectively. Step 8: Optional -- Go to download PDF. Step 9: Optional -- Click Open/Download PDF to download PDFs and invoice. See screenshots for above steps: Steps 1~3 Steps 4~6 Step 7 Step 8 Step 9 |
