GB/T 5009.89-2003 Determination of niacin in foods

This standard specifies the determination of niacin content in food by microbiological method. This standard is applicable to the determination of niacin in various foods. The detection limit of this method is 10ng, and the linear range is 0.05μg～0.3μg. GB/T 5009.89-2003 Determination of niacin in food GB/T5009.89-2003 Standard download decompression password: www.bzxz.net

ICS.67.040
National Standard of the People's Republic of China
GB/T5009.89—2003
H23—1990
Determinatinn of niacin in food foods2003-08-11 issued
Ministry of Health of the People's Republic of China
National Standardization Administration
2004-01-01 implementation
GB/T5009.89-2003
This standard corresponds to A0AL43.17--13.174 Bioassay of Smoke Energy in Foods (1984 edition: This standard is not equivalent to A0AC43.167~3.174
This standard replaces GT1233-190 Determination of Smoke Energy in Foods 3. Compared with this standard number GB/T123951990, the main changes are as follows: 1. The Chinese name of the standard is modified. The Chinese name of the standard is For the determination of nicotinic acid in food; according to G3/10, 4-2≤ standard part 4: Chemical analysis method 8, the structure of the original standard is revised:
This standard is proposed by the Ministry of Health of the People's Republic of China. The originating units of this standard are the Chinese Academy of Preventive Medicine and the Institute of Food Hygiene. The main drafters of this standard are: Wang Guangya, Li Xiaolin, Shen Xiang, Shi Lao, Xiaojie. The original standard was first issued in 1, and this is the first revision. 4f
1 Scope
Determination of nicotinic acid in food
This standard stipulates the use of microbial method to determine the content of nicotinic acid in food: This standard is applicable to the determination of nicotinic acid in food of various days. The detection limit of this method is 10. Line Empire.\g.3g2 Principle
G/T 5009.89—2003
The growth of microorganisms is essential for the growth of bacteria. For example, 1-5% of this vitamin is required for growth. The lack of this vitamin in the culture medium will cause the bacteria to grow abnormally. Under certain conditions, the growth rate of the bacteria and the production of its metabolites are proportional to the content of this vitamin in the culture medium. Therefore, the content of the sample acid can be determined by the determination of the concentration of the sample acid. 3 Reagents
3.1 Extraction,
3.23/T acid concentration.
3.32.1mnl/T hydrochloric acid solution. www.bzxz.net
3.43.5mol/L flow rate, first fill a 20cc cup with 70ml of water. Add 2mT of standard acid solution to the water. Use not required, 3.5t.u2u./T. ice z aldehyde liquid, 3.61cnal/1. Hydroxybenzoic acid liquid. 200 sodium hydride in 100 ml of sodium hydride 539mL 3.7! aol/L sodium hydride, sodium hydride in water, dilute to 1ml, 3.825 volume fraction ethanol. 3.9 cheese slices, different requirements, 3,9.1 Preparation of aldehyde-free protein, 3.9.1.1 Ethanol treatment, weigh 19 ethanol in a dry bottle, add 00m. ethanol in water, heat at the same time, vacuum extract, discard the wave, add ethanol, repeat 3 to 4 times, select solid or colorless, take out and dry in an oven.
3.9.1.2 Magnetic sedimentation, weigh 250ml of strong white, stomach "5I Rui towel, slowly add 5, 1, water or I, add 2.77m/1 of isocyanate, then soak for 3min. Use a siphon to remove the supernatant, add 1.GI water, add 2.77m/1 of isocyanate, after 8 cycles, add 3.1% water, add 55.t.12r.011 water, overnight to make the egg white become slurry again. Then filter: slowly add 5)I3m/1 of salt to the liquid, remove [H.3. Make the cheese completely precipitate, then filter. Remove the filtrate, rinse several times with 50% hot water, remove the acid by pressure, add 500 μl of phenolic acid (excluding vitamins), add 200 μl of 50% sodium hyaluronate, and hydrolyze under pressure steam at 10×10Pa. Transfer the hydrolyzate to a hot water bath and evaporate it in a filtered water bath until it becomes a paste. Repeat this process to remove the acid. Note that each evaporation should not cause any charring or burning. Adjust the pH to 3.5 with sodium hydroxide. Use acetic acid blue as an external indicator, add 23% sodium hydroxide, and filter. If the effluent is not light or colorless, treat it with activated carbon. Dilute the concentrate with water to 500ml, add a little methanol and store in ice. 3.11 Raw water: mix 1000g sodium chloride solution, use for 6-8 hours, add 10ml and then add about 10l. Standard pressure: 6.9×P/min, keep aside. 3.12 Hydrogen phosphate concentrate, take No. 4 L-lysine and 121.5g sodium sulfoxide, put into 600ml water, heat to 70%~-80℃, add gradually. 2.4/Stir constantly until all the solution is dissolved, cool to room temperature, dilute the sample with water to 10 (1m). Add a little benzene and keep in the refrigerator.
3.13 Biochemical reagent: urea, chloramine, sulfuric acid, guanidine, 2ml concentrated test reagent, then heat to dissolve completely, cool, if there is a precipitate, add benzene, which can be heated, if there is a reaction: add water to cool, add a little armor and keep in the refrigerator. 3.14 [Pantothenic acid, pyridoxine hydrochloride solution: weigh 100 mL of pantothenic acid and 100 mL of pyridoxine hydrochloride, dilute with water to 1000 mL each of basic acid and pyridoxine hydrochloride, place this solution in a brown reagent bottle, add a little acetonitrile and store in a refrigerator, 3.15 [Pantothenic acid, 100 mL of 1.2 mol/L acetic acid, take this solution and add 100 mL of flavonoids and 10% indole, mix well and incubate at 22°C, add a little acetonitrile and store in a refrigerator. This reagent should be stored in a brown bottle to prevent flavonoids from being damaged by light.
3.1 Salt solution: weigh 2g of potassium dioxygen iodide (HP>) and potassium iodide (KTI-P), add water to dissolve and dilute to mL. Add about 10% ethyl acetate (M%) and store in refrigerator.
3.17 Ethyl acetate solution: weigh 10% ferrous metal (M%) 0.7H2O, 0.2% ferrous acid (FeS7I[,0]) and C.5% ferrous metal (MS), dissolve in water to 0.3ml. Add 5 drops of ethyl acetate and store in refrigerator. 3.15 Standard disinfectant (0.1g/mL): accurately weigh 50.01:1 solution of 1% ethyl acetate and set the detector to dryness, then store in refrigerator. 3.19 standard liquid of niacin (1g/1:1.): Pipette 1.00ml niacin standard reserve bag and place it in a 100ml bottle, add H25 and 2% suspended liquid, and filter it into the equivalent of 1% nicotinic acid. 3.2 Smoke number standard method minus (U. "/m), when used and take 5.) simmered acid standard liquid into) m, put it in a volumetric bottle, add water, limit: rate per parent and equivalent, 1 3.21 base 2 benzene preparation: mix the following in 5ml. Wood to 450 proof 10mol. Adjust the sodium chloride rate to 6.9. Use the limit car benefit as the indicator. The screen rate is 533ml, the acid body is slightly straight
cysteine ​​glass, tryptamine warm wave
serve De cold, and Ling, home after other sensitive
[pan-transmitted calcium, Liu to base benzene, tooth enough alcohol Ping Sen cough female state, point acid before acid decline, biotin drop liquid methyl salt drop hoop
ethyl benefit swim liquid
no rat shop
wan seek the beautiful neighbor| |tt||3.22 Agar culture medium: prepare the following formula: 1.3 ml of water, add water to 1 ml of water until the agar is completely thick, take the total amount of adsorbent as the external reference. Use 1m/1.5 ml of hydrochloric acid to adjust the temperature as soon as possible, put 4 tubes 3~5Tu, cover with cotton wool, sterilize with steam at 6.910P, heat under pressure for 1min, take out and gently cool the test tube to room temperature, store in a refrigerator,
Anhydrous sodium acacia [
Biochemical reagents
Fermentation extract (bacterial test kit)
Acetic acid
Agar (bacterial culture)
GB, T 5009.89—2003
3.231g/part ethanol solution, weigh 5.1 flow resistant monitor, use it again (1+3> after deep solution. Then add ethanol to dilute to 1CCmL: 3.24.1/L glandular herb solution: weigh 0.1g of the blue of the herb into a small grinder, 1.6m0.1uol/L oxygen oxidation, small water grinding, until the solution is complete add 250ml3.250.4:L dilute solution. Transfer 0.1g of oxygen in a small mortar, add 1.4ml.t, 1 mol/1.4% hydrogen peroxide, add some water and continue grinding until the solution is complete. 230ml3.26% dilute cheese sound. 0]R/. Drop into the pool, measure 25ml.1.4g/L of enzyme blue water to 10L for use in the collection room with equipment. 4. 2 Electric heating 1 Yi training system recommended.
4.3 Steam eliminator,
4. Filter,
1.5 Centrifuge,
4.6 Hard solution test, 2ummxl0mm
5 Preparation and preservation of bacteria and culture solution
5.1 Preparation of bacteria: Inoculate arachidonic acid bacteria (called ATV31) in 2 or more beds of fat culture, keep in a constant temperature cage at 16~245℃, take out and use in the refrigerator for 1 year: If the two samples are not prepared, they cannot be used to prepare the inoculum. Before use, the samples should be prepared once for two consecutive days before payment.
5.2 Preparation of the culture medium: add 5L.1/ml nicotinic acid standard and m1.1/ml phenyl benzoate solution to 1ml of each sample, sterilize at 6.×Pe for 15 hr, collect and store in the refrigerator. Prepare 2 to 1 tube each time, and use each tube for analysis.
6. 1 Preparation of inoculum
The day before yesterday, transfer 1 seed medium to a sterilized culture medium. Keep in a humidified box at 37 ± 0.5 SH--24h. Take out and rinse twice with saline solution, centrifuge at 33)r/min, and then mix in a mixer at 100 °C. Add the mixture to a sterilized syringe and add the mixture to the standard solution. The method is as follows
6.2 Preparation of test sample
Weigh 55% of the acid-containing solution from the test sheet 9.29) to 10) using a 1/1000 scale and place it in a 100ml bottle. Add 50ml of 0.5m01/ml of water and cool to room temperature at 10.310 °C for 50min. Use:! 1.5 ml: 1.5% hydrogen peroxide, and use the flask as the external index. Transfer the hydrolyzate to a 1cc ml volumetric bottle and add all the contents. For samples with high fat content, use 7.5% ether to remove esters. This sample solution can be stored in a 4-well box. Add 25l of water, adjust the pH to 1.5, and use 1ml/1.5% ethanol as the external index. The content of the solution is about 6.3%. The test solution is prepared by adding 1.2, 4.0 ml of the two test solutions into test tubes respectively. Two groups of test solutions need to be prepared. Add water to each tube to dilute to 5ml. Add 5ml of culture medium. GB/T5009.8$-2093 6.4 Preparation of standard tubes Add 0.0.5, 1.0, 2.5, 2.0, 2.5 and 3.0ml of warm standard solution to each test tube respectively. Add water to each tube to dilute to 5ml. Add 5ml of HCl to the local culture medium reserve pool. Sterilize the test tubes and standard tubes with sterilization tubes. Inoculate and culture with 5.9×10 bacteria at 150°C. Wait until the test tubes are cooled to room temperature and the tubes are sterilized. Place in a 37+0.3 incubator at about 72°C. 6.7 Titration
Put the culture medium in the test tube into a 100 ml triangle, drip the wash solution into the negative plate twice with 0.1 μl/L hydrogen peroxide, and titrate with 0.1 μl/L hydrogen peroxide. The green mark is the integer, and its value is about GH. Calculate the result
X=F10)
Where:
Nicotinic acid content, unit is g/;
---·Open the sample and cover the neutral content The unit is grams per liter (mI). Solve the limit volume, which is ml. The F formula is the concentration of the test solution. The unit is grams per liter (ml). The precision coefficient is calculated to express the result of the calculation of the half mean of the two independent determination results obtained under repetition conditions. The absolute difference between the results shall not exceed the arithmetic half mean, r.44.The number of the solution of formula F is expressed as g: ...The number of the solution of formula F is expressed as g: ...
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.