GB/T 5009.46-2003 Analytical methods for hygienic standards of milk and dairy products
Some standard content:
ICS 67.040
National Standard of the People's Republic of China
GB/T5009.46-—2003
GB06—556
Method of analysis of hygienic standard of milk and dairy products
2003-08-11 Issued
Ministry of Health of the People's Republic of China
National Administration of Standardization of the People's Republic of China
2004-01-01 Implementation
GB/T5009.46—2003
This standard replaces GB/T75009.46—1≤SGs Method of analysis of hygienic standard of milk and dairy products Compared with GB/T50946-1596, the main changes of this standard are as follows: It is modified according to the structure of GB/T 200G7.4-2 "Standard Rules for Part 1 Chemical Analysis Methods". This standard was proposed by the Ministry of Health of the People's Republic of China and was drafted by Heilongjiang Provincial Health and Prevention Station, Shanghai Food Industry and Health Inspection Institute, and Food and Health Inspection Institute of the Ministry of Health. This standard was first issued in 1985 and revised for the first time in 1985. This is the first revision. 1 Scope Milk and lactic acid Analytical methods for hygienic standards of milk and dairy products This standard specifies the analytical methods for various hygienic indicators in milk and dairy products. This standard applies to the analysis of various hygienic indicators in milk and dairy products. 2 Normative referenced documents
GB/T5009.46—2003
The following items are applicable to the clauses of this standard through reference to this standard: The referenced documents with the date indicated, all subsequent contents excluding amendments or revisions are not applicable to this standard, however, the latest versions of the documents that have been reached based on this standard may be obtained soon. If the date of the referenced document is not indicated, the latest version is applicable to this standard. H5009. Determination of lead in food
GB/T5009.7 Determination of final raw materials in food
GB/T5009.8 Determination of small amounts of sugar in food
G5/T009.12 Determination of lead in food
1009,1% Determination of copper in food
G/F5009,1% Determination of required product
GB/T 3009. 17 Determination of total and organic content in food
B/T 500U.1
The content of 666 in food, simple drip, sterilized milk
Applicable to pasteurization and other processes for sterilization and sterilization of milk, each sub-process index is set, 3 sensory inspection
According to the requirements of relevant sterilization and sterilization sanitation standards: 4 Physical and chemical examinationbZxz.net
4.1 Relative concentration
This standard defines the concentration as the mass ratio of milk to volume of water. 4.1.1 Instrument
4.1.1.1 There are two types of sterilizers: 24℃ and 5℃1. The results obtained by the former and the latter are based on 24.1.1.2 Glass or 200mL-25t dish Before: The length of the meter should be large enough to fill the milk. When the sample is mixed and adjusted to 1025 (the volume is 25) ml, the sample should be filled to 3/3 of the volume. Do not allow the sample to form a pool and measure the sample temperature. Carefully sink the milk into the sample at 3\ of the scale, and then make sure that it floats spontaneously, but cannot be connected with the sample. After 3 to 3 minutes, spray the milk at the same temperature as the sample: the effective value is determined by the temperature of the milk meter and the value in Table 1. Relevant formula (with the scale of the meter): X = <*:1.000: × : 000
GB/T5Q09.46-2D03
X—Emulsion number
: hope——Phase density of sample
When using 20:℃: emulsifier, when the temperature is 21, substitute the reading into the formula (11 relative density) to calculate the day. If the measurement is not at 21, refer to Table 1 to convert it into 20 hours, and then substitute it into Formula 1 to calculate: when the temperature of the sample is 18, use 20/4 emulsion 1 reading 28, the relative width is 28, converted to 2 relative density, refer to Table 1 (18:, 25 reading) base is 27.5, the relative density at 2C℃ is 1.02. 4.2 Fat
4. 2. 1 Gottlieb-Rodriguez method
4.2.1.1 Principle
Use hydrogen peroxide to convert the calcium salt of protein in milk into soluble calcium salt to make the bound fat volatile, use acetaldehyde to extract fat from milk, dry to the desired value, weigh it to get the milk fat content, 4.2.1.2 Reagents
4.2.1.2.1 Chlorine water.
4.2.1.2.2 Ethanol.
4.2.1.2.3 Ethyl acetate.
4.2.1.2.4 Non-oil boiling point 3℃~℃. :4.2.1.3 Receiver
Oil cell: inner diameter 2. cmL~2.cm volume [(cmmL, see Figure 1. 4.2.1.4 Analysis steps
The whole section 10.Cml. Sample is aspirated and added with 25mL chlorinated water + fully filtered: heat in a 60° water bath for 5min and then shaken 2i. Add 10m alcohol, fully react, cool in cold water, add 25mL ethyl acetate, add 2il petroleum ether, 1 mmol/l for 0.5min, and place for 30min. When the layer becomes clean, take the fermentation volume. The aldehyde layer is transferred to a constant volume flask, transported to a constant volume, heat to reduce the ethyl acetate, place the flask at 98°C-100°C for 1 minute, then weigh it, and dry it at -100°C for 3 minutes. The difference between the two changes is not more than 1.3mg.
4.2. 1, 5 Results Calculate the content of the fetus in the process by reverse formula (2). X=135
In the formula:
is the content of the product, in g/100g; the quality of the flask, in g;
is the quality of the flask, in g:
is the sample volume (volume multiplied by the relative density of the agent), in g (g: V is the total volume of the acetylene layer taken, in L); the volume of the released acetylene is in mL. The calculation result should retain two significant figures.
4.2.1.6 Precision
The absolute difference between two independent determinations under the same conditions shall not exceed % of the arithmetic half-mean.
Two readings
4.2.2 Lambert method
4.2.2.1 Principle
1 The precision of the milk is converted from the measured value to the value of 20°C. Calculate the precision of the milk: 31, 711,5
23r 9:2-t-0
84r±24-6
3.2. 3131.:
24.6:25.1
GB/T 5009.45--2003
36.426.626.837.0
290232
29.220. 528. 7 3u. u|30.2
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34, 634.334, 4, 85. :,35. 3
5116.7:7:9
Add acid to the bovine milk to destroy the gelatinous substance of the cow milk and the protein membrane on the lipid globules. After centrifugation, measure the content of the lipid. 4.2.2.2 Reagents
4.2.2.2.1 Acid, relative density 1.823~1.254.2.2.2.2
4.2.2.3 Collection
4.2.2.3.1 Milk fat meter.
4.2.2.3.2 Yi Bo's milk fat meter: the minimum dosage value is 0.%. See Figure 2: 369
GB/T50C9.46—2003
4.2.2.4 Analysis steps
First add ml. into the milk fat meter, then follow the steps carefully to ensure that the sample is not mixed with the micro-sample. After the mixture is formed, add ten core skins Hold the knife in the palm of your hand to prevent impact. Shake vigorously until a uniform brown liquid appears. Let stand for several minutes with the bottle mouth facing upward in a water bath for 5 minutes. Take the milk fat and centrifuge it at 1500rpm for 5 minutes. Then centrifuge it in a water bath for 7 minutes. A layer of milk fat should appear on the surface of the water bath. Read the value immediately after 5 minutes. This is the average white fraction.
A.2.3 Babcock's method
System, test room 4.2.2. and 4.2.3.2. 4.2.3.1.1 Milk fat centrifuge
4.2.3.1.2 Bubcock milk bottle: see Figure 3. Figure 3
4.2.3.2 Steps
Accurately pipette 1.6L of sample and put it into a bottle of Bacon's milk. Then take 17.ml of acid and pour it into the bottle along the neck to make it fully absorb until it becomes a uniform brown liquid. Place the milk fat in a centrifuge at 1000./min for 5min. Add the above water to the base of the centrifuge and centrifuge for 2min. Place the centrifuge in a water bath at 80°C for 55-60 minutes. After that, take out the milk fat and read the result. Print the fat content. 1. 2. 4 Inesert alkali method
4.2.4.1 Principle
Time.2.2.1
4. 2. 2. 2 Reagents GR/T50C9.46—2003 4.2.4.2.1 Preparation: Weigh 15 g of hydrogen peroxide and add 200 ml of anhydrous water to dissolve. Take 7.5% sodium chloride and 10% water. Add water to reduce the mixture to 5 mL. Pass through with absorbent cotton and store in a bottle. 4.2.4.2.2 Mix with isocyanate to obtain (5.0 + 10.5). 3 Apparatus for analyzing milk fat: as shown in Figure 2, 4.2.4.4 Analytical steps: Take milk fat rate: carefully add 1 ml of concentrate, then add 1 nl of sample and 1 ml of ethyl acetate, stir with a special rubber bottle, shake carefully until foam is produced. Add 1 ml of water at 70-73 °C, shake carefully for 1 minute, wait for 10 ml to be taken out, turn it down, raise it to standstill in water for 10 minutes (minutes-1 minute), take out the fat layer and read the speed at which the bubbles disappear, which is the percentage of fat skin effect. 4.3 Disinfection effect test (phosphoric acid determination) 4.3.1 Principle: Raw milk is beneficial to the analysis of organic matter, which can slow down the reaction and reduce the viscosity of the whole milk. After the milk is digested, the phosphatase activity is increased. Under the same conditions, it cannot decompose organic phosphorus compounds. Sodium disodium phosphate is decomposed by phosphatase in alkaline solution to produce a blue color. The blue color is different from the color of the milk. The concentration of blue is related to the content of the milk. That is, the milk is not digested.
4.3.2 Reagents
4.3.2.14 Nature: 1 Alcohol: Boiling point, 115: ~1184.3.2.2 [Two reagents: weigh 11ml of 2.1i·2-hydroxy-2-oxo-1-butanone. Ethanol, put it in a color bottle and store it in ice for 1 year. Prepare
4.3.2.3 salt solution, weigh 25.47? Sodium borate (NH4+, 0H2O) is dissolved in 900 1/4 of water, 3.27 g of sodium borate or 31. = m sodium hydroxide solution (4 g) is diluted with water to (1/4). 4.3, 2.4 After washing, take out the double crystals of H2O: dilute with water in the sodium borate solution, prepare the tablets for clinical use
4.9.3 Analysis step
Absorb c5ml. Test column, bone belt test, 5ml. Rinse the liquid and shake for 3 minutes to 4 minutes. Then add 10ml of water-soluble or culture cream. Then add the reagent. If the blue color appears after 5 minutes of incubation, it means that the disinfection treatment is not enough. It is a potential desensitization. After 2 minutes of incubation, turn the tube over completely, rotate it 4 times to stop the bubble bursting, and then count the pressure results and do the self-test at the same time.
4.4 Substitution test
4.4.1 Principle||t t||If alkali is added to the fresh milk, the bromophenol blue indicator will change color, and the amount of bromophenol blue can be judged by the color change. 1.4.2 Reagents
Liquid bromophenol blue (0,/)
4.4.3 Analysis steps
5. In the test tube, place the test material in the test tube and carefully add 5 drops of bromophenol blue-alcohol solution along the wall of the tube. Gently shake the test tube 3-3 times to make the test tube dry. Mutual contact, do not allow the liquids to mix. Then place the test tube vertically for 2 minutes. According to the change of the color of the annular layer, the result is confirmed: the fresh milk that has not been reduced for a period of time is self-control test: the result is determined by the limit of the annular layer color change, see 2.31 CB/T5C09.462003 Degree of bicarbonate in fresh milk (4.5 days, 5.1 Method A 4.5.1.1 Operation method Green color of the surface layer of the raw material Sodium content 5℃
fast color
cyan
hot
dark cyan
collect 5m7cm glass n2 refined seaweed in a dryer for 2h, weigh it, dry it with hydrogen, take 5.mL of it, dry it in a constant plate, steam it, quickly remove the water outside the blood, boil it at 95℃~105℃, collect it and dry it for 0.h, measure it, dry it for 1h, take 1 volume after cooling. The difference between the two masses is not more than 1.01%.
4. 5. 1. 2 Calculation of results
4.5.1.2.1 The total amount of green substance in the sample is calculated according to formula <3), m10
wherein:
content in the sample, is the dry mass of blood and sea salt, in grams per 100 grams (/g); positive sea salt, is the mass of blood and sea salt, in grams (9); 4.5.1.2.2 The drug content in the sample is calculated according to formula (4). -X
or
, the solid content of fat in the sample, unit is g/100g (10:X,
the total solid content in the test, unit is g/100g: -X
or
, the solid content of fat in the sample, unit is g/100g (10:X,
the total solid content in the test, unit is g/100g: -X
or
, the solid content of fat in the sample, unit is g/100g (10:X,
the total solid content in the test, unit is g/100g: -X
or
, the solid content of fat in the sample, unit is g/100g (10:X). The result shall be rounded to two significant digits.
4.5.73 The absolute difference between the independent results obtained under repeated conditions shall not exceed 5% of the arithmetic mean. 4.5.2 Method
to Formula (5) Formula (1), the total solid content of fat in the milk is calculated by the above formula, X: = 0.25X +1.2X: : 0. 14
Where:
X, the total salt content of a sample, expressed in grams per 100 grams (R/1006);
X, the fat content of a sample, expressed in grams per 100 grams (R/700g). If a 20/4000 g creamer is used, add 2 to the reading obtained and then calculate according to Formula 5). 4.6 Acid
4.6.1 Principle
Lactic acid in fresh milk increases due to the presence of microorganisms. The acid is boiled to a temperature sufficient to be 72
. It is used as an indicator. How many milliliters of sodium oxychloride standard solution (0.1c55mol/L) are required to neutralize 1U0nL of milk? 4.6.2 Reagents
4.6.2.1 Acid indicator: weigh 0.5g of lactic acid and a small amount of ethanol to degrade it to 5uUmI. 4.6.2.2 Sodium hydroxide standard titration solution c (N:H>=U.1ml/L) 4.6.3 Analytical steps
GB/T 5009.46—2003
Pipette the sample into a 15 μl conical flask. Place it in a cool water and alcohol-resistant indicator bottle, mix well, and titrate with sodium hydroxide standard (10 μl/l) until pink appears and the color does not stabilize within 0.5 min. Titrate with oxygen standard (3.100 μl/l). The number of drops required is multiplied by 10 and is taken as the acidity (μl). 4.6.4 Precision test The absolute difference between the results of two independent microassays obtained under heavy load shall not exceed μl. 4.7 For the first drop of AB66, perform the operation according to GB/T 009.19 and GB/T 5009.17. 4.9 Aflatoxin 3 (column chromatography purification-thin layer secondary determination method) 4. 9. 1 Principle
The sample is precipitated with acetone, and then demulsified sodium chloride solution is added. The yellow code is obtained by trifluoromethane. It can be adsorbed by the test gel; lipopeptides and impurities are removed by n-alkane and ethyl acetate, and then precipitated with acetone-methylene chloride solution, and thin layer determination is performed. The standard is used for comparison and quantification.
4.9.2 Reagents
4.9.2.1Silica gel H: generally used as a ten-test chromatography block filler, 80 days ~ 1CU day. Used for thin layer chromatography 211 days. 4.9.2.2F alcohol.
4.9.2.3 propanol.
trichloromethane,
4.9.2.5 hexane.
4.9.2.E acetaldehyde, no peroxide. Use the standard solution: prepare 1 ml of aflatoxin at 0.1°C with monochloroethane and store at 4 °C. Sodium methylcellulose (CMC) (4/L): take the supernatant after centrifugation at 10 °C for 10 min. 4.9.2.7 Sodium sulphate and sodium sulphate (15:L) anhydrous mineral acid
4.9.2.9 sulfuric acid (1:3)
4. Aflatoxin M, standard solution: prepare aflatoxin M at 0.1°C with monochloroethane and store at 4 °C.
Standard sodium methylcellulose (CMC) (4/L): take the supernatant after centrifugation at 10 °C for 10 min. 4.9.2. 11
4.9.5 Instruments
4.9.3.1365ura UV lamp
4.9.3.215X5m glass tube.
4.9.3.3 Column: inner length 25cm, inner width 6.5cm, inner height 3.=cm4.9.3.4 Micro-injection time retention: 5.50u.
4.9.3.5 Chromatography column: inner diameter ~, 5clm. Du Shang 2 m. With core and active cooling, 4.9.3.6 liquid gradual device; branch pipe concentrator bottle. 4.9.4 Analysis procedure
5.9.4.1 Sample extraction
Weigh 3U.00g of the sample, add 50ml of acetone in 25V InL of the auxiliary type, vibrate for 30min, filter with filter paper, wash with about 5r of propylene system and separate into 30L of methane, then add 20ml of chlorination liquid (4g/L) for 2min, separate into layers, one layer of liquid is passed through the filter paper with about 1g of water and acid, and then wash with anhydrous sulfuric acid in a small amount of chlorine to wash. Place the sample in a 6F/600 bottle and burn it in a water bath until the sample is completely dispersed. 4.9.4.2 Sample purification
4.9.4.2.1 Preparation of analytical column
4.9.4,2.1.1 Treatment of silica gel H
2) The silica gel H can be selected according to the number of test columns. First, stir the sample with methane, wash it with water, then draw it out, and then use trioxygen After the latent agent is completely evaporated, dry in a 113°C oven for 1 hour, collect and put into a bottle in a desiccator for future use. The time should not exceed 4.9.4.2.1.2 Column loading
Take the 2 H-treated gel. Use trichloroethane to transfer to a column with anhydrous acid at a height of about 0.5cm to .cm below the bottom to obtain silica gel After the inside is completely filled, add 2 L of sodium sulfate solution to cover it, and finally let monochloroethane flow into the upper layer without organic acid. 4.2.2 Note: Purification: Use 2 L of trifluoromethane once to transfer the sample to the chromatography column. After the liquid completely flows out of the inside, wash it twice with 3 (10) mL of n-hexane, wash it once with acetaldehyde, and discard the washing liquid. Use filter sheets, tear the inside and outside of the tube mouth clean, press 0ml propane-dioxymethane mixture (2:3) once for elution, collect in the ball-belt branch tube concentration tube, put in 55~7U water concentration car near the bottom, and then use a small amount of lanthanum to elute the bottle, and wave to the end. After cooling, cut into 1C. The three types of alkane decomposition mixture are evenly used for thin layer chromatography determination, and the standard recovery test is carried out at the same time. 2,9.4.3 Wing layer determination
E.9.4.3.1 Preparation of silica gel I plate
Weigh 1 aldehyde glue H and 1mL CMC concentrate (4g/), adjust to a uniform paste of 1:1m215m and evenly apply the entire plate on the glass plate. Place it in a horizontal position, put it under dust-free soft equipment, and then place it in a 1u5 material box with 1.55. Aspirate, cool, and store it in a container for storage.
4.9.4.3.2 Point board
In 15
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