This standard specifies the basic requirements and test methods for milk and dairy products. This standard applies to the test of fresh milk and its products (the total bacterial count test is not applicable to yogurt). GB/T 4789.18-2003 Food Hygiene Microbiological Test Milk and Dairy Products Test GB/T4789.18-2003 Standard Download Decompression Password: www.bzxz.net

ICS07.100.30
National Standard of the People's Republic of China
GB/T4789.18—2003
Replaces GB/T4789.18—1994
Microbiological examination of food hygiene—Examination of milk and milkproductsPromulgated on August 11, 2003
Ministry of Health of the People's Republic of China
Standardization Administration of the People's Republic of China
Implementation on January 1, 2004
GB/T4789.18—2003
This standard revise GB/T4789.18—1994 "Microbiological examination of food hygiene—Examination of milk and milk products". Compared with GB/T4789.18-1994, this standard has the following major revisions: 1. The dairy products in this standard are reclassified according to the newly revised food hygiene standards. The format and text of the standard text are revised in accordance with GB/T1.1-2000. The "equipment and materials" in the original standard are revised and standardized. The "reference standards" are revised and standardized.
The content of the operating procedures has been revised.
From the date of implementation of this standard, GB/T4789.18-1994 will be abolished at the same time. This standard is proposed and managed by the Ministry of Health of the People's Republic of China. The drafting unit of this standard: Nutrition and Food Safety Institute of China Center for Disease Control and Prevention. The main drafters of this standard: Ji Rong, Fu Ping, Yao Jinghui. This standard was first issued in 1984, revised for the first time in 1994, and this is the second revision. 144
1 Scope
Microbiological examination of food hygiene
Inspection of milk and milk products
This standard specifies the basic requirements and inspection methods for the inspection of milk and milk products. This standard applies to fresh milk and its products (the total bacterial count inspection is not applicable to the inspection of yogurt). 2 Normative references
GB/T4789.18—2003
The clauses in the following documents become the clauses of this standard through reference in this standard. For any dated referenced document, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, it is encouraged to The parties who reach an agreement based on this standard shall study whether the latest versions of these documents can be used. For any undated referenced documents, the latest versions shall apply to this standard. GB/T4789.1 General principles for food hygiene microbiological examination GB/T4789.2 Determination of total colony count for food hygiene microbiological examination GB/T4789.3 Determination of coliform group for food hygiene microbiological examination
GB/T4789.4 Salmonella test for food hygiene microbiological examination GB/T4789.5 Shigella test for food hygiene microbiological examination GB/T4789.10 Golden Saccharomyces cerevisiae test for food hygiene microbiological examination Staphylococcus test
GB/T4789.15 Microbiological test for food hygiene Count of mold and yeast
GB/T16347 Microbiological test for food hygiene Test for lactic acid bacteria in lactic acid beverages 3 Equipment and materials
Supplies for on-site sampling
3.1.1 Sampling box.
3.1.2 Stirring rod.
3.1.3 Spoon.
3.1.4 Sterilized wide-mouth bottle with stopper.
3.1.5 Sterilized plastic bag.
3.1.6 Thermometer.
3.1.7 75% alcohol cotton ball. || tt||3.1.8 Crayons and paper for numbering.
3.2 Laboratory test supplies
See GB/T4789.2, GB/T4789.3, GB/T4789.4, GB/T4789.5, GB/T4789.10, GB/T4789.15, GB/T16347.
4 Culture media and reagents
See GB/T4789.2, GB/T4789.3, GB/T4789.4, GB/T4789.5, GB/T4789.10, GB/T4789.15, GB/T 16347.
GB/T4789.18—2003bZxz.net
5 Operation steps
5.1 Sampling and inspection
5.1.1 Fresh milk in large packages: Use a sterilized pipette to take samples. Pay attention to representativeness when sampling. The number of samples shall comply with GB/T4789.1. Put the samples in a sterilized container and send them for inspection in time. In the case of high temperature or long distance, the samples shall be refrigerated and no preservatives shall be used. 5.1.2 Dairy products in fixed packages: Take the whole package. Pay attention to the integrity of the package when sampling. The sample quantity of each package of milk and dairy products in various fixed packages shall comply with the requirements of GB/T4789.1.
5.2 Sample Handling
5.2.1 Fresh milk and yogurt: For plastic or paper boxes (bags), use 75% alcohol cotton balls to disinfect the box cover or bag mouth; for glass bottled yogurt, remove the paper cover of the bottle mouth with aseptic procedures, sterilize the bottle mouth with flame, draw 25mL of sample with aseptic procedures, put it into a conical flask containing 225mL of sterilized physiological saline, and shake it evenly (if there is water on the surface of yogurt, it should be removed first). 5.2.2 Condensed milk: Wash the surface of the bottle or can with warm water, then use a lit alcohol cotton ball to disinfect the upper part of the bottle or can, then use a sterilized can opener to open the can or bottle, weigh 25g (mL) of sample with aseptic procedures, put it into a conical flask containing 225mL of sterilized physiological saline, and shake it evenly.
5.2.3 Cream and butter: Open the package with aseptic procedures, take an appropriate amount of sample and place it in a sterile conical flask, heat it in a 45℃ water bath or incubator, take out the flask immediately after it dissolves, use a sterile pipette to draw 25mL of the sample, and place it in another flask containing 225mL of sterile physiological saline or sterile cream or butter diluent 1 (the bottled diluent should be pre-placed in a 45℃ water bath to keep warm, and the same diluent should be used for 10-fold incremental dilution). Shake evenly. The time from the melting of the sample to the completion of inoculation should not exceed 30 minutes. 5.2.4 Milk powder: The method of sampling canned milk powder is the same as that of condensed milk. For bagged milk powder, rub the bag mouth with cotton balls soaked in 75% alcohol to disinfect it. Open the bag and take samples aseptically. Weigh 25g of the sample and put it into a sterilized conical bottle with an appropriate amount of glass beads. Slowly add 225mL of warm sterilized saline (first use a small amount of saline to make the milk powder into a paste, then add it all to prevent the milk powder from agglomerating). Shake to fully dissolve and mix. 5.2.5 For cheese: First use a sterilized knife to scrape off part of the surface wax, then use a lit alcohol cotton ball to disinfect the surface, then use a sterilized knife to cut the cheese, and then use a sterile procedure to cut a small amount of surface and deep sample, weigh 25g and put it into a homogenizer containing 225mL of sterilized saline to break it. 6 Test methods
- Determination of total colony count: in accordance with GB/T4789.2; Determination of coliform group: in accordance with GB/T4789.3; Salmonella test: in accordance with GB/T4789.4; Shigella test: in accordance with GB/T4789.5; Staphylococcus aureus test: in accordance with GB/T4789.10: - Mold and yeast count: in accordance with GB/T4789.15; Lactic acid bacteria test: in accordance with GB/T16347. 1) Cream diluent: Ringer's solution (preparation: sodium chloride 9g, potassium chloride 0.12g, calcium chloride 0.24g, sodium bicarbonate 0.2g, distilled water 1000mL) 250mL, distilled water 750mL, agar 1g, heat to dissolve, dispense 225mL per bottle, sterilize at 121℃ for 15min. 146
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