GB 4789.18-2024 National food safety standard
Food microbiological examination - Sampling and sample processing of milk and dairy products
1 Scope
This standard specifies the sampling and sample processing methods of milk and dairy products.
This standard is applicable to the sampling and sample processing of milk and dairy products.
2 Equipment and materials
2.1 Sampling tools
The sampling tools shall be made of stainless steel or other materials with appropriate strength, and they shall have smooth surfaces, and rounded corners, but not joints. The sampling tools shall be cleaned and sterilized and kept dry before use. Sampling tools include stirring appliances, sampling scoops and spoons, cutting wires, scissors, cutting tools (knives or spatulas), sampling drills, etc.
2.2 Sample containers
The material (such as glass, stainless steel, and plastic) and structure of the sample containers shall be able to fully make the samples the original state. The containers and their lids shall be clean, sterile, and dry. The sample containers shall have sufficient volume to allow the samples to be thoroughly mixed prior to inspection. The sample containers also include sampling bags, sampling tubes, sampling bottles, and the like.
2.3 Other supplies
They may include the alcohol lamp, thermometer, aluminum foil, sealing film, marker, and sampling registration form.
3 Sampling
3.1 Sampling principles and plans
The sampling principles and plans shall be implemented in accordance with the requirements of GB 4789.1.
The number (n) of the specimens to be sampled shall meet the requirements of relevant food safety standards. The sampling volume for each sample shall not be less than the volume of the sample for 5 × inspection units, or shall be determined according to the inspection purpose. The requirements for the sampling of food samples are specified as follows:
3.2 Fresh milk
3.2.1 The sample shall be mixed as thoroughly as possible, and sampling shall be done immediately after mixing. The sterile sampling tool shall be used to collect samples from the same batch (specifically referring to individual milk storage tanks or milk tankers).
3.2.2 For milk storage devices with partitioned areas, a proportionate amount of well-mixed representative samples shall be collected from each partitioned area based on the different quantities of milk stored in each area. Sampling after mixing is not allowed.
3.3 Liquid dairy products (pasteurized milk, high-temperature sterilized milk, modified milk, etc.)
3.3.1 Individually packaged liquid dairy products of less than or equal to 1,000g (mL): individually packaged liquid dairy products from the same batch shall be sampled.
3.3.2 Individually packaged liquid dairy products of more than 1,000g (mL): individually packaged liquid dairy products from the same batch shall be sampled; or sampling shall be conducted after shaking and mixing evenly.
3.4 Semi-solid dairy products
3.4.1 Concentrated dairy products, fermented milk, and flavored fermented milk
3.4.1.1 Individually packaged products of less than or equal to 1,000g (mL): individually packaged products from the same batch shall be sampled.
3.4.1.2 Individually packaged products of more than 1,000g (mL): the sample shall be shaken or stirred with an agitator before sampling to achieve uniformity, and then sampled.
If the sample cannot be mixed uniformly, representative samples shall be taken from different parts of the sample container.
3.4.2 Single cream, cream, and anhydrous cream
3.4.2.1 Individually packaged products of less than or equal to 1,000g (mL): individually packaged products from the same batch shall be sampled.
3.4.2.2 Individually packaged products of more than 1,000g (mL): the sample shall be shaken or stirred with an agitator before sampling to achieve uniformity, and then sampled. For solid cream and its products, a sterile spatula shall be used to remove the surface product, with a thickness of not less than 5 mm. The clean and dry sampling drill shall be inserted downwards along the cutting direction of the packaging container, at a constant speed, into the bottom. When the sampling drill reaches the bottom of the container, the sampling drill shall be rotated 180° and then withdrawn, and the collected sample shall be transferred into the sample container.
3.5 Solid dairy products (cheese, processed cheese, cheese products, milk powder, modified milk powder, whey powder and whey protein powder, casein and caseinates, etc.)
3.5.1 Individually packaged products of less than or equal to 1,000g: individually packaged products from the same batch shall be sampled.
3.5.2 For individually packaged cheese, processed cheese, and cheese products weighing more than 1000g, the following methods of sampling may be used based on the shape and type of the product: (1) At a distance of not less than 10 cm from the edge, insert the sampler diagonally towards the center of the product to a flat surface, and take one or more samples; or (2) insert the sampler perpendicularly into one side and through the center of the product to the opposite side for sampling; or (3) insert the sampler horizontally between two planes into the vertical surface of the product, directing it towards the center for sampling; or (4) if the product is packaged in barrels, boxes, or other large containers, or if the product is formed into compacted large blocks, insert the sampler diagonally from the top of the container to the bottom for sampling.
3.5.3 For individually packaged products such as milk powder, modified milk powder, whey powder and whey protein powder, casein and caseinates, etc., weighing more than 1,000g, the sterile and dry sampling drill shall be inserted at a constant speed along the cutting direction of the packaging container with the face down. When the sampling drill reaches the bottom of the container, the sampling drill shall be withdrawn and the collected sample shall be transferred into the sample container.
3.6 Sample storage and transportation
The requirements of GB 4789.1 shall apply.
4 Preparation of samples
4.1 Opening of packages
The sterile sampling container in which the sample is packaged or placed shall be opened aseptically. Products packaged in plastic or paper boxes (bags): sterilize the box lid or bag mouth with 75% alcohol cotton ball, and cut it open with aseptic scissors; products packaged in bottles (barrels): sterilize the package with 75% alcohol cotton ball or flame, remove the bottle (barrel) cap aseptically, and sterilize the bottle (barrel) mouth by flame.
Contents
Foreword i
1 Scope
2 Equipment and materials
3 Sampling
4 Preparation of samples
5 Inspection
