QB/T 5395-2019Concentrated milk (English PDF)

4.6 Limits of microorganisms

Products using heat treatment process shall conform to the provisions of Table 3 in GB

19645. Products using cold treatment processes such as ultrafiltration or reverse osmosis, after being diluted in equal proportions according to concentration multiples, shall conform to the provisions of the microorganism limits specified in GB19301.

5.1 Sensory requirements

Liquid (semi-solid) concentrated milk: Take an appropriate amount of sample and place it in a 50mL beaker. Observe its color and structural state under natural light. Smell its odor. Rinse with warm water and taste it.

Solid concentrated milk: Take an appropriate amount of sample; place it in a clean, dry white porcelain dish; observe its color and appearance under natural light. Smell its odor. Rinse with warm water and taste it.

5.2 Protein

Test according to the method specified in GB 5009.5.

5.3 Fat

Test according to the method specified in GB 5009.6.

5.4 Non-fat milk solid

Test according to the method specified in GB 5413.39.

5.5 pH

5.5.1 Sample preparation

It shall be carried out according to the method of 5.5.2 ~ 5.5.4; and other test procedures shall be carried out according to the method specified in GB 5009.237.

5.5.2 Sampling

The samples received by the laboratory shall be representative and not damaged or changed during transportation and storage. Take representative samples.

5.5.3 Homogenized samples

For liquid or semi-solid samples stored at room temperature, use mechanical equipment (high-speed rotating cutter or food mixer with crushing function, etc.) to homogenize the sample. Take care to avoid the sample temperature exceeding 25°C.

For samples that are solid due to freezing, take (200 ± 5) g (accurate to 0.01g) of samples to be homogenized and thawed in the above mechanical equipment. Note that the entire homogenization and thawing process does not exceed 0.5h; put the sample in sealed containers to prevent deterioration and composition changes.

The sample shall be analyzed as soon as possible. For samples stored at room temperature, no more than 24h after homogenization; for samples stored frozen, no more than 1h after thawing and homogenization.

5.5.4 Heterogeneous samples

Select a representative pH test point among the samples, and continuous to operate according to the heterogeneous sample in GB 5009.237.

6.1 Group batch

The quality management department of the production enterprise determines the batch of products in accordance with the corresponding rules.

6.2 Random-sampling

Products are randomly sampled in batches.

For pre-packaged products, take 5 pieces of packaging samples. For large package products over 10kg, 500 mL (g) of products may be sub-packed from the 5 packaged samples that are respectively taken as the samples; and the total sampling amounts of samples shall be no less than 2500 mL (g).

For milk storage tank products, first start the mechanical stirring device to stir the milk storage tank for at least 5 minutes before sampling. For milk storage tanks that do not have mechanical stirring equipment, use a manual stirrer to probe into the bottom of the tank before sampling, and stir from bottom to top evenly. After the sample is thoroughly mixed, use a sampler such as a liquid milk bucket to sample from three points at the surface, middle and bottom. Mix the samples collected at three points into the container and mix them thoroughly; then use a sampling bottle to divide into three parts. The total amount of each sample is no less than 3 times the test detection amount. The sampler shall comply with the relevant standards.

6.3 Exit-factory inspection

Before leaving the factory, the quality inspection department of the production enterprise shall inspect the products batch by batch according to the provisions of this

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