Separation and detection method for adulteration of dairy raw materials

Abstract

The invention provides a separation and detection method for adulteration of dairy raw materials. The specific control operation steps are as follows: S1, accurate sampling treatment of dairy raw material samples; s2, performing optimization pretreatment operation on the dairy product raw material sample; s3, carrying out quality control treatment on the pre-treated sample; s4, sample substance chromatographic separation operation; according to the method, accurate sampling, sample pretreatment, quality control, chromatographic separation and chromatographic detection treatment are sequentially carried out on dairy raw materials through the five steps, samples are sampled in a multidirectional and differentiated mode in the sampling process of the samples, the representativeness of the samples is improved, and the detection accuracy of the samples is improved. In addition, in the sample pretreatment step, the sample is sequentially subjected to extraction, concentration, purification and dissolution treatment, so that the subsequent separation and detection effect of the sample is improved.

Description

Technical Field

[0001] The invention relates to the technical field of dairy product detection, in particular to a separation and detection method for adulteration of dairy product raw materials. Background Art

[0002] Dairy testing refers to the process of inspecting and monitoring the quality and safety of dairy products (including milk, yogurt, milk powder, etc.). Through dairy testing, the composition, nutritional value, microbiological quality, additives, residual substances and other aspects of dairy products can be evaluated to ensure that the products comply with relevant regulations and standards and the health needs of consumers. In recent years, some unscrupulous manufacturers have obtained illegal profits by adulterating dairy products, seriously endangering the legitimate interests and health of consumers. Therefore, dairy testing is particularly important. The adulteration of dairy products is detected through special testing methods. Laboratories usually use a series of chemical analysis and biotechnology methods to accurately detect and identify whether adulteration exists.

[0003] However, the existing detection methods for adulteration of dairy raw materials have the following problems: chromatography is often used to detect dairy raw materials, but in the actual detection process, dairy samples may not be properly processed during pretreatment, resulting in limited accuracy of dairy detection. In addition, the content of certain adulterants may be low, exceeding the detection range of chromatography, which may result in the inability to accurately detect trace amounts of adulterants. Therefore, it is necessary to design corresponding technical solutions to solve the existing technical problems. Summary of the invention

[0004] The purpose of the present invention is to provide a method for detecting dairy raw materials by chromatography, but in the actual detection process, the dairy samples may not be properly processed during pretreatment, resulting in limited accuracy of dairy detection. In addition, the content of certain adulterants may be low and exceed the detection range of chromatography, which may lead to the inability to accurately detect trace amounts of adulterants, which is a technical problem.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for separating and detecting adulteration of dairy raw materials, wherein the specific control operation steps are as follows:

[0006] S1: Precise sampling and processing of dairy raw material samples;

[0007] S2: Optimization of pretreatment operations for dairy raw material samples;

[0008] S3: pre-processing sample quality control processing;

[0009] S4: Chromatographic separation operation of sample substances;

[0010] S5: chromatographic detection and processing of test samples;

[0011] Through the above five steps, the dairy raw materials are sequentially subjected to precise sampling, sample pretreatment, quality control, chromatographic separation and chromatographic detection. In the process of sampling, the samples are sampled in a multi-faceted and differentiated manner to improve the representativeness of the samples. In addition, in the sample pretreatment step, the samples are sequentially extracted, concentrated, purified and dissolved, thereby improving the effect of subsequent separation and detection of the samples.

[0012] As a preferred embodiment of the present invention, S1: precise sampling and processing of dairy raw material samples, when sampling dairy raw materials, multi-directional sampling operations are performed on raw materials from different positions and different batches. When there are batch differences in the raw materials, samples from different batches are evenly mixed in a 1:1 manner to obtain a more representative sample. In addition, for solid samples, grinding or homogenization can be performed. During the sampling process, the obtained samples are introduced into a mixing container for sufficient stirring and mixing.

[0013] As a preferred embodiment of the present invention, S2: Optimize the pretreatment operation of the dairy raw material sample, which is divided into extraction, concentration, purification and dissolution according to the operation steps, wherein a, extraction: introduce the sample obtained in S1 into a container and adopt a liquid-liquid extraction method, use an organic extractant to introduce it into the container and stir it thoroughly, the stirring temperature is controlled at 20°C-30°C, the stirring speed is controlled at 800r / min-1200r / min, and the stirring time is controlled at 1h-1.5h; b, concentration: introduce the fully mixed raw material mixture into an evaporation container by evaporation concentration, the evaporation temperature is controlled at 100°C and the mixture is kept in the evaporation process. The mixture is continuously stirred to evaporate the internal liquid and grind the mixture into fine particles; c. Purification: The concentrated extract is purified by membrane separation. First, the mixture is introduced into a nanofiltration membrane with a pore size of 10nm-30nm for vibration separation, mainly for separating impurities in the mixture. Then, the filtered mixture is introduced into an ultrafiltration membrane with a pore size of 1nm-5nm for vibration separation, and the protein and colloidal components in the dairy raw materials are separated; d. Dissolution: The treated dairy raw materials are introduced into pure water for sufficient stirring so that there is no sediment at the bottom of the mixing container.

[0014] As a preferred embodiment of the present invention, S3: pre-processing the sample for quality control, preparing the dissolved sample into 10 test samples, and controlling the weight of the sample to 100 g.

[0015] As a preferred embodiment of the present invention, S4: chromatographic separation operation of sample substances, a gas chromatograph is used to perform chromatographic separation on the test sample, wherein the flow rate is controlled within the range of 1 mL / min-2 mL / min, the temperature is generally controlled between 40°C and 250°C, and the sample is injected into the gas chromatograph through the inlet and separated and processed through the chromatographic column.

[0016] As a preferred embodiment of the present invention, S5: chromatographic detection processing of the detection sample, data processing and analysis are performed according to the data output by the instrument, and the components in the sample are compared with the characteristics of the standard, so that the adulterated substances in the dairy raw materials can be accurately detected.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention designs a method specifically for detecting adulteration of dairy products. When it is necessary to detect adulteration of dairy products, accurate sampling, sample pretreatment, quality control, chromatographic separation and chromatographic detection processing are sequentially performed on the samples. In the process of sampling the samples, a multi-directional and differentiated manner is adopted to sample the samples to improve the representativeness of the samples. In addition, in the sample pretreatment step, the samples are sequentially extracted, concentrated, purified and dissolved, thereby improving the effect of subsequent separation and detection of the samples. DETAILED DESCRIPTION

[0019] Embodiment 1:

[0020] A separation and detection method for adulteration of dairy raw materials, the specific control operation steps are as follows:

[0021] S1: Precise sampling and processing of dairy raw material samples;

[0022] S2: Optimization of pretreatment operations for dairy raw material samples;

[0023] S3: pre-processing sample quality control processing;

[0024] S4: Chromatographic separation operation of sample substances;

[0025] S5: chromatographic detection and processing of test samples;

[0026] Through the above five steps, the dairy raw materials are sequentially subjected to precise sampling, sample pretreatment, quality control, chromatographic separation and chromatographic detection. In the process of sampling, the samples are sampled in a multi-faceted and differentiated manner to improve the representativeness of the samples. In addition, in the sample pretreatment step, the samples are sequentially extracted, concentrated, purified and dissolved, thereby improving the effect of subsequent separation and detection of the samples.

[0027] S1: Precise sampling and processing of dairy raw material samples. When sampling dairy raw materials, multi-directional sampling operations are performed on raw materials from different locations and batches. When there are batch differences in the raw materials, samples from different batches are evenly mixed in a 1:1 manner to obtain more representative samples. In addition, for solid samples, grinding or homogenization can be performed. During the sampling process, the obtained samples are introduced into a mixing container for sufficient stirring and mixing.

[0028] S2: Optimize the pretreatment operation of dairy raw material samples, which are divided into extraction, concentration, purification and dissolution according to the operation steps, among which, a. Extraction: introduce the sample obtained in S1 into a container and use liquid-liquid extraction method, use organic extractant to introduce it into the container and stir it thoroughly, the stirring temperature is controlled at 20℃-30℃, the stirring speed is controlled at 800r / min-1200r / min, and the stirring time is controlled at 1h-1.5h; b. Concentration: Use evaporation concentration method to introduce the fully mixed raw material mixture into the evaporation container, the evaporation temperature is controlled at 100℃ and the mixture is kept stirred continuously during the evaporation process Treatment: evaporate the internal liquid and grind the mixture into fine powder; c. Purification: purify the concentrated extract by membrane separation. First, introduce the mixture into a nanofiltration membrane with a pore size of 10nm-30nm for vibration separation, mainly for separating impurities in the mixture. Then, introduce the filtered mixture into an ultrafiltration membrane with a pore size of 1nm-5nm for vibration separation, and separate the protein and colloidal components in the dairy raw materials; d. Dissolution: introduce the treated dairy raw materials into pure water for sufficient stirring so that there is no sediment at the bottom of the mixing container.

[0029] S3: Pre-treatment sample quality control treatment, the dissolved sample is made into 10 test samples, and the weight of the sample is controlled at 100g.

[0030] S4: Chromatographic separation operation of sample substances. A gas chromatograph is used to perform chromatographic separation on the test samples. The flow rate is controlled within the range of 1 mL / min-2 mL / min, and the temperature is generally controlled between 40°C and 250°C. The samples are injected into the gas chromatograph through the injection port and separated by the chromatographic column.

[0031] S5: Detection sample chromatographic detection processing, based on the data output by the instrument, data processing and analysis are carried out, and the components in the sample are compared with the characteristics of the standard, so that the adulterated substances in the dairy raw materials can be accurately detected.

[0032] When the present invention needs to detect the problem of adulteration of dairy products, the sample is sequentially subjected to precise sampling, sample pretreatment, quality control, chromatographic separation and chromatographic detection processing, wherein in the process of sampling the sample, the sample is sampled in a multi-directional and differentiated manner to improve the representativeness of the sample, and in addition, in the sample pretreatment step, the sample is sequentially extracted, concentrated, purified and dissolved, thereby improving the effect of subsequent separation and detection of the sample.

[0033] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for separating and detecting adulteration of dairy raw materials, characterized in that: The specific control operation steps are as follows: S1: Precise sampling and processing of dairy raw material samples; S2: Optimization of pretreatment operations for dairy raw material samples; S3: pre-processing sample quality control processing; S4: Chromatographic separation operation of sample substances; S5: chromatographic detection and processing of test samples; Through the above five steps, the dairy raw materials are sequentially subjected to precise sampling, sample pretreatment, quality control, chromatographic separation and chromatographic detection. In the process of sampling, the samples are sampled in a multi-faceted and differentiated manner to improve the representativeness of the samples. In addition, in the sample pretreatment step, the samples are sequentially extracted, concentrated, purified and dissolved, thereby improving the effect of subsequent separation and detection of the samples.

2. The method for separating and detecting adulteration of dairy raw materials according to claim 1, characterized in that: S1: Precise sampling and processing of dairy raw material samples. When sampling dairy raw materials, multi-directional sampling operations are performed on raw materials from different locations and batches. When there are batch differences in the raw materials, samples from different batches are evenly mixed in a 1:1 manner to obtain more representative samples. In addition, for solid samples, grinding or homogenization can be performed. During the sampling process, the obtained samples are introduced into a mixing container for sufficient stirring and mixing.

3. The method for separating and detecting adulteration of dairy raw materials according to claim 1, characterized in that: S2: Optimize the pretreatment operation of dairy raw material samples, which are divided into extraction, concentration, purification and dissolution according to the operation steps, among which, a. Extraction: introduce the sample obtained in S1 into a container and use liquid-liquid extraction method, use organic extractant to introduce it into the container and stir it thoroughly, the stirring temperature is controlled at 20℃-30℃, the stirring speed is controlled at 800r / min-1200r / min, and the stirring time is controlled at 1h-1.5h; b. Concentration: Use evaporation concentration method to introduce the fully mixed raw material mixture into the evaporation container, the evaporation temperature is controlled at 100℃ and the mixture is kept stirred continuously during the evaporation process Treatment: evaporate the internal liquid and grind the mixture into fine powder; c. Purification: purify the concentrated extract by membrane separation. First, introduce the mixture into a nanofiltration membrane with a pore size of 10nm-30nm for vibration separation, mainly for separating impurities in the mixture. Then, introduce the filtered mixture into an ultrafiltration membrane with a pore size of 1nm-5nm for vibration separation, and separate the protein and colloidal components in the dairy raw materials; d. Dissolution: introduce the treated dairy raw materials into pure water for sufficient stirring so that there is no sediment at the bottom of the mixing container.

4. The method for separating and detecting adulteration of dairy raw materials according to claim 1, characterized in that: S3: Pre-treatment sample quality control treatment, the dissolved sample is made into 10 test samples, and the weight of the sample is controlled at 100g.

5. The method for separating and detecting adulteration of dairy raw materials according to claim 1, characterized in that: S4: Chromatographic separation operation of sample substances. A gas chromatograph is used to perform chromatographic separation on the test samples. The flow rate is controlled within the range of 1 mL / min-2 mL / min, and the temperature is generally controlled between 40°C and 250°C. The samples are injected into the gas chromatograph through the injection port and separated by the chromatographic column.

6. The method for separating and detecting adulteration of dairy raw materials according to claim 1, characterized in that: S5: Detection sample chromatographic detection processing, based on the data output by the instrument, data processing and analysis are carried out, and the components in the sample are compared with the characteristics of the standard, so that the adulterated substances in the dairy raw materials can be accurately detected.