Method for evaluating risk of insoluble particles in wine body

Abstract

The invention mainly relates to the technical field of food safety risk assessment, and provides a method for evaluating the risk of insoluble particles in liquor, which is used for carrying out risk assessment on the insoluble particles in liquor. The method mainly comprises the steps that S1, an infrared spectrum image of a wine body is collected, the category of insoluble particles in the wine body is recognized, and whether the particles in the wine body meet the food safety requirement or not is judged according to the category recognition result of the insoluble particles in the wine body; s2, identifying the number and the particle size of insoluble particles in the wine body, and judging whether the wine body meets the wine quality and appearance requirements or not according to the number and the size of the insoluble particles in the wine body; and S3, making corresponding measures according to the food safety judgment result of the wine body and the wine quality appearance requirement judgment result to reduce the risk of insoluble particles in the wine body.

Description

Technical Field

[0001] The invention mainly relates to the technical field of food safety risk assessment, and in particular to a method for evaluating the risk of insoluble particles in wine. Background Art

[0002] According to the national standard for the appearance of distilled liquor, distilled liquor must meet the requirements of "colorless, slightly yellow, clear and transparent, without suspended matter, precipitation, and impurities (when the temperature of the liquor is below 10°C, white flocculent precipitation or loss of gloss is allowed, and it should gradually return to normal when it is above 10°C)". After checking, it was found that this is the unified regulation for the appearance of the five major world distilled liquors, including Chinese liquor (including twelve flavors), brandy, rum, whiskey, and vodka, indicating that there must be no impurities visible to the naked eye in distilled liquor.

[0003] According to literature reports, the minimum size that most people can see at a visual distance of 25cm is 100μm, but particles larger than 100μm have been found in the wine, which no longer meets the national standards for liquor. Due to the complexity of the winemaking process, such as the brewing process of Wuliangye, more than 100 processes are required from the entry of raw materials to packaging and shipment. For the quality of liquor, each process is a risk point. However, distilled liquor has a special flavor, and excessive processing methods cannot be used to achieve a colorless and transparent appearance. For example, after filtering through a reverse osmosis membrane, the flavor substances in the wine body are severely lost, thereby losing the unique flavor of the wine.

[0004] However, there is currently no accurate analysis and research on the specific impact of insoluble particles in liquor on the quality of the liquor. Summary of the invention

[0005] Technical Problems to be Solved by the Invention

[0006] This paper provides a method for evaluating the risk of insoluble particles in liquor, aiming to establish a process and standard for assessing the food safety risk and appearance risk of insoluble particles in liquor.

[0007] The technical solution adopted by the present invention to solve the above problems

[0008] A method for evaluating the risk of insoluble particles in wine comprising:

[0009] Step S1: collecting infrared spectrum images of the wine body, identifying the types of insoluble particles in the wine body, and judging whether the particles in the wine body meet the food safety requirements according to the identification results of the types of insoluble particles in the wine body;

[0010] Step S2: Identify the number and particle size of insoluble particles in the wine, and determine whether the wine meets the wine quality appearance requirements based on the number and size of the insoluble particles in the wine;

[0011] Step S3: reducing the risk of insoluble particles in the wine body according to the food safety determination result of the wine body and the determination result of the wine quality appearance requirement.

[0012] Furthermore, the specific method of collecting the infrared spectrum image of the wine body and identifying the type of insoluble particles in the wine body in step S1 is:

[0013] Step a: Evaluate the production nodes that may introduce visible foreign matter during the winemaking process and identify the target objects of visible foreign matter that may be introduced at each production node;

[0014] Step b: preparing the target objects identified in step S1 into samples to be tested respectively;

[0015] Step c: collecting infrared spectrum images of each sample to be tested;

[0016] Step d: establishing an infrared spectrum library of insoluble particles in liquor according to the infrared spectrum images of each sample to be tested;

[0017] Step e: Match the infrared spectrum image of the insoluble particle detection sample in the established insoluble particle infrared spectrum library, and identify the type of the insoluble particles according to the matching result.

[0018] Furthermore, in step S2, the number and particle size of insoluble particles in the wine are identified based on the light inspection method to determine whether the insoluble particles in the wine meet the appearance requirements of wine quality.

[0019] Further, step b specifically includes:

[0020] Step Sb1: using a sand core filter device to filter the liquor containing insoluble particles through a filter membrane under negative pressure to enrich the insoluble particles;

[0021] Step Sb2: Place the filter membrane in a culture dish to air-dry and then place it on a slide, and place the entire slide directly on the stage of an infrared microscope, adjust the instrument aperture illumination, and focus and stitch the image of the entire filter membrane;

[0022] Step Sb3: Add liquid nitrogen to the microscopic infrared spectrometer, use the wizard function in the Omnipicta software to mark the particles of the entire filter membrane image spliced ​​in step Sb2, and collect spectra of the marked particles one by one.

[0023] Furthermore, in step Sb1, the wine sample filtration volume is 5 to 20 ml, the filter membrane is a silicon membrane, the pore size of the silicon membrane is 1 μm, and the size is 1 cm×1 cm; the negative pressure of the filtration makes the filtration speed no higher than 5 ml / min.

[0024] Furthermore, in step Sb2, the magnification of the infrared microscope is 150 times, and the conditions for clear focus are: upper illumination is 100, aperture illumination is 0, and lower illumination is 50; the width and height of the aperture are both 150um, and the angle is 0°.

[0025] Furthermore, the amount of liquid nitrogen added in step Sb3 is about 500 ml, the acquisition mode of the microscopic infrared device is: transmission mode, the detector is: MCT detector, and the spectral range of the detector is 4000 cm -1 -675cm -1 The number of scans for collecting the single-beam spectrum of each particle is 16, and the single acquisition time is 3 seconds.

[0026] Furthermore, step S1 of judging whether the particles in the wine meet the food safety requirements according to the results of the category identification of insoluble particles in the wine specifically includes: if the categories of the insoluble particles in the wine include one or more of protein, starch, and higher fatty acid esters, the wine meets the food safety requirements; if the categories of the insoluble particles in the wine are identified as microplastics, metal oxides, silk cloth, and velvet cloth, the wine meets the food safety requirements.

[0027] Furthermore, step S2 of identifying the number and particle size of insoluble particles in the wine body, and judging whether the wine body meets the wine quality appearance requirements based on the number and size of the insoluble particles in the wine body specifically includes: if there are insoluble particles with a particle size greater than 100 μm in the wine body, the wine body does not meet the wine quality appearance requirements; if there are no insoluble particles with a particle size greater than 100 μm in the wine body, judging whether the wine body meets the wine quality appearance requirements is combined with the number of insoluble particles.

[0028] Beneficial effects of the present invention

[0029] The method for evaluating the risk of insoluble particles in wine described in the present invention identifies the type of insoluble particles in the wine by collecting infrared spectrum images of the wine, and simultaneously identifies the particle size of the insoluble particles in the wine, determines the risk of insoluble particles in the wine according to the type and particle size of the insoluble particles in the wine, and then executes corresponding measures according to the risk determination result to reduce the risk of insoluble particles in the wine, and can better perform food safety risk assessment on insoluble particles in the wine. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is the distribution diagram of particles (larger than 50 μm) under microscopic imaging after filtering a normal wine sample;

[0031] Figure 2 This is the distribution diagram of particles (larger than 50 μm) after filtering abnormal wine samples under microscopic imaging;

[0032] Figure 3 This is a microscopic image of a 100-fold dilution of a 5ml / 50μm standard particle size material;

[0033] Figure 4 This is a microscopic image of a 5ml / 50μm standard particle size material diluted 200 times;

[0034] Figure 5 This is a microscopic image of a 500-fold dilution of a 5 ml / 50 μm standard particle size material. DETAILED DESCRIPTION

[0035] A method for evaluating the risk of insoluble particles in wine according to the present invention comprises the following steps:

[0036] Step S1: collecting infrared spectrum images of the wine body, identifying the types of insoluble particles in the wine body, and judging whether the particles in the wine body are substances permitted in food safety according to the results of the identification of the types of insoluble particles in the wine body;

[0037] Step S2: Identify the particle size of the insoluble particles in the wine, and determine whether the wine meets the wine quality appearance requirements according to the size of the insoluble particles in the wine;

[0038] Step S3: reducing the risk of insoluble particles in the wine according to the risk assessment results.

[0039] Preferably, when classifying insoluble particles in wine, the production nodes that may introduce visible foreign matter in the winemaking process are evaluated, and the target objects that introduce visible foreign matter in each production node are identified, and the target objects are prepared as samples to be tested respectively; infrared spectrum images of each sample to be tested are collected, and an infrared spectrum library of visible foreign matter in liquor is established based on the infrared spectrum images of each sample to be tested, and the infrared spectrum images of insoluble particles are matched with their sources and types in the winemaking production process, and the spectrum images of the samples to be tested are matched in the established infrared spectrum library to identify the types and sources of insoluble particles. At the same time, the particle size of insoluble particles is identified according to the light inspection method. The risk of insoluble particles in wine is assessed based on their source, type and particle size. The specific criteria are shown in Table 1. Targeted prevention or improvement measures are formulated based on the risk assessment results. If the insoluble particles are found to be foreign particles such as higher fatty acid esters, proteins and starches, the food safety risk is relatively small and meets the food safety requirements. In order to meet the appearance quality requirements in the national standard, the content of higher fatty acid esters and proteins in the wine can be appropriately reduced based on the evaluation results of the light inspection method, or enterprise standards can be formulated based on the research results. If the insoluble particles are found to come from silk cloth or flannel, it is necessary to consider whether the material of the equipment from the corresponding source needs to be replaced or whether the terminal filter element needs to be replaced, and formulate the corresponding usage cycle, etc.

[0040] Table 1 Risk assessment criteria for insoluble particles

[0041]

[0042] Note: "Y" is clearly visible; "N" is not clearly visible

[0043] Example 1

[0044] (1) Take 10 ml of each of the wine samples that pass the lamp inspection and the wine samples that fail the lamp inspection, and filter them through a silicon membrane under negative pressure. Place the filtered silicon membrane in a clean culture dish and let it dry naturally. The pore size of the silicon membrane is 1 μm and the size is 1 cm × 1 cm. The negative pressure of the filtration should ensure that the filtration speed is no higher than 5 ml / min.

[0045] (2) Place the naturally dried silicon film on an appropriate slide and transfer it to the stage. Use the joystick configured on the Nicoleti N10 Fourier transform microscope infrared spectrometer to move the sample on the stage and position it in the observation area of ​​the objective lens. Adjust the aperture illumination, focus and stitch the entire silicon film image. Adjust the illumination parameters to upper illumination: 100, aperture illumination: 0, lower illumination: 50. The width and height of the aperture are both 150 μm, and the angle is 0°.

[0046] (3) Add 500 ml of liquid nitrogen to the microscopic infrared spectrometer, wait for the instrument to stabilize, stitch the images, classify and count the particle sizes on the images, and perform statistical analysis on foreign matter larger than 50 μm to obtain the particle size data results. The original spectrum is analyzed and compared with the spectrum library. Combined with the wine production process, the particle distribution images of the wine bodies that pass the light inspection and those that fail the light inspection are shown as follows: Figure 1 and Figure 2 The particle size results are shown in Tables 2 and 3.

[0047] Table 2 Size of insoluble particles in wine samples that passed the lamp test

[0048]

[0049] Table 3 Size of insoluble particles in wine samples that failed the lamp test

[0050]

[0051] (4) According to the judgment results of professional light inspection personnel on the wine samples, combined with the analysis of the corresponding wine samples by instruments and equipment, it was concluded that the particle size and number of foreign particles in normal wine samples were smaller than those in abnormal wine samples, and the particle size of foreign particles in normal wine samples was less than 100μm. Relevant data show that the minimum size that most people can see within a visual distance of 25cm is about 100μm. Therefore, most of the particles in wine samples that pass the light inspection are less than 100μm. Therefore, for the discussion of the particle size of insoluble particles, 100μm was selected as the judgment standard. Foreign particles larger than 100μm do not meet the appearance quality requirements of wine. However, whether there is a food safety risk requires further qualitative analysis of the foreign particles. The collected spectrum is searched and compared with the spectrum in the spectral library. The types of insoluble particles measured are mainly divided into: plastic fibers, protein starch, higher fatty acid esters, inorganic salts and other types (unknown substances), see Table 2 and Table 3. Among them, protein starch mainly comes from the fermentation process, and is dragged into the liquor body as the liquor is distilled; higher fatty acid esters are trace components of liquor, which may precipitate at low temperatures, but will dissolve in the liquor as the temperature rises. (The national standard requires that white flocculent precipitate or loss of gloss is allowed when the temperature is below 10°C, and it should gradually return to normal when it is above 10°C.) These two types of foreign particles mainly come from the food fermentation process, are endogenous substances, and the overall food safety risk is relatively small; the other type is plastic fiber: mainly microplastic particles and silk, cotton, nylon and other substances. This type of material mainly comes from the production environment and the bottle cap is broken and falls into the liquor during the capping process. Since this type of material is difficult to degrade, it poses a greater risk to the quality of the liquor; inorganic salts are mainly insoluble substances formed by metal ions migrating out during the storage of liquor and combining with acid ions in the liquor, which also poses a risk to the quality of liquor. When these two types are detected, it should be judged as a greater food safety risk.

[0052] Example 2

[0053] When the particle size of foreign matter in the wine is less than 100μm, a risk assessment must be conducted based on the number and size of the particles and the judgment results of professional light inspectors.

[0054] The risk assessment method for the number of insoluble particles in wine includes the following steps:

[0055] (1) The purchased 50 μm standard particle size material (500-1000 particles / ml) was diluted in clean liquor at a ratio of 100 times, 200 times, and 500 times. The samples were inspected by the light inspectors in the packaging workshop and judged whether they were qualified according to the liquor production standards. The evaluation results are shown in Table 4. 5 ml of liquor containing standard particle size materials of different dilution multiples was filtered through a silicon membrane under negative pressure, and the filtered silicon membrane was placed in a clean culture dish to dry naturally. The size of the silicon membrane was 1 cm×1 cm, and the pore size was 1 μm.

[0056] Table 4 Evaluation results of the lamp inspection method

[0057]

[0058]

[0059] (2) Obtain spectral images of standard particle size materials at different dilution times according to step (2) in Example 1.

[0060] (3) The number of insoluble particles in the standard particle size material with different dilution multiples in the spectral image obtained in step (2) was counted. Each sample was measured 8 times. The results of the insoluble particle number measurement of the particle size material with different dilution multiples are shown in Tables 5 and Figure 3 , Figure 4 , Figure 5 shown.

[0061] Table 5 Statistical results of different dilution multiples of particle size materials

[0062]

[0063] (4) Combining Table 4 and Table 5, when the standard particle size is diluted 100 times, the light inspectors can clearly see the standard particle size material floating in the solution, and the standard particle size material in the solution is about 19 particles / 5ml on average; when the standard particle size material is diluted 200 times, the light inspectors judge the foreign matter in the solution as 56% qualified and 44% unqualified, and the standard particle size material in the solution is about 13 particles / 5ml on average; when the standard particle size material is diluted 500 times, the light inspectors can judge the samples as qualified, and the standard particle size material in the solution is about 5 particles / 5ml. In summary, when the insoluble particles in the wine are less than 100μm, it is necessary to consider the impact of the number of insoluble particles on the appearance quality of the liquor.

Claims

1. A method for evaluating the risk of insoluble particles in wine, characterized in that: include: Step S1: collecting infrared spectrum images of the wine body, identifying the types of insoluble particles in the wine body, and judging whether the particles in the wine body meet the food safety requirements according to the identification results of the types of insoluble particles in the wine body; Step S2: Identify the number and particle size of insoluble particles in the wine, and determine whether the wine meets the wine quality appearance requirements based on the number and size of the insoluble particles in the wine; Step S3: reducing the risk of insoluble particles in the wine body according to the food safety determination result of the wine body and the determination result of the wine quality appearance requirement.

2. A method for evaluating the risk of insoluble particles in wine according to claim 1, characterized in that: The specific method of collecting the infrared spectrum image of the wine body and identifying the type of insoluble particles in the wine body in step S1 is: Step a: Evaluate the production nodes that may introduce visible foreign matter during the winemaking process and identify the target objects of visible foreign matter that may be introduced at each production node; Step b: preparing the target objects identified in step S1 into samples to be tested respectively; Step c: collecting infrared spectrum images of each sample to be tested; Step d: establishing an infrared spectrum library of insoluble particles in liquor according to the infrared spectrum images of each sample to be tested; Step e: Match the infrared spectrum image of the insoluble particle detection sample in the established insoluble particle infrared spectrum library, and identify the type of the insoluble particles according to the matching result.

3. The method for evaluating the risk of insoluble particles in wine according to claim 1, characterized in that: In step S2, the number and particle size of the insoluble particles in the wine are identified based on the light inspection method to determine whether the insoluble particles in the wine meet the appearance requirements of the wine quality.

4. The method for evaluating the risk of insoluble particles in wine according to claim 1, characterized in that: Step b specifically includes: Step Sb1: using a sand core filter device to filter the liquor containing insoluble particles through a filter membrane under negative pressure to enrich the insoluble particles; Step Sb2: Place the filter membrane in a culture dish to air-dry and then place it on a slide, and place the entire slide directly on the stage of an infrared microscope, adjust the instrument aperture illumination, and focus and stitch the image of the entire filter membrane; Step Sb3: Add liquid nitrogen to the microscopic infrared spectrometer, use the wizard function in the Omnipicta software to mark the particles of the entire filter membrane image spliced ​​in step Sb2, and collect spectra of the marked particles one by one.

5. A method for evaluating the risk of insoluble particles in wine according to claim 4, characterized in that: In step Sb1, the wine sample filtration volume is 5 to 20 ml, the filter membrane is a silicon membrane, the pore size of the silicon membrane is 1 μm, and the size is 1 cm×1 cm; the negative pressure of the filtration makes the filtration speed no higher than 5 ml / min.

6. The method for evaluating the risk of insoluble particles in wine according to claim 4, characterized in that: In step Sb2, the magnification of the infrared microscope is 150 times, and the conditions for clear focus are: upper illumination is 100, aperture illumination is 0, and lower illumination is 50; the width and height of the aperture are both 150um, and the angle is 0°.

7. The method for evaluating the risk of insoluble particles in wine according to claim 4, characterized in that: The amount of liquid nitrogen added in step Sb3 is about 500 ml. The acquisition mode of the microscopic infrared device is: transmission mode, the detector is: MCT detector, and the spectral range of the detector is 4000 cm -1 -675cm -1 The number of scans for collecting the single-beam spectrum of each particle is 16, and the single acquisition time is 3 seconds.

8. The method for evaluating the risk of insoluble particles in wine according to claim 1, characterized in that: The step S1 of judging whether the particles in the wine meet the food safety requirements according to the results of the category identification of the insoluble particles in the wine specifically includes: if the categories of the insoluble particles in the wine include one or more of protein, starch, and higher fatty acid esters, the wine meets the food safety requirements; if the categories of the insoluble particles in the wine are identified as microplastics, metal oxides, silk cloth, and flannel cloth, the wine does not meet the food safety requirements.

9. The method for evaluating the risk of insoluble particles in wine according to claim 1, characterized in that: Step S2 of identifying the number and particle size of insoluble particles in the wine body, and judging whether the wine body meets the wine quality appearance requirements based on the number and size of the insoluble particles in the wine body specifically includes: if there are insoluble particles with a particle size greater than 100 μm in the wine body, the wine body does not meet the wine quality appearance requirements; if there are no insoluble particles with a particle size greater than 100 μm in the wine body, judging whether the wine body meets the wine quality appearance requirements is combined with the number of insoluble particles.

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