Rapid detection method for food safety

Abstract

The invention provides a rapid detection method for food safety, and relates to the technical field of food safety. The rapid detection method for food safety specifically comprises the following steps: S1, collecting a sample; s2, splitting the sample; s3, initial reaction; s4, performing centrifugal separation; s5, carrying out secondary reaction; and S6, developing and observing. According to the method, harmful microorganisms and chemical substances in food can be detected on site through six steps, expensive professional equipment and complex operation are not needed, the detection cost and time are reduced, the convenience and response speed are improved, results can be interpreted in real time, food safety is ensured, potential risks can be rapidly screened, the method is suitable for various places such as supermarkets and restaurants, and the method is suitable for popularization and application. The problems that in the prior art, operation is complex, consumed time is long, portability is poor and sensitivity and specificity are limited are solved, detection efficiency and accuracy are improved, health of consumers is protected, and modernization of food safety management is promoted.

Description

Technical Field

[0001] The present invention relates to the technical field of food safety, and specifically to a rapid detection method for food safety. Background Art

[0002] Food is a substance for people to eat or drink, including edible items derived from animals, plants, microorganisms or synthesis, with a wide variety, such as staple foods, fruits and vegetables, meat and aquatic products, dairy products, beverages and processed foods, etc. The main purpose of food safety detection is to ensure the quality and safety of food and protect consumers' health, including preventing the spread of diseases, reducing chemical pollution, ensuring compliance, enhancing consumers' trust and protecting the environment. By detecting harmful microorganisms and chemical substances in food, food safety detection helps prevent foodborne diseases, avoid chemical hazards, ensure compliance in the process of food production, processing, transportation and sales, while enhancing the brand reputation and market competitiveness of enterprises and promoting sustainable development.

[0003] Existing food safety detection technologies include two major categories: microbial detection and chemical detection. Microbial detection methods include cultivation methods, PCR and immunological detections such as ELISA; chemical detection methods include chromatography, spectroscopy and biosensors. These methods are costly because of the high prices of advanced equipment and consumables; they are operationally complex, especially for chromatography and PCR which require professionals and complex procedures and are not suitable for on-site rapid detection; they are time-consuming, for traditional methods such as cultivation methods which take several days and are not applicable to scenarios requiring rapid response; they have poor portability, as many devices are large and heavy and inconvenient to use on-site in supermarkets, restaurants, etc.; in addition, some rapid detection methods such as biosensors may have a high false positive or false negative rate, that is, the sensitivity and specificity are limited. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a rapid detection method for food safety, which solves the problems of high cost, difficult operation and long time consumption existing in the prior art.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions: A rapid detection method for food safety specifically includes the following steps:

[0006] S1. Sample collection

[0007] Collect food samples aseptically, and use sterile cotton swabs or pipettes to collect 1 - 2 grams of solid samples or 2 - 3 milliliters of liquid samples;

[0008] S2. Sample lysis

[0009] Add the collected samples into 5 mL of broad-spectrum lysis solution and mix well for 1 - 2 minutes;

[0010] S3. Initial reaction

[0011] Add the mixed sample solution to 1 mL of the corresponding initial reaction reagent, mix well for 1 - 2 minutes, then let the mixture stand for 2 minutes to complete the initial reaction;

[0012] S4. Centrifugal separation

[0013] Put the mixture after the initial reaction into a centrifuge and centrifuge at 3000 rpm for 2 minutes to separate the intermediate product, then carefully transfer the supernatant to a clean reaction tube;

[0014] S5. Secondary reaction

[0015] Add 1 mL of the supernatant to 1 mL of the corresponding secondary reaction reagent, mix well for 1 - 2 minutes, then place the reaction tube in a constant temperature water bath at 37 °C for 5 minutes to ensure that the reaction proceeds completely;

[0016] S6. Color development and observation

[0017] Add 1 mL of the reaction mixture to 1 mL of the corresponding color - developing reagent, mix well for 1 - 2 minutes, and observe the final color change.

[0018] Preferably, the broad - spectrum lysate consists of 1% Triton X - 100, 0.5 M NaCl, 10 mM Tris - HCl (pH 8.0), and 1 mM EDTA (pH 8.0).

[0019] Preferably, the initial reaction reagent includes 10 mM NaOH and 1% L - cysteine for detecting Salmonella, 10 mM HCl and 1% lactose for detecting Escherichia coli, 1 mM polyethyleneimine for detecting mycotoxins, and 1 mM nitrate reductase for detecting nitrites.

[0020] Preferably, the secondary reaction reagent includes 1 mM 3,3’,5,5’ - tetramethylbenzidine (TMB) and 1 mM H 2 O 2 for detecting Salmonella, 1 mM dimethylaminoazobenzene (DAB) and 1 mM H 2 O 2 for detecting Escherichia coli, 1 mM methyl red for detecting mycotoxins, 1 mM o - phenanthroline and 1 mM FeSO 4 for detecting nitrites.

[0021] Preferably, the color - developing reagent includes 1 mM iron ion solution (FeCl 3 ) for detecting Salmonella, 1 mM hydrogen peroxide (H 2 O2 ) is used to detect Escherichia coli, 1 mM sodium hydroxide (NaOH) is used to detect mycotoxins, and 1 mM iron(III) chloride (FeCl 3 ) is used to detect nitrites.

[0022] Preferably, the result of the detection method is judged by visually observing the color change in the reaction tube or using a color comparison card attached to the device for a more accurate concentration range judgment.

[0023] The present invention provides a rapid detection method for food safety. It has the following beneficial effects:

[0024] The present invention provides a rapid detection method for food safety. From sample collection to obtaining the final result, the whole process takes no more than 15 minutes, which is suitable for on-site rapid detection. The steps are simple, without the need for complex laboratory equipment or professional technicians, and ordinary consumers can easily operate it. The cost is low, the sensitivity is high, without the need for expensive equipment. Through multiple stages of biochemical reactions, the possibility of false positive or false negative results is reduced, the accuracy of detection is improved, it is convenient to carry and use on-site, and the final result is visually displayed through color change, which is convenient for users to judge without the assistance of complex instruments. Specific embodiments

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present invention.

[0026] The embodiments of the present invention provide a rapid detection method for food safety, which specifically includes the following steps:

[0027] S1. Sample collection

[0028] Sterilely collect food samples, and use sterile cotton swabs or pipettes to collect 1 - 2 grams of solid samples or 2 - 3 milliliters of liquid samples;

[0029] S2. Sample lysis

[0030] Add the collected samples to 5 mL of broad-spectrum lysis buffer and mix well for 1 - 2 minutes;

[0031] S3. Initial reaction

[0032] Add the mixed sample lysate to 1 mL of the corresponding initial reaction reagent, mix well for 1 - 2 minutes, and then let the mixture stand for 2 minutes to complete the initial reaction;

[0033] S4. Centrifugal separation

[0034] Transfer the mixture after the initial reaction into a centrifuge and centrifuge at 3000 rpm for 2 minutes to separate the intermediate product, and then carefully transfer the supernatant to a clean reaction tube;

[0035] S5. Secondary reaction

[0036] Add 1 mL of the supernatant to 1 mL of the corresponding secondary reaction reagent, mix well for 1 - 2 minutes, and then place the reaction tube in a constant temperature water bath at 37 °C for 5 minutes to ensure complete reaction;

[0037] S6. Color development and observation

[0038] Add 1 mL of the reacted mixture to 1 mL of the corresponding color development reagent, mix well for 1 - 2 minutes, and observe the final color change.

[0039] The broad - spectrum lysis solution consists of 1% Triton X - 100, 0.5 M NaCl, 10 mM Tris - HCl (pH 8.0), and 1 mM EDTA (pH 8.0). The initial reaction reagents include 10 mM NaOH and 1% L - cysteine for detecting Salmonella, 10 mM HCl and 1% lactose for detecting Escherichia coli, 1 mM polyethyleneimine for detecting mycotoxins, and 1 mM nitrate reductase for detecting nitrites. The secondary reaction reagents include 1 mM 3,3’,5,5’ - tetramethylbenzidine (TMB) and 1 mM H2O2 for detecting Salmonella, 1 mM dimethylaminoazobenzene (DAB) and 1 mM H2O2 for detecting Escherichia coli, 1 mM methyl red for detecting mycotoxins, and 1 mM o - phenanthroline and 1 mM FeSO4 for detecting nitrites. The color development reagents include 1 mM iron ion solution (FeCl3) for detecting Salmonella, 1 mM hydrogen peroxide (H2O2) for detecting Escherichia coli, 1 mM sodium hydroxide (NaOH) for detecting mycotoxins, and 1 mM iron chloride (FeCl3) for detecting nitrites. The results of the detection method are judged by visually observing the color change in the reaction tube or using the color comparison card provided with the equipment for more accurate determination of the concentration range.

[0040] Specifically: The present invention provides a method for rapid food safety detection. Its significant advantage is that the total time from sample collection to the interpretation of the final result in the entire detection process does not exceed 15 minutes, which is particularly suitable for food safety inspection scenarios that require rapid response, such as supermarkets, restaurants, or home kitchens, etc. This rapid detection ability is of great significance for early detection of potential hazards in food and timely taking countermeasures, and can significantly reduce the health risks caused by consuming contaminated food. For example, in a supermarket, the inspectors can quickly spot-check the newly stocked food to ensure its quality and safety, prevent unqualified products from entering the market, and thus protect the health of consumers.

[0041] The operation of this method is simple and does not rely on costly laboratory equipment or highly professional operators. Ordinary consumers can also easily complete it. This user-friendly design greatly reduces the threshold of food safety detection, enabling more individuals and institutions to participate in the supervision and management of food safety. For example, household users can use this method to detect the food at home to ensure the safety of daily diet; restaurant staff can conduct rapid detection before food processing to avoid using contaminated ingredients, thereby improving the quality and safety of catering services. In addition, this method is applicable to the detection of various food types, including solid and liquid samples, covering a wide range of food safety inspection requirements.

[0042] The careful proportioning and selection of the broad-spectrum lysis solution, initial reaction reagent, secondary reaction reagent, and chromogenic reagent ensure the sensitivity and specificity of the detection, effectively reducing the occurrence of false positive or false negative results and improving the reliability of the detection. The components of the broad-spectrum lysis solution include 1% Triton X-100, 0.5 M NaCl, 10 mM Tris-HCl (pH 8.0), and 1 mM EDTA (pH 8.0). These components can effectively destroy the cell walls of various microorganisms in food and release the target detection substances. The selection of the initial reaction reagent has also been optimized according to different detection targets. For example, 10 mM NaOH and 1% L-cysteine are used to detect Salmonella, 10 mM HCl and 1% lactose are used to detect Escherichia coli, 1 mM polyethyleneimine is used to detect mycotoxins, and 1 mM nitrate reductase is used to detect nitrites. These reagents can specifically react with the target substances and provide the necessary conditions for subsequent detection steps.

[0043] The selection of the secondary reaction reagent has also been optimized according to different detection targets. For example, 1 mM 3,3’,5,5’-tetramethylbenzidine (TMB) and 1 mM H 2 O 2 are used to detect Salmonella, 1 mM dimethylaminoazobenzene (DAB) and 1 mM H 2 O 2For detecting Escherichia coli, 1 mM methyl red is used for detecting mycotoxins, 1 mM o-phenanthroline and 1 mM FeSO 4 are used for detecting nitrites. These reagents can further react with the target substances to produce colorimetric products that can be observed under specific conditions. For example, TMB and H 2 O 2 can react with specific enzymes produced by Salmonella to produce blue or green colorimetric products; DAB and H 2 O 2 can react with specific enzymes produced by Escherichia coli to produce red colorimetric products; methyl red can react with mycotoxins to produce yellow or orange colorimetric products; o-phenanthroline and FeSO4 can react with nitrites to produce purple or blue colorimetric products. Through these colorimetric reactions, the detection results can be visually displayed, facilitating user interpretation.

[0044] The components of the colorimetric reagents have also been optimized according to different detection targets. For example, 1 mM iron ion solution (FeCl 3 ) is used for detecting Salmonella, 1 mM hydrogen peroxide (H 2 O 2 ) is used for detecting Escherichia coli, 1 mM sodium hydroxide (NaOH) is used for detecting mycotoxins, and 1 mM iron chloride (FeCl 3 ) is used for detecting nitrites. These colorimetric reagents can further react with the secondary reaction products to produce stable and significantly color-changing final products. For example, FeCl 3 can react with the colorimetric products produced by Salmonella to produce dark blue or black final products; H 2 O 2 can react with the colorimetric products produced by Escherichia coli to produce brown or black final products; NaOH can react with the colorimetric products produced by mycotoxins to produce red or purple final products; FeCl 3 can react with the colorimetric products produced by nitrites to produce yellow or green final products. These color changes are not only intuitive but also allow for more accurate determination of the concentration range through the color comparison card included with the device, further improving the accuracy and scientific nature of the detection results.

[0045] In addition, the method of the present invention has low cost and does not require expensive equipment and consumables. The components of the broad-spectrum lysis solution, the initial reaction reagent, the secondary reaction reagent, and the color-developing reagent are all relatively common and reasonably priced, and can be mass-produced and widely applied to various food safety detection scenarios. For example, supermarkets can use this method for daily food quality control to ensure the safety of all food items on the shelves; restaurants can conduct rapid tests before food processing to avoid using contaminated ingredients; and household users can use this method to detect the food at home to ensure the safety of daily diet. By reducing the detection cost, this method can be widely promoted, thereby improving the food safety level of the whole society.

[0046] The portability of this method is also a great advantage. The detection equipment with a small size and light weight is easy to carry and suitable for various on-site detection occasions. For example, food safety inspectors can carry this equipment during field inspections to conduct on-site detections on markets, catering places, etc., and promptly discover problem foods and take measures. This portability not only improves the detection efficiency but also enhances the ability of food safety supervision, making the inspection work more flexible and efficient.

[0047] In summary, the present invention provides a method for rapid food safety detection, which has the following advantages:

[0048] From sample collection to final result interpretation, the whole process takes no more than 15 minutes, which is especially suitable for food safety inspection scenarios that require rapid response. It does not require complex laboratory equipment or professional technicians, and ordinary consumers can easily complete the detection, reducing the threshold of food safety detection. Through multiple stages of biochemical reactions and carefully formulated reagents, the possibility of false positive or false negative results is reduced, improving the accuracy and reliability of the detection. The reagents and equipment used have low costs, are easy to mass-produce and widely apply, reducing the overall cost of food safety detection. The detection equipment with a small size and light weight is easy to carry and suitable for various on-site detection occasions, enhancing the flexibility and efficiency of food safety supervision. The detection results are visually displayed through color changes, and users can observe with the naked eye or use the color comparison card attached to the equipment for more accurate interpretation, which is convenient for understanding and application.

[0049] With the above characteristics, the present invention can not only improve the speed and accuracy of food safety detection, but also be widely applied to various scenarios, providing an efficient and practical solution for ensuring public health and maintaining food safety. The popularization and application of this rapid detection method will significantly enhance the level of food safety management, reduce the health risks caused by consuming contaminated food, enhance consumers' confidence in food safety, and promote the sustainable development of the food industry. At the same time, this method can also improve the brand image and market competitiveness of enterprises, bringing more business opportunities and social trust to enterprises. In short, the present invention has important application value and broad development prospects in the field of food safety technology.

[0050] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for rapid food safety detection, characterized in that: The specific steps include: S1. Sample collection Aseptically collect food samples using a sterile cotton swab or pipette to collect 1-2 grams of solid samples or 2-3 ml of liquid samples; S2. Sample lysis Add the collected sample to 5 mL of broad-spectrum lysis buffer and mix thoroughly for 1-2 minutes; S3. Initial Response Add the mixed sample solution to 1 mL of the corresponding initial reaction reagent, mix thoroughly for 1-2 minutes, and then let the mixture stand for 2 minutes to allow the initial reaction to complete; S4. Centrifugal separation Place the mixture after the initial reaction in a centrifuge and centrifuge at 3000 rpm for 2 minutes to separate the intermediate product, and then carefully transfer the supernatant to a clean reaction tube; S5. Secondary reaction Add 1 mL of supernatant to 1 mL of the corresponding secondary reaction reagent, mix thoroughly for 1-2 minutes, and then place the reaction tube in a constant temperature water bath at 37°C for 5 minutes to ensure that the reaction is complete; S6. Color observation Add 1 mL of the reaction mixture into 1 mL of the corresponding color developing reagent, mix thoroughly for 1-2 minutes, and observe the final color change.

2. A method for rapid food safety detection according to claim 1, characterized in that: The broad-spectrum lysis buffer consists of 1% Triton X-100, 0.5 M NaCl, 10 mM Tris-HCl (pH 8.0) and 1 mM EDTA (pH 8.0).

3. A method for rapid food safety detection according to claim 1, characterized in that: The initial reaction reagents include 10 mM NaOH and 1% L-cysteine ​​for detecting Salmonella, 10 mM HCl and 1% lactose for detecting Escherichia coli, 1 mM polyethyleneimine for detecting mycotoxins, and 1 mM nitrate reductase for detecting nitrite.

4. A method for rapid food safety detection according to claim 1, characterized in that: The secondary reaction reagents include 1mM 3,3',5,5'-tetramethylbenzidine (TMB) and 1mM H2O2 for detecting Salmonella, 1mM dimethylaminoazobenzene (DAB) and 1mM H2O2 for detecting Escherichia coli, 1mM methyl red for detecting mycotoxins, and 1mM o-phenanthroline and 1mM FeSO4 for detecting nitrite.

5. A method for rapid food safety detection according to claim 1, characterized in that: The color developing reagent includes 1 mM iron ion solution (FeCl3) for detecting Salmonella, 1 mM hydrogen peroxide (H2O2) for detecting Escherichia coli, 1 mM sodium hydroxide (NaOH) for detecting mycotoxins, and 1 mM ferric chloride (FeCl3) for detecting nitrite.

6. A method for rapid food safety detection according to claim 1, characterized in that: The results of the detection method are interpreted by visually observing the color change in the reaction tube, or by using the color comparison card attached to the device for more accurate concentration range interpretation.