Method for detecting heavy metals in food

Abstract

The invention relates to a food heavy metal detection method, which belongs to the technical field of food safety, and comprises the following steps: step 1, to-be-detected food in a fluid or solid-liquid mixed form passes through a food transportation channel, and passes through a plurality of monitoring modules around the food transportation channel; 2, the transmitters of the plurality of monitoring modules emit light to the food transportation pipeline, and the receivers of the plurality of monitoring modules are used for receiving reflected light formed by the light emitted by the corresponding transmitters and analyzing spectrums; 3, the receivers of the multiple monitoring modules upload the spectrum to a control module, the control module judges whether the spectrum exceeds a reference range or not, and an alarm is given out when the judgment result is negative. The probability of insufficient irradiation caused by shielding of a part needing to be detected due to dense distribution of food is reduced, the screening detection accuracy is improved, the quality of outgoing food is ensured, and a good image of an enterprise brand is maintained.

Description

Technical Field

[0001] The invention belongs to the technical field of food safety, and in particular relates to a method for detecting heavy metals in food. Background Art

[0002] In recent years, food safety has become a global focus. Heavy metal pollution such as lead, mercury, cadmium, arsenic, etc. has potential hazards to human health. Long-term intake of these heavy metals may lead to serious health problems such as poisoning, organ damage, nervous system problems and cancer. For this reason, the food industry, especially the snack production industry, needs to test food for heavy metal pollution.

[0003] At present, in the food production process, it is impossible to detect such pollutants in real time, and it can only be achieved by random inspection by heavy metal detectors after the food processing is completed. But in fact, the drawbacks of the random inspection system itself are still not equivalent to daily supervision. For this reason, Chinese patent CN112378897B discloses a heavy metal detection device for food production, including a bracket and a detection mechanism arranged on the bracket, the detection mechanism includes a heavy metal detection device arranged on the bracket and a control unit electrically connected to the heavy metal detection device, the heavy metal detection device includes a shell and a perforation for the food material tube to pass through, the tube section of the food material tube located in the shell is constructed as a heavy metal detection tube section, a light source is arranged in the shell to emit detection light to the light-transmitting part of the heavy metal detection tube section, the detection light passes through the heavy metal detection tube section to form an emitted light, a spectroscope receives the emitted light and forms a decomposed light, a CMOS sensor for receiving a spectrum is arranged on the side where the decomposed light is emitted from the spectroscope, the CMOS sensor is electrically connected to the control unit and transmits spectrum information to the control unit in real time, and the control unit is configured to determine whether the sample contains heavy metal elements according to a preset atomic spectrum and / or ion spectrum;

[0004] However, the above scheme relies on direct irradiation of food with light to complete the detection. However, food, especially liquid food in the processing process or food that does not have a solid shape, such as snacks such as jelly containing solids and liquids, is not evenly distributed during transportation. At this time, when the direction of the emitted and received light is relatively single, for areas where the food to be detected is densely distributed, there is a probability that the light cannot fully bombard the heavy metals therein to form a spectrum, resulting in the spectral reception results being unable to well reflect the heavy metal content, or the light cannot penetrate the food to the extent that the spectrum changes, resulting in the inability to detect heavy metals through the spectrum. Therefore, a food heavy metal detection method with sufficient detection light irradiation and accurate detection results is needed. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a method for detecting heavy metals in food, which has the characteristics of sufficient detection light irradiation and accurate detection results.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A method for detecting heavy metals in food comprises the following steps:

[0008] Step 1: The food to be tested in the form of a fluid or a solid-liquid mixture passes through a food transport channel and passes through a number of monitoring modules surrounding the food transport channel;

[0009] Step 2: The transmitters of several monitoring modules emit light to the food transportation pipeline, and the receivers of several monitoring modules are used to receive the reflected light formed by the light emitted by the corresponding transmitter and analyze the spectrum;

[0010] Step 3: The receivers of several monitoring modules upload the spectrum to the control module, and the control module determines whether the spectrum exceeds the reference range and issues an alarm if the judgment result is no.

[0011] As a preferred technical solution of the present invention, the step 2 further includes: a moving module surrounding the food transportation channel drives a plurality of monitoring modules to move along itself.

[0012] As a preferred technical solution of the present invention, the step one also includes: the center of gravity detection module is used to detect the distribution of the center of gravity of food in the food transportation channel, and upload the detection result to the control module; the step two also includes: the control module determines whether the center of gravity deviation exceeds the threshold value according to the detection result, and the control module determines the center of gravity distribution orientation if the judgment result is no, and instructs the moving module to drive the monitoring module to move to the center of gravity distribution orientation.

[0013] As a preferred technical solution of the present invention, the step one also includes: the center of gravity detection module is used to detect the distance between the center of gravity of the food in the food transportation channel and the center of the food transportation channel and upload it to the control module, and the step two also includes: the control module calculates the ratio of the distance between the center of gravity of the food and the center of the food transportation channel to the radius of the food transportation channel, and the control module adjusts the number of monitoring modules driven to move to the center of gravity distribution position according to the size of the ratio.

[0014] As a preferred technical solution of the present invention, the step one also includes: the center of gravity detection module is used to detect the distance a between the center of gravity of the food in the food transportation channel and the center of the food transportation channel and upload it to the control module, and the step two also includes: the control module calculates the ratio of the distance a between the center of gravity of the food and the center of the food transportation channel to the radius r of the food transportation channel, and the control module instructs the moving module to move the n monitoring modules to the center of gravity distribution position, where n = Z (a / r×c), c is the number of monitoring modules.

[0015] As a preferred technical solution of the present invention, the step one further comprises: inputting values ​​of r and c in the control panel.

[0016] As a preferred technical solution of the present invention, step two also includes: the control module determines whether the center of gravity deviation exceeds the threshold value based on the detection result, the control module determines whether the center of gravity distribution orientation in the five judgments is consistent when the judgment result is no for five consecutive times, and instructs the moving module to drive the monitoring module to move to the center of gravity distribution orientation when the judgment result is yes.

[0017] The beneficial effects of the present invention are:

[0018] (1) By surrounding the food transport channel with several monitoring modules, food spectrum information can be obtained from different angles, reducing the probability of insufficient irradiation caused by irradiation in a single direction and improving the accuracy of the detection results;

[0019] (2) By sliding a plurality of monitoring modules on the mobile module, when the angle of the monitoring module relative to the food transport channel needs to be adjusted, manual operation by the operator is not required, thereby improving the convenience of use;

[0020] (3) By making the control module determine whether the center of gravity deviation exceeds the threshold according to the center of gravity detection result, the instructing moving module to drive the monitoring module to move to the center of gravity distribution position, so that for the area where the food to be tested is densely distributed, more monitoring modules can be concentrated for detection, thereby reducing the probability of insufficient irradiation caused by the dense distribution of food causing the parts to be tested to be blocked, improving the accuracy of the detection results, enhancing the accuracy of screening detection, ensuring the quality of the food leaving the factory, and maintaining the good image of the corporate brand. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0022] Figure 1 It is a structural schematic diagram of the present invention;

[0023] Figure 2 It is a structural schematic diagram of the present invention;

[0024] Figure 3 This is a schematic diagram of the structure when the monitoring modules of the present invention are concentrated on one side of the food transportation channel;

[0025] Description of main component symbols:

[0026] In the figure: 1. Food transportation channel; 2. Monitoring module; 3. Mobile module. DETAILED DESCRIPTION

[0027] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0028] See also Figure 1-3 , a method for detecting heavy metals in food, comprising the following steps:

[0029] Step 1: The food to be tested in the form of a fluid or a solid-liquid mixture passes through the food transport channel 1 and passes through a plurality of monitoring modules 2 surrounding the food transport channel 1;

[0030] Specifically, the detection device includes a food transport channel 1, a control module and several monitoring modules 2, the control module is electrically connected to the several monitoring modules 2, and the food transport channel 1 is used to transport food.

[0031] During step one, step two is performed: the transmitters of the plurality of monitoring modules 2 emit light to the food transport pipeline, and the receivers of the plurality of monitoring modules 2 are used to receive the reflected light formed by the light emitted by the corresponding transmitter and analyze the spectrum;

[0032] Specifically, a plurality of monitoring modules 2 are arranged around the food transport channel 1, and any monitoring module 2 includes a corresponding transmitter and a receiver, the transmitter is used to emit light to the food transport pipeline, and the receiver is used to receive the reflected light formed by the light emitted by the corresponding transmitter and analyze the spectrum;

[0033] In this embodiment, the food transport channel 1 selects a cylindrical transport pipe or a long flat conveyor belt according to the type of food to be detected. When the food to be detected is a liquid food, or the liquid substance accounts for a high proportion, which is not convenient for conveyor belt transportation, a cylindrical transport pipe is used. When the food is solid, or the liquid substance accounts for a small proportion, a conveyor belt is used. Compared with the transport pipe, the conveyor belt does not have any obstruction between the food and the monitoring module 2, and the monitoring module 2 can directly detect the food.

[0034] Then, step three is performed: the receiver uploads the spectrum to the control module, and the control module determines whether the spectrum exceeds the reference range and issues an alarm if the judgment result is no;

[0035] Regarding the manner in which a plurality of monitoring modules 2 are arranged around the food transport channel 1, for the cylindrical transport pipeline, in this embodiment, there are four monitoring modules 2 in total, and the four monitoring modules 2 are distributed around the cylindrical food transport channel 1 in a circular array, that is, the four monitoring modules 2 are equidistant from the axis of the cylindrical food transport channel 1, and each of the four connecting lines between the four monitoring modules 2 and the axis of the cylindrical food transport channel 1 is perpendicular to the adjacent connecting lines; for the conveyor belt, the four monitoring modules 2 are distributed on the upper surface of the conveyor belt in a semi-circular array, and the conveyor belt is placed horizontally, and the four monitoring modules 2 are not lower than the upper surface of the conveyor belt, and each of the four connecting lines between the four monitoring modules 2 and the center line of the conveyor belt is at an angle of 45° to the adjacent connecting line, and at this time, the four monitoring modules 2 are distributed in the space of the upper half of the conveyor belt;

[0036] In the present invention, the method for detecting the heavy metal content in food is laser induced breakdown spectroscopy, that is, a laser light source is used to induce the heavy metal elements in the food material to produce an atomic spectrum or an ion spectrum, and then the spectrum information is received by a CMOS sensor. The spectrum information is compared with the preset atomic spectrum information or ion spectrum information by a control unit, so as to detect the heavy metal elements in the food material;

[0037] At the same time, the transmitter of each monitoring module 2 is a laser light source set to aim at the food transportation channel 1, and the receiver is an aligned CMOS sensor. When the light source of the transmitter irradiates the laser to the aligned food transportation channel 1, the laser induces the heavy metal elements in the food material to produce an atomic spectrum or an ion spectrum, and reflects the light containing the spectrum information in all directions, and the part reflected toward the receiver further receives the spectrum information through the CMOS sensor;

[0038] For the cylindrical transport pipeline, the pipeline is made of transparent material. The transmitter sends light to the food transport channel 1. The light passes through the transparent pipeline wall, inducing the heavy metal elements in the food material to produce atomic spectra or ion spectra. Then the light carrying the spectral information propagates around through the transparent pipeline wall and is received by the receiver. Then the receiver uploads the spectrum to the control module. The control module compares the spectrum with the preset atomic spectrum information or ion spectrum information through the control unit to determine whether the spectrum exceeds the reference range, and issues an alarm when the judgment result is no, thereby completing the heavy metal detection.

[0039] During transportation, the distribution of food will change due to random factors, resulting in uneven distribution. For areas where the food to be detected is densely distributed, there is a probability that the light cannot fully bombard the heavy metals therein to form a spectrum, resulting in the spectrum reception result not being able to well reflect the heavy metal content, or the light cannot penetrate the food to the extent that the spectrum changes, resulting in the inability to detect heavy metals through the spectrum. At this time, through the surrounding several monitoring modules 2, several monitoring modules 2 perform heavy metal detection on several locations in the food transportation channel 1. For densely distributed areas, light can be injected from different angles, and then the food spectrum information can be obtained from different angles, reducing the probability of insufficient irradiation caused by irradiation in a single direction;

[0040] By surrounding the food transport channel 1 with a plurality of monitoring modules 2, food spectrum information can be obtained from different angles, thereby reducing the probability of insufficient irradiation caused by irradiation in a single direction and improving the accuracy of the detection results.

[0041] In some cases, it is necessary to adjust the angle of the monitoring module 2 relative to the food transportation channel 1 according to the distribution in the food transportation channel 1. In the above structure, the monitoring module 2 does not have a motion function and needs to be manually adjusted by the operator. Therefore, step 2 also includes: the mobile module 3 surrounding the food transportation channel 1 drives a plurality of monitoring modules 2 to move along itself.

[0042] Specifically, the detection device includes a mobile module 3, which is arranged around the food transportation channel 1, and a plurality of monitoring modules 2 are slidably arranged on the mobile module 3, and the mobile module 3 drives the monitoring modules 2 to move along itself;

[0043] The mobile module 3 includes a circular track arranged around the food transport passage 1, and a plurality of sliders arranged on the circular track corresponding to the monitoring modules 2. The sliders have their own drivers, which drive the sliders to move along the circular track. Each monitoring module 2 is arranged on a corresponding slider, and ensures that it is arranged toward the food transport passage 1 after being arranged on the slider. The control module is electrically connected to the driver of each slider, and drives the slider to move along the circular track by instructing the driver, thereby driving the monitoring module 2 to move along the mobile module 3.

[0044] At the same time, in this embodiment, the four monitoring modules 2 are distributed in a circular array around the cylindrical food transportation channel 1, or when the food transportation channel 1 is a conveyor belt, they are distributed in a semi-circular array on the upper surface of the conveyor belt. Therefore, in order to ensure that the distance between the monitoring module 2 and the food to be detected after movement is close to that before movement, the circular track is a circular track surrounding the food transportation channel 1, and the axis of the circular track coincides with the axis of the cylindrical food transportation channel 1, or coincides with the center line of the conveyor belt. When the food transportation channel 1 is a cylindrical transportation pipeline, the initial state of the four sliders is arranged on the circular track in a circular array, that is, the four connecting lines of the four sliders and the axis of the cylindrical food transportation channel 1, each connecting line is perpendicular to the adjacent connecting lines; when the food transportation channel 1 is a conveyor belt, the four sliders are distributed in a semi-circular array on the upper surface of the conveyor belt, the conveyor belt is placed horizontally, and the four sliders are not lower than the upper surface of the conveyor belt. For the four connecting lines of the slider and the center line of the conveyor belt, the angle between each connecting line and the adjacent connecting line is 45°, and the four sliders are distributed in the space of the upper half of the conveyor belt;

[0045] For areas where the food to be detected is densely distributed, more monitoring modules 2 need to be concentrated for detection, which reduces the probability of insufficient irradiation caused by the dense distribution of food and the obstruction of the part to be detected. For this reason, step one also includes: the center of gravity detection module is used to detect the distribution of the center of gravity of the food in the food transportation channel 1, and upload the detection result to the control module; step two also includes: the control module determines whether the center of gravity deviation exceeds the threshold according to the detection result, and the control module determines the center of gravity distribution direction when the judgment result is no, and instructs the moving module 3 to drive the monitoring module 2 to move to the center of gravity distribution direction;

[0046] Specifically, the control module is electrically connected to the mobile module 3, and the control module is electrically connected to the center of gravity detection module, which is used to detect the distribution of the center of gravity of the food in the food transportation channel 1, and upload the detection result to the control module. The control module determines whether the center of gravity deviation exceeds the threshold value according to the detection result, and determines the distribution direction of the center of gravity if the judgment result is yes. The control module instructs the mobile module 3 to drive the monitoring module 2 to move to the distribution direction of the center of gravity;

[0047] In this embodiment, in a plane perpendicular to the axis of the food transport channel 1, the food transport channel 1 is divided into four areas along the center of the circle, each area has four dividing lines with adjacent areas, each dividing line has an angle of 90° with the adjacent connecting line, and the angle between the dividing line or the extension of the dividing line and the ground is 45°. At this time, the four areas are respectively located above, below and on both sides of the food transport channel 1. At this time, the four areas constitute the upper detection area, the lower detection area, the left detection area and the right detection area;

[0048] The center of gravity detection module is used to detect the distribution of the center of gravity of the food in the food transportation channel 1 every ten seconds. After receiving the distribution, the control module determines the distribution direction of the center of gravity. There are four results of the direction, namely, the center of gravity is in the upper detection area, the lower detection area, the left detection area or the right detection area. At this time, the control module instructs the moving module 3 to drive the monitoring module 2 to move to the distribution direction of the center of gravity;

[0049] At the same time, the center of gravity detection module is used to detect the distance between the center of gravity of the food in the food transportation channel 1 and the center of the food transportation channel 1 and upload it to the control module. The control module calculates the ratio of the distance between the center of gravity of the food and the center of the food transportation channel 1 to the radius of the food transportation channel 1. The control module adjusts the number of monitoring modules 2 driven to move to the center of gravity distribution position according to the ratio;

[0050] In the above process of adjusting the number of monitoring modules 2 driven to move to the position of the center of gravity distribution according to the size of the ratio, specifically, the center of gravity detection module is used to detect the distance a between the center of gravity of the food in the food transportation channel 1 and the center of the food transportation channel 1 and upload it to the control module, the control module calculates the ratio of the distance a between the center of gravity of the food and the center of the food transportation channel 1 and the radius r of the food transportation channel 1, and the control module instructs the moving module 3 to move n monitoring modules 2 to the position of the center of gravity distribution, wherein n=Z(a / r×c), that is, n is an integer of the calculation result of a / r×c, and c is the number of monitoring modules;

[0051] When the value of a is large, it means that the degree of gravity center deviation is large, and the food is concentrated in one place in the transportation pipeline. More monitoring modules 2 need to be concentrated at the gravity center distribution position. At this time, the value of a / r is large, and the value of n=Z(a / r×c) is large. When the control module instructs the moving module 3 to move n monitoring modules 2 to the gravity center distribution position, more monitoring modules 2 can be concentrated for detection in the area where the food to be detected is densely distributed;

[0052] When the value of a is small, it means that the degree of gravity center deviation is small, and the distribution of food in the transportation channel is relatively uniform. Concentrating too many monitoring modules 2 may cause some food in the channel to be missed. There is no need to concentrate more monitoring modules 2 at the gravity center distribution position. At this time, the value of a / r is small, and the value of n=Z(a / r×c) is small. When the control module instructs the moving module 3 to move n monitoring modules 2 to the gravity center distribution position, the gravity center deviation can be small, and the food transportation channel 1 can be evenly inspected;

[0053] When the control module determines that the center of gravity deviation does not exceed the threshold, the control module instructs a number of sliders to drive the monitoring module 2 to move to the initial state;

[0054] By allowing the control module to determine whether the center of gravity deviation exceeds the threshold based on the center of gravity detection result, the moving module 3 is instructed to drive the monitoring module 2 to move to the center of gravity distribution position, so that for areas where the food to be detected is densely distributed, more monitoring modules 2 can be concentrated for detection, thereby reducing the probability of insufficient irradiation caused by the dense distribution of food causing the parts to be detected to be blocked, thereby improving the accuracy of the detection results.

[0055] In order to facilitate the input of the values ​​of r and c, a control panel is also included. In step one, the control panel is used to input the values ​​of r and c.

[0056] In the process of the center of gravity detection module judging the center of gravity of food in the food transportation channel 1, the center of gravity of food may change over time. For example, when the food in the food transportation channel 1 is only gathered in a certain place in a short period of time, when the food passes through the center of gravity detection module and reaches the monitoring module 2, the food distribution has returned to uniformity or the gathering point has changed. At this time, the distribution of several monitoring modules 2 adjusted according to the center of gravity detection module is no longer applicable to the current food distribution in the food transportation channel 1, and the accuracy of the detection result is reduced. Therefore, in step 2: the control module judges whether the center of gravity deviation exceeds the threshold value according to the detection result, and the control module judges whether the center of gravity distribution orientation in the five judgments is consistent when the result of five consecutive judgments is no, and instructs the moving module 3 to drive the monitoring module 2 to move to the center of gravity distribution orientation when the judgment result is yes;

[0057] When the results of five consecutive uploads are judged to exceed the threshold and the distribution direction is consistent, it means that the food somewhere in the food transportation channel 1 is stably gathered in one place, and the probability of changes when moving to several monitoring modules 2 is low. At this time, the probability of the distribution of several monitoring modules 2 adjusted according to the center of gravity detection module no longer being suitable for the current food distribution in the food transportation channel 1 is reduced.

[0058] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for detecting heavy metals in food, characterized in that: The following steps are involved: Step 1: The food to be tested in the form of a fluid or a solid-liquid mixture passes through a food transport channel and passes through a number of monitoring modules surrounding the food transport channel; Step 2: The transmitters of several monitoring modules emit light to the food transportation pipeline, and the receivers of several monitoring modules are used to receive the reflected light formed by the light emitted by the corresponding transmitter and analyze the spectrum; Step 3: The receivers of several monitoring modules upload the spectrum to the control module, and the control module determines whether the spectrum exceeds the reference range and issues an alarm if the judgment result is yes.

2. A method for detecting heavy metals in food according to claim 1, characterized in that: The step 2 also includes: the moving module surrounding the food transportation channel drives a plurality of monitoring modules to move along itself.

3. A method for detecting heavy metals in food according to claim 2, characterized in that: The step one also includes: a center of gravity detection module is used to detect the distribution of the center of gravity of food in the food transportation channel, and upload the detection result to the control module; the step two also includes: the control module determines whether the center of gravity deviation exceeds the threshold value based on the detection result, and the control module determines the center of gravity distribution direction when the judgment result is no, and instructs the moving module to drive the monitoring module to move to the center of gravity distribution direction.

4. A method for detecting heavy metals in food according to claim 3, characterized in that: The step one also includes: a center of gravity detection module is used to detect the distance between the center of gravity of the food in the food transportation channel and the center of the food transportation channel and upload it to the control module; the step two also includes: the control module calculates the ratio of the distance between the center of gravity of the food and the center of the food transportation channel to the radius of the food transportation channel, and the control module adjusts the number of monitoring modules driven to move to the center of gravity distribution position according to the size of the ratio.

5. A method for detecting heavy metals in food according to claim 1, characterized in that: The step one also includes: a center of gravity detection module is used to detect the distance a between the center of gravity of the food in the food transportation channel and the center of the food transportation channel and upload it to the control module; the step two also includes: the control module calculates the ratio of the distance a between the center of gravity of the food and the center of the food transportation channel to the radius r of the food transportation channel, and the control module instructs the moving module to move n monitoring modules to the center of gravity distribution position, where n=Z(a / r×c), and c is the number of monitoring modules.

6. A method for detecting heavy metals in food according to claim 5, characterized in that: The step one also includes: inputting the values ​​of r and c in the control panel.

7. A method for detecting heavy metals in food according to claim 1, characterized in that: The step 2 also includes: the control module determines whether the center of gravity deviation exceeds the threshold value according to the detection result, and the control module determines whether the center of gravity distribution orientation in the five judgments is consistent if the judgment result is no for five consecutive times, and instructs the moving module to drive the monitoring module to move to the center of gravity distribution orientation when the judgment result is yes.

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