Method for detecting peroxide value and acid value of food

Abstract

The invention relates to a method for detecting the peroxide value and the acid value of food, and belongs to the technical field of detection instruments. Putting a to-be-detected sample into the reagent bottle, and then dropwise adding a detection reagent into the reagent bottle; in the process, a light source is used for irradiating the reagent bottle, and a sensor is used for receiving light reflected by the reagent in the reagent bottle; the control system detects the light received by the sensor; when the color of the received light is a preset value, dropwise adding of the detection reagent is stopped; recording a titration end point, and determining a peroxide value; the acid value can be measured by the same method, and the color of the solution judged by the titration end point for measuring the peroxide value is different. According to the invention, light is utilized to irradiate a reagent and a sensor is utilized to carry out color detection, so that automatic detection of a peroxide value and an acid value can be realized, the detection precision can be improved, automatic detection can be carried out for a long time, and the detection efficiency is improved; meanwhile, workers are prevented from inhaling gas with pungent smell, and harm of chemical reagents to experimenters is reduced.

Description

Technical Field

[0001] The invention relates to a method for detecting the peroxide value and acid value of food, belonging to the technical field of detection instruments. Background Art

[0002] In the quality testing of oils and fats and related products, peroxide value is a key indicator for assessing the degree of oil oxidation. Its value directly reflects whether the oil has become rancid, and is crucial for quality control and safety assurance in industries such as food and chemicals. Traditional methods for determining the peroxide value of oils primarily rely on manual titration. This method relies on the operator adding the test reagent dropwise to the oil using a burette and visually observing the color change of the solution to determine the titration endpoint. However, this manual operation has significant drawbacks. First, the accuracy of manual titration is significantly affected by the operator's subjective factors. Different operators have different sensitivity to color changes and judgment criteria, making it difficult to ensure the repeatability and accuracy of the measurement results. Second, the detection reagents during the titration process often have a pungent odor, and long-term exposure can pose a potential health hazard to the operator. Furthermore, manual operation is inefficient and cannot meet the needs of rapid testing of large quantities of samples. Therefore, developing an oil peroxide value determination instrument that can accurately determine the titration endpoint and realize automated detection has become an urgent need to solve the current bottleneck of detection technology. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for detecting the peroxide value and acid value of food to solve the above problems.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is: A method for detecting the peroxide value and acid value of food comprises placing a sample to be detected in a reagent bottle, and then dripping a detection reagent into the reagent bottle; during this process, using a light source to illuminate the reagent bottle, and using a sensor to receive light transmitted through the reagent in the reagent bottle; a control system detects the light received by the sensor; when the color of the received light reaches a preset value, dripping the detection reagent is stopped; recording the titration endpoint to determine the peroxide value; the same method can be used to determine the acid value, but the solution color determined by the titration endpoint is different from that used to determine the peroxide value.

[0005] A further improvement of the technical solution of the present invention is as follows: the detector has a rotating tray; a plurality of reagent bottle slots are arranged on the rotating tray, and through holes that allow light to pass through are arranged on two opposite sides of the reagent bottle slots; the light source and the sensor are located on both sides of the through holes on the reagent bottle slots.

[0006] A further improvement of the technical solution of the present invention is that the reagents in multiple reagent bottles can be tested at the same time.

[0007] A further improvement of the technical solution of the present invention is: using a detector to perform detection; the detection reagent dripping mechanism of the detector automatically drips the detection reagent into the reagent bottle.

[0008] A further improvement of the technical solution of the present invention is that the solution in the reagent bottle is stirred during the process of adding the detection reagent.

[0009] A further improvement of the technical solution of the present invention is: using magnetic stirring to stir the solution in the reagent bottle.

[0010] A further improvement of the technical solution of the present invention is as follows: the detection reagent dripping mechanism includes a rotating arm, a filling pump and a filling pipe; the rotating arm is driven to rotate by a servo motor; a filling nozzle is provided at the end of the rotating arm; one end of the filling pipe extends from the instrument housing, and the other end extends along the inside of the rotating arm and is connected to the filling nozzle.

[0011] A further improvement of the technical solution of the present invention is that, when in use, the filling pipe extends from the instrument housing and is connected to the filling reagent bottle.

[0012] A further improvement of the technical solution of the present invention is that: a plurality of detection reagent dropping mechanisms are provided.

[0013] A further improvement of the technical solution of the present invention is that the detection reagent dripping mechanism has a plurality of reagent filling nozzles.

[0014] Due to the adoption of the above technical solution, the technical effects achieved by the present invention are as follows: The method for detecting peroxide value and acid value of the present invention utilizes light irradiation and uses a sensor to perform light principle; during the process of adding reagents to the oil product, the color of the solution changes. By irradiating the solution with light and using a sensor to detect the color of the light reflected by the solution, the titration end point can be accurately determined.

[0015] The detection method of the present invention can realize automated detection by using a detector, does not require manual operation by staff, and the titration process is more accurate; at the same time, it can prevent staff from inhaling gases with pungent odors, reducing chemical reagent damage to experimenters. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the detector used in the present invention; Among them, 1. rotating arm, 2. rotating tray, 3. reagent bottle slot, 4. end cover. DETAILED DESCRIPTION

[0017] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.

[0018] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", "front end", "rear end", "two ends", "one end", "the other end", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limiting the present invention.

[0019] The invention discloses a method for detecting the peroxide value and acid value of food, which utilizes a light source to irradiate a solution and uses a sensor to monitor the light, thereby realizing automated detection through automatic comparison of light colors.

[0020] The main principle of the detection method of the present invention is as follows: during the process of adding a reagent to the solution to be tested, light is used to illuminate the solution; since the solution changes color during the addition process, the color of the light transmitted through the solution also changes, and the light is received by a sensor and compared with the preset color through the control system; when the extension of the light is consistent with the preset color comparison, the addition is stopped, and the peroxide value of the food can be calculated at this time; the same method can also be used to measure the acid value of the food, the only difference being that the color of the light at the titration end point is different.

[0021] The testing process primarily involves the following steps: First, the sample to be tested is placed in a reagent bottle. Then, the appropriate test reagent is added dropwise based on the desired amount (peroxide value or acid value). During this process, a light source continuously illuminates the reagent bottle, and a sensor receives the light transmitted through the reagent inside. As the reagent is added, the color of the sample changes. The control system detects the color of the light received by the sensor and compares it to a preset color. When the color reaches the preset value, the addition of the test reagent is stopped, and the titration endpoint is recorded to determine the value of the parameter being tested. This means that when testing the peroxide value, the specific value can be determined; when testing the acid value, the specific value can be determined.

[0022] When measuring the peroxide value, it is necessary to add the reagents chloroform + glacial acetic acid, which have a strong pungent odor and are toxic. This instrument does not require manual addition or manual observation of the color change of the solution. The staff does not need to inhale the gas with a pungent odor, which greatly reduces the harm of the reagents to the experimenters.

[0023] When measuring acid value, the titrant is potassium hydroxide or sodium hydroxide; phenolphthalein is used as the indicator.

[0024] A detector is used in this method to achieve automatic titration and automatic detection. The detector has a rotating tray 2 that can rotate under the drive of a motor. A plurality of reagent bottle slots 3 are provided on the rotating tray 2 for placing reagent bottles. Through holes are provided on two opposite sides of the reagent bottle slots 3, and a light source and a sensor are respectively located on both sides of the through holes on the reagent bottle slots. In this way, the light emitted by the light source illuminates the solution in the reagent bottle and is received by the sensor on the other side after transmission. The sensor transmits the color information of the detected light to the control system. Since multiple reagent bottle slots are provided, multiple reagent bottles can be placed at the same time, and the reagents in multiple reagent bottles can be detected at the same time.

[0025] The detector used in the present technical solution has a detection reagent dripping mechanism, through which the detection reagent is automatically dripped into the reagent bottle.

[0026] like Figure 1 As shown, the test reagent dripping mechanism primarily comprises a rotating arm 1, a filling pump, and a filling pipe. The rotating arm 1 is driven by a motor. A filling nozzle is located at the upper, outer end of the rotating arm. One end of the filling pipe extends from the instrument housing and connects to the reagent bottle. The other end of the filling pipe extends upward along the interior of the rotating arm and connects to the filling nozzle. When the reagent is needed, the rotating arm rotates to align the filling nozzle with the reagent bottle. Multiple test reagent dripping mechanisms can be provided.

[0027] During the process of adding the test reagent, it is usually necessary to stir the solution in the reagent bottle in order to make the added reagent and the solution to be tested react as quickly as possible. Preferably, magnetic stirring is used to stir the solution in the reagent bottle. A magnetic stirrer is set at the bottom of the reagent bottle tank, and a magnetic stirring bar is placed in the reagent bottle during operation.

[0028] The detector has an end cover. During the detection process, the end cover 4 is used to cover the rotating tray to reduce odor leakage and light-proof reaction of the peroxide value.

[0029] The method for detecting peroxide value or acid value of the present technical solution has the following working process: add the liquid to be tested into the reagent bottle and place a magnetic stirrer, extend the outer end of the filling pipe of the detection reagent dripping mechanism into the detection reagent bottle, and different filling pipes extend into different detection reagent bottles. Start the machine, and the detection reagent dripping mechanism drips the detection reagent into the reagent bottle. During this process, the light source continuously irradiates the reagent bottle, and the light passing through the reagent bottle is received by the sensor and transmitted to the control system; when the control system detects the color of the light received by the sensor and compares it with the preset color, it stops dripping the detection reagent; records the titration end point, and can determine the value of the parameter being tested, and determine the peroxide value or acid value of the reagent sample. During the detection process, the rotating tray drives the reagent bottle to rotate, and multiple reagents can be dripped and detected at the same time.

[0030] The present invention utilizes light to irradiate reagents and uses sensors for color detection, which can realize automatic detection of peroxide value and acid value, improve detection accuracy, perform automated detection for a long time, and improve detection efficiency; at the same time, it prevents workers from inhaling irritating odors and toxic and harmful gases.

[0031] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for detecting peroxide value and acid value of food, characterized in that: The sample to be tested is placed in a reagent bottle, and then the test reagent is added dropwise to the reagent bottle; during this process, a light source is used to illuminate the reagent bottle, and a sensor is used to receive light transmitted through the reagent in the reagent bottle; a control system detects the light received by the sensor; when the color of the received light is a preset value, the addition of the test reagent is stopped; the titration endpoint is recorded and the peroxide value is determined; the same method can be used to determine the acid value, but the solution color determined by the titration endpoint for determining the peroxide value is different.

2. A method for detecting peroxide value and acid value of food according to claim 1, characterized in that: The detector has a rotating tray; a plurality of reagent bottle slots are arranged on the rotating tray, and through holes for allowing light to pass are arranged on two opposite sides of the reagent bottle slots; a light source and a sensor are located on both sides of the through holes on the reagent bottle slots.

3. A method for detecting peroxide value and acid value of food according to claim 2, characterized in that: The reagents in multiple reagent bottles can be tested at the same time.

4. A method for detecting peroxide value and acid value of food according to any one of claims 1 to 3, characterized in that: Use a detector to perform testing; the detection reagent dripping mechanism of the detector automatically drips the detection reagent into the reagent bottle.

5. A method for detecting peroxide value and acid value of food according to any one of claims 1 to 3, characterized in that: During the process of adding the detection reagent, stir the solution in the reagent bottle.

6. A method for detecting peroxide value and acid value of food according to claim 5, characterized in that: Use magnetic stirring to stir the solution in the reagent bottle.

7. A method for detecting peroxide value and acid value of food according to any one of claims 1 to 3, characterized in that: The detection reagent dripping mechanism includes a rotating arm, a filling pump and a filling pipe; the rotating arm is driven to rotate by a motor; a filling nozzle is set at the end of the rotating arm; one end of the filling pipe extends from the instrument housing, and the other end extends along the inside of the rotating arm and is connected to the filling nozzle.

8. The automatic peroxide value detector according to claim 7, wherein: During use, the filling pipe extends from the instrument housing and is connected to the filling reagent bottle.

9. The automatic peroxide value detector according to claim 7, wherein: Several detection reagent dropping mechanisms are provided.

10. An automatic peroxide value detector according to any one of claims 7 or 8, characterized in that: The detection reagent dripping mechanism has a plurality of reagent filling nozzles.

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