CN216816447U - Device for judging peroxide value of vegetable oil by optical method - Google Patents

Abstract

The utility model discloses a device for judging peroxide value of vegetable oil by using an optical method, which comprises a bracket base, wherein a panel is fixedly and vertically arranged on the bracket base, a semicircular guide rail with a downward opening is fixedly arranged on one side of the panel, a sliding block base is arranged on the semicircular guide rail in a sliding manner, a laser is fixedly arranged on the sliding block base, and a circular dial concentric with the semicircular guide rail is fixedly arranged on one side of the panel, which is provided with the semicircular guide rail; one side of the bracket base close to the semicircular guide rail is used for placing a liquid storage tank with an open top and transparency, the height of the liquid level in the liquid storage tank can be adjusted, and laser emitted by the laser can be refracted at the liquid level in the liquid storage tank after passing through the circle center of the circular dial. The method can visually measure the refractive index of the peanut oil, and further estimate the peroxide value of the peanut oil, thereby evaluating the rancidity reaction degree of the peanut oil.

Description

Device for judging the peroxide value of vegetable oil by optical method

technical field

The utility model relates to the technical field of vegetable oil peroxide value detection, in particular to a device for judging the vegetable oil peroxide value by using an optical method.

Background technique

In recent years, the development of science and technology in my country has advanced by leaps and bounds, the social production capacity has grown rapidly, and people's living standards have also been continuously improved. At the same time, the public is paying more and more attention to the quality of life, and the nutrition and health of food in daily life has become a hot issue in today's society. Edible vegetable oil is an important part of the daily diet of the Chinese people, and its safety and conditions for safe use have attracted much attention. Peanut oil is the main oil produced in my country. It is light yellow and transparent in color, bright in color, fragrant in smell and delicious in taste. It is one of the edible vegetable oils widely used on the table of Chinese people.

On the other hand, the quality of peanut oil is greatly affected by environmental factors. Storage at higher temperatures or exposure to humid air for a long time will cause the peanut oil to undergo a rancidity reaction, destroy essential fatty acids and fat-soluble vitamins in the oil, and produce adverse effects on the peanut oil. Harmful aldehydes, ketones and other lipid peroxides. Long-term consumption of peanut oil of poor quality will lead to the occurrence of various diseases, and even cause cancer in severe cases. In family life, people often fail to seal the remaining peanut oil in time after use, or place the container containing the peanut oil near the high-temperature stove in operation due to the convenience of use. These practices will reduce the quality of peanut oil, or even deteriorate. If people can't detect the deterioration of peanut oil in time, it will have adverse effects on health after use.

When evaluating the degree of deterioration of peanut oil in the family, it mainly depends on the subjective judgment of people. One way is to smell the oil, and if the peanut oil develops an unpleasant jarring smell, it can be judged as spoiled. This method is effective when the peanut oil has obvious peculiar smell. When the peanut oil has deteriorated to a certain extent but the smell is not strong, it cannot be clearly identified. Another method is to observe whether there is sediment in the peanut oil container. If there is sediment in the oil, judge It has deteriorated. Due to the existence of various components in peanut oil, harmless insolubles will be precipitated under low temperature conditions, and the difference from the sediment is not obvious, so the method of observing the sediment is not accurate enough. If you need to accurately understand the quality of peanut oil, you can entrust a professional organization to conduct testing. In the process, chemical reagents such as sodium thiosulfate are usually used. Such professional testing methods are not suitable for families. Therefore, how to assess the deterioration degree of peanut oil at home has become an urgent problem to be solved.

The peroxide value of peanut oil can effectively reflect the degree of its rancidity reaction. The relationship between the peroxidation value and the heating temperature of peanut oil has been discussed in the literature. Through the refractive index experiment, the relationship between the refractive index and temperature of peanut oil can be obtained. The relationship between the refractive index and the peroxide value of peanut oil can be obtained by combining the two. To determine the degree of deterioration of peanut oil, there is an urgent need for a device and method that can directly measure the refractive index of peanut oil.

Utility model content

The purpose of this utility model is to provide a device for judging the peroxidation value of vegetable oil using an optical method, to solve the problems existing in the above-mentioned prior art, to intuitively measure the refractive index of peanut oil, and then to estimate its peroxidation value, thereby evaluating the Degree of rancidity reaction.

For achieving the above object, the utility model provides the following scheme:

The utility model provides a device for judging the peroxide value of vegetable oil by using an optical method. A slider base is slidably arranged on the semi-circular guide rail, a laser is fixedly arranged on the slider base, and a circular dial concentric with the semi-circular guide rail is fixedly arranged on one side of the panel provided with the semi-circular guide rail; The side of the bracket base close to the semi-circular guide rail is used to place a transparent liquid storage tank with an open top. The liquid level in the liquid storage tank can be adjusted. The laser emitted by the laser passes through the center of the circular dial. Refraction can occur at the liquid level in the liquid reservoir.

Optionally, two ends of the support base are symmetrically provided with support corners, and both ends of the panel are fixedly clamped in the support corners.

Optionally, the upper end of the slider base is provided with a laser installation hole, the laser is inserted in the laser installation hole, and one end of the slider base is inserted with a laser fixing block, and the laser fixing block can pass through. One end of the slider base is in fixed contact with the side wall of the laser located in the laser installation hole.

Optionally, a movable handle is installed on the top of the slider base, and a limit screw is movably inserted on one side of the bottom of the slider base, and the limit screw can pass through one side of the slider base and be connected to the other side. One side of the semicircular guide rail is fixedly abutted.

Optionally, the range of the dial is 360°, and the minimum graduation value is 0.5°; the top and bottom of the dial in the vertical direction are marked as 0°, and the horizontal positions on the left and right sides of the dial in the horizontal direction are marked as 90°.

Optionally, the liquid storage tank is a cube structure made of a plexiglass plate, the external dimensions of the liquid storage tank are 6cm×2cm×11cm, and the thickness of the plexiglass plate is 1mm; the upper edge of the liquid storage tank is high The lower end of the liquid storage tank is sealed and connected with a syringe through a plastic hose and a control valve, and the syringe is fixedly installed on the side of the panel away from the semicircular guide rail.

Optionally, the laser is an in-line laser, the linear laser emitted by the in-line laser is in-line, and the light width and power can be adjusted.

The utility model also provides a method for judging the peroxide value of vegetable oil by using an optical method, comprising the following steps:

Step 1: Fix the laser on the slider base, adjust the laser beam width and emission power to an appropriate value, and no longer adjust the laser during the subsequent experiments;

Step 2: Pour the peanut oil into the liquid storage tank, place the liquid storage tank on the side of the bracket base close to the semicircular guide rail, and adjust the peanut oil liquid level so that the peanut oil liquid level coincides with the horizontal 90° scale line of the dial, and adjust the slider. The position of the block base on the semicircular guide rail, so that it can be fixed at a selected angle;

Step 3, turn on the laser, directly read the angle α _{1 between the incident beam and the 0° scribe line above, and record the angle β 1 between} the refracted beam and the 0° scribe line below;

Step 4: Turn off the laser to ensure that the liquid level in the experimental container does not move, adjust the position of the slider base on the semicircular guide rail, repeat Step 3 9 times, and record the measured data each time;

Step 5. Use the formula

where n is the refractive index.

Calculate and record the refractive indices n ₁ to n ₁₀ measured 10 times, and then calculate the average n of the above 10 refractive indices;

Step six, use the formula

v=-48.29n+77.80,

Among them, 1.3789≤n≤1.4365

Calculate the peroxide value v of peanut oil, and then evaluate the degree of rancidity reaction of peanut oil.

The utility model has achieved the following technical effects with respect to the prior art:

The utility model proposes a brand-new method that can quickly determine the peroxide value of peanut oil through physical properties, can relatively quickly judge the degree of deterioration of the peanut oil, can help people quickly understand the situation of the peanut oil at home, and has high application value. The utility model builds a bridge between the physical judgment method and the chemical judgment method through a rigorous logical chain, links the two methods together, and has great research significance. The utility model designs a new device for measuring the refractive index of liquid, which has the advantages of high speed and high accuracy, and is convenient and concise, easy to operate, and convenient for common people to use. Using this device, the refractive index of the liquid to be measured can be measured efficiently. The utility model adopts a brand-new method to estimate the deterioration of peanut oil, provides a brand-new means for the quality detection of vegetable oil, and makes a certain contribution to the further improvement of food safety.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only of the present invention. For some embodiments of the present invention, for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

Fig. 1 is the device structure schematic diagram that the utility model utilizes optical method to judge the peroxidation value of vegetable oil;

Fig. 2 is a partial enlarged view in Fig. 1;

Fig. 3 is the utility model dial schematic diagram;

Among them, 1 is the panel, 2 is the dial, 3 is the semicircular guide rail, 4 is the slider base, 5 is the laser fixing block, 6 is the movable handle, 7 is the bracket base, 8 is the bracket support angle, 9 is the limit Screw, 10 is a laser, 11 is a liquid storage tank, and 12 is an infusion tube.

Detailed ways

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the implementations. example. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

The purpose of this utility model is to provide a device for judging the peroxidation value of vegetable oil using an optical method, to solve the problems existing in the above-mentioned prior art, to intuitively measure the refractive index of peanut oil, and then to estimate its peroxidation value, thereby evaluating the Degree of rancidity reaction.

In order to make the above objects, features and advantages of the present utility model more clearly understood, the present utility model will be described in further detail below with reference to the accompanying drawings and specific embodiments.

The peroxide value of peanut oil can effectively reflect the degree of its rancidity reaction. At present, the relationship between the peroxide value of peanut oil and the heating temperature has been discussed in the literature. The authors found through the absorption spectrum experiments of peanut oil under different heating conditions that the physical properties of peanut oil changed significantly under different heating conditions. Through the refractive index experiment, the relationship between the refractive index of peanut oil and temperature is known. The method proposed by the utility model is to measure the refractive index of peanut oil, convert the refractive index into the highest heating temperature experienced by the peanut oil, and then convert the heating temperature into peroxide value to establish a direct relationship between the refractive index and the peroxide value. Using this method, measuring the refractive index of peanut oil, can estimate its peroxide value, based on this, the utility model provides a device for judging the peroxide value of vegetable oil using an optical method, as shown in Figure 1, Figure 2 and Figure 3, It includes a support base 7 and a panel 1. The two ends of the support base 7 are symmetrically provided with support corners 8. The two ends of the panel 1 are fixedly clamped in the support corners 8. One side of the panel 1 is fixedly provided with a semicircular guide rail 3 with an opening downward. A slider base 4 is slidably arranged on the semicircular guide rail 3, and a laser 10 is fixed on the slider base 4. The laser 10 is an in-line laser, and the linear laser emitted by the in-line laser is in a in-line shape, and the light width is from 0.4mm to several. The centimeter is adjustable, and the power is adjustable from 0-20mw. The side of the panel 1 with the semi-circular guide rail 3 is fixedly provided with a circular dial 2 that is concentric with the semi-circular guide rail 3; the side of the bracket base 7 close to the semi-circular guide rail 3 is used for A liquid storage tank 11 with an open top and a transparent top is placed. The height of the liquid level in the liquid storage tank 11 can be adjusted. The laser emitted by the laser 10 can be refracted on the liquid level in the liquid storage tank after passing through the center of the circular dial 2 .

Further preferably, the upper end of the slider base 4 is provided with a laser installation hole, the laser is inserted in the laser installation hole, and one end of the slider base 4 is inserted with a laser fixing block 5, and the laser fixing block 5 can pass through one end of the slider base 4. It is fixedly abutted with the side wall of the laser located in the laser mounting hole. A movable handle 6 is installed on the top of the slider base 4 to facilitate manual adjustment of the position of the slider. A limit screw 9 is movably inserted on one side of the bottom 4 of the slider base, and the limit screw 9 can pass through the slider base 4-1. The side rear is in fixed contact with the side of the semicircular guide rail 3 . The range of the dial 2 is 360°, and the minimum division value is 0.5°; the upper and lower parts of the vertical direction of the dial 2 are marked as 0°, and the horizontal position of the left and right sides of the dial 2 in the horizontal direction is marked as 90°. The liquid storage tank 11 is a cubic structure made of a plexiglass plate, the external dimensions of the liquid storage tank 11 are 6cm×2cm×11cm, and the thickness of the plexiglass plate is 1mm; the upper edge of the liquid storage tank 11 is higher than the 90° horizontal scribe line; A syringe is sealingly connected to the lower end of the liquid storage tank 11 through the infusion tube 12 and the control valve, and the syringe is fixedly installed on the side of the panel away from the semicircular guide rail.

The utility model also provides a method for judging the peroxide value of vegetable oil by using an optical method, and the specific process is as follows:

The relationship between the peroxide value of peanut oil and the heating temperature has many parameters to characterize the quality of peanut oil. The peroxide value parameter indicates the degree of oxidation of oil and unsaturated fatty acids, which can be used to indicate whether the sample has deteriorated due to oxidation. Changes in components such as oils and fatty acids in peanut oil will cause changes in the refractive index of the oil, so it can be detected by optical methods.

Li Xinhua and others published a paper in "Food Industry", revealing the changes in the peroxide value of peanut oil after being heated at a constant temperature of 60°, 70°, 80°, 90°, and 100° for 15 minutes. The shape of the broken line of the original data is close to linear, so a linear regression analysis is performed on the peroxide value and temperature. get the regression line,

是过氧化值的估计值，T是加热温度(单位：摄氏度)in

is the estimated value of peroxide value, T is the heating temperature (unit: degrees Celsius)

Based on this, the present utility model firstly explores the relationship between the refractive index of peanut oil and the heating temperature. During the experiment, the liquid level of the peanut oil is adjusted to coincide with the horizontal scale line of the dial (the left and right sides of the dial are marked as 90°); The laser is installed on the slider seat on the slide rail, and the output linear laser points from the slide rail to the center of the dial, and refracts on the horizontal peanut oil surface, the refracted beam enters the peanut oil, and observes the relationship between the linear laser and the dial in the air. Coincidence lines, read the incident angle in the air, observe the coincident line of the linear laser in the peanut oil and the dial, and read the refraction angle in the peanut oil; change the position of the slider on the slide rail to adjust the incident angle of the laser. All calibration and readings are done here.

Prepare 5 parts of peanut oil of equal quality, heat it to 60°C, 70°C, 80°C, 90°C, and 100°C in turn using a constant temperature water bath heating pot, and keep it at this temperature for 15 minutes. After the heating was completed, the peanut oil was allowed to stand for about 8 hours to cool, and a refractive index tester was assembled at the same time to adjust the laser beam width and emission power to appropriate values. The laser was not adjusted during the subsequent experiments.

After the oil heated to 60°C has cooled to room temperature, it is poured into a thin plexiglass container. Pull the syringe to make the oil level in the container coincide with the horizontal 90° scale line, close the valve, and adjust the position of the slider on the slide rail to make it fixed at a selected angle.

Turn on the laser, directly read the angle α _{1 between the incident beam and the 0° scribe line above, and record the angle β 1 between} the refracted beam and the 0° scribe line below.

Turn off the laser to ensure that the liquid level in the experimental container does not move, adjust the position of the slider base on the semicircular guide rail, repeat the above process 9 times, and record the data measured each time separately;

Step 5. Use the formula

Calculate and record the refractive indices n ₁ to n ₁₀ measured 10 times, and then calculate the average n of the above 10 refractive indices;

Step six, use the formula

v=-48.29n+77.80,

Among them, 1.3789≤n≤1.4365

Calculate the peroxide value v of peanut oil heated to 60°C.

Unplug the connecting hose from the syringe port and pour the oil back into the cup. After carefully cleaning the two containers, replace the oil heated to a different temperature, repeat the above process, and record the measured experimental data in the table.

Heating at a constant temperature of 60°C for 15min, after cooling, the average refractive index of peanut oil was determined to be 1.4365, heated at a constant temperature of 70°C for 15min, and the average refractive index of peanut oil was determined to be 1.4266 after cooling, and heated at a constant temperature of 80°C for 15min, and the peanut oil was measured after cooling. The average refractive index of the peanut oil was 1.4158, and the average refractive index of the peanut oil was 1.3989 after being heated at 90 °C for 15 minutes. After cooling, the average refractive index of the peanut oil was 1.3989. The average refractive index of the peanut oil was 1.3789 after cooling at a constant temperature of 100 °C. The relationship between the refractive index of peanut oil and the heating temperature was obtained.

Because the shape of the broken line of the above data is close to linear, a linear regression analysis is performed on the refractive index and temperature in this paper. get the regression line

是折射率的估计值，T是加热温度。of which is

is an estimate of the refractive index and T is the heating temperature.

Estimating the peroxide value of peanut oil, the utility model above expresses the estimated formula (1) of the peroxide value and temperature of peanut oil,

V=V(T)=6.900×10 ^-2 T+4.316, 60℃≤T≤100℃,

Equation (2) for the estimation of the refractive index and temperature of peanut oil,

n=n(T)=-1.429×10 ^-3 T+1.526, 60℃≤T≤100℃.

Because the primary function has an inverse function, so n(T) has an inverse function, and its inverse function is

T=T(n)=-699.79n+1067.88, 1.3789≤n≤1.4365,

Combining T(n) and V(T), we get

V=V(n)=V(T(n))=-48.29n+77.80, 1.3789≤n≤1.4365,

So far, the estimation formulas of peroxide value and refractive index have been obtained in this paper.

V=-48.29n+77.80, 1.3789≤n≤1.4365. (3)

To sum up, when the refractive index of peanut oil is known, and the refractive index is between to, the peroxide value of peanut oil can be calculated by formula (3), and then the degree of rancidity reaction of peanut oil can be evaluated. By consulting the "National Standard for Peanut Oil Quality", when the peroxide value of peanut oil reaches 9.375meq/kg, that is, when the refractive index of the oil body is less than 1.417, it exceeds the edible range. This method builds a bridge between the physical property of refractive index and the chemical property of oxidation value, and is a brand-new judgment method.

In the description of the present invention, it should be noted that the terms "center", "top", "bottom", "left", "right", "vertical", "horizontal", "inner" and "outer" The orientation or positional relationship indicated by etc. is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, with a specific orientation. Therefore, it should not be construed as a limitation on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

Specific examples are used in the present invention to illustrate the principles and implementations of the present invention. The descriptions of the above embodiments are only used to help understand the methods and core ideas of the present invention; at the same time, for those skilled in the art , according to the idea of the present utility model, there will be changes in the specific implementation and application scope. In conclusion, the content of this specification should not be construed as a limitation on the present invention.

Claims (7)

1. the device that uses optical method to judge the peroxidation value of vegetable oil, it is characterized in that: comprise support base, described support base is fixed and vertically provided with panel, one side of described panel is fixedly provided with the semicircular guide rail with opening downward, described A slider base is slidably arranged on the semi-circular guide rail, a laser is fixedly arranged on the slider base, and a circular dial concentric with the semi-circular guide rail is fixedly arranged on one side of the panel provided with the semi-circular guide rail; The side of the bracket base close to the semi-circular guide rail is used to place a transparent liquid storage tank with an open top. The liquid level in the liquid storage tank can be adjusted. The laser emitted by the laser passes through the center of the circular dial. Refraction can occur at the liquid level in the liquid reservoir. 2. The device for judging the peroxidation value of vegetable oil using an optical method according to claim 1, wherein the two ends of the support base are symmetrically provided with support angles, and the two ends of the panel are fixedly clamped to the support supports. inside the corner. 3. The device for judging the peroxide value of vegetable oil using an optical method according to claim 1, wherein the upper end of the slider base is provided with a laser mounting hole, and the laser is inserted in the laser mounting hole, so that the A laser fixing block is inserted at one end of the slider base, and the laser fixing block can pass through one end of the slider base and then fixedly abut with the side wall of the laser located in the laser installation hole. 4. The device for judging the peroxide value of vegetable oil using an optical method according to claim 3, characterized in that: a movable handle is installed on the top of the slider base, and a limiter is movably inserted on one side of the bottom of the slider base. A screw, the limit screw can pass through one side of the slider base and then be in fixed contact with one side of the semicircular guide rail. 5. the device that utilizes optical method to judge the peroxidation value of vegetable oil according to claim 1, is characterized in that: the range of described dial is 360 °, and the minimum graduation value is 0.5 °; The lower part is marked as 0°, and the horizontal position of the left and right sides of the dial in the horizontal direction is marked as 90°. 6. the device that utilizes optical method to judge the peroxidation value of vegetable oil according to claim 5, is characterized in that: described liquid storage tank is the cubic structure that adopts plexiglass plate to make, and described liquid storage tank external dimension specification is 6cm ×2cm×11cm, the thickness of the plexiglass plate is 1mm; the upper edge of the liquid storage tank is higher than the 90° horizontal scribe line; the lower end of the liquid storage tank is sealed with a syringe through a plastic hose and a control valve, and the syringe is fixedly installed on the side of the panel away from the semicircular guide rail. 7. the device that utilizes optical method to judge the peroxidation value of vegetable oil according to claim 1, is characterized in that: described laser is in-line laser, the linear laser that described in-line laser emits is in-line, light width and Power can be adjusted.

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