阅读说明：本技术 用鲜辣椒果实表面颜色快速检测辣椒素类物质含量的方法 (Method for rapidly detecting content of capsaicin substances by using surface color of fresh pepper fruits ) 是由 高佳 田玉肖 宋占锋 朱永清 罗芳耀 罗静红 黄驰 王自鹏 李浦 于 2020-12-10 设计创作，主要内容包括：本发明属于食品加工技术领域,尤其涉及一种采用鲜辣椒果实表面颜色快速检测其辣椒素类物质含量的方法,包括准备待检样品、检测待测新鲜辣椒果实表面的色差值L*,a*和将步色差值L*,a*代入检测模型中,即得待测辣椒样品的整果辣椒素类物质含量。本发明中检测方法简单、快速、稳定和重复性好,有助于辣椒新品种筛选和辣椒商品等级的划分,保障辣椒产品质量和生产稳定性。(The invention belongs to the technical field of food processing, and particularly relates to a method for rapidly detecting the content of capsaicin substances on the surface of a fresh pepper fruit by adopting the surface color of the fresh pepper fruit. The detection method is simple, rapid, stable and good in repeatability, is beneficial to screening of new pepper varieties and classification of pepper commodity grades, and guarantees the quality and production stability of pepper products.)

1. A method for rapidly detecting the content of capsaicin substances by using the surface color of fresh pepper fruits is characterized by comprising the following steps: the method comprises the following steps:

(1) preparing a sample to be detected: selecting fresh pepper fruits as a sample to be detected;

(2) detecting the color difference value L, a of the surface of the fresh pepper fruit to be detected;

wherein the L values are the intensity coordinates in the CIE L a b color space system; a is the chromaticity coordinate of the red-green axis in the CIE L a b color space system;

(3) and (3) measuring the content of capsaicin: and (3) substituting the color difference value L, a in the step (2) into a detection model to obtain the content of the capsaicin of the whole fruit of the pepper sample to be detected, wherein the detection model is Y (capsaicin) -90.583+11.083 a-4.542L.

2. The method for rapidly detecting the content of the capsaicinoids in the surface color of the fresh pepper fruits as claimed in claim 1, wherein: the detection device in the step (2) is a color difference meter.

3. The method for rapidly detecting the content of the capsaicinoids in the surface color of the fresh pepper fruits as claimed in claim 2, wherein: when the detection device is used for measuring, the color difference value of 3 parts of each pepper on the surface is randomly measured, and the average value is taken.

4. The method for rapidly detecting the content of the capsaicinoids in the surface color of the fresh pepper fruits as claimed in claim 1, wherein: the test model was applied to test for color difference values L ranging from 34.49 to 44.41 and color difference values a ranging from 28.53 to 48.02.

5. The method for rapidly detecting the content of the capsaicinoids in the surface color of the fresh pepper fruits as claimed in claim 1, wherein: the sample to be detected is mature fresh pepper fruits which are uniformly colored.

6. The method for rapidly detecting the content of the capsaicinoids in the surface color of the fresh pepper fruits as claimed in claim 5, wherein: the fresh pepper fruits are red pod peppers.

7. The method for rapidly detecting the content of the capsaicinoids in the surface color of the fresh pepper fruits as claimed in claim 1, wherein: the measurement environment temperature is 0-40 ℃, and the environment humidity is less than or equal to 85%.

8. A method for establishing a model for rapidly detecting the content of capsaicin substances by using the surface color of fresh pepper fruits is characterized by comprising the following steps: the method comprises the following steps:

(1) selecting a fresh pepper fruit sample, and measuring the color difference values L and a;

(2) preparing pepper standard substance and reference substance solution, and measuring the content of capsaicin in the pepper standard substance and the reference substance solution by using a liquid chromatography system, namely the sum of capsaicin and dihydrocapsaicin;

(3) establishing a regression detection model: establishing a regression equation by using the color difference values L and a of the pepper and the content of capsaicin, wherein Y is-90.583 +11.083 a-4.542L;

(4) and measuring the color difference values L and a of the products, and substituting the color difference values L and a into a detection model to calculate to obtain the content of the capsaicin.

Technical Field

The invention belongs to the technical field of food processing, and particularly relates to a method for rapidly detecting the content of capsaicin substances by using the surface color of fresh pepper fruits.

Background

The pepper is an important worldwide vegetable and seasoning, and is popular with consumers. The flavor of the pepper product is mainly determined by comprehensive feelings such as taste (sugar, organic acid), smell (volatile esters, terpenes and the like), spicy pain (capsaicin substances) and the like. Among them, capsaicin is the main component for the perception of hot pepper and becomes one of the important indicators for evaluating the quality of hot pepper. Capsaicin and dihydrocapsaicin are main components constituting capsaicin substances, and account for about 90% of the total capsaicin substances, so the content of capsaicin and dihydrocapsaicin is often used for expressing the pungency degree of pepper. The current determination method for capsaicin requires a complicated process and is highly dependent on instruments. For example, the content of capsaicin is measured by using high performance liquid chromatography, ultraviolet spectrophotometry, gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry and near infrared spectrum analysis technologies, chemical analysis can be performed, and a certain effect is achieved. The gas chromatography-mass spectrometry and the liquid chromatography-mass spectrometry are high in detection sensitivity, but instruments are expensive, technical requirements on operators are high, maintenance is troublesome, and popularization and use are difficult. The near infrared spectrum analysis technology has the advantages of high analysis speed, no damage to samples, simple operation and good stability, but also has the problems of high price of special equipment, large modeling workload, high cost and the like.

Disclosure of Invention

In order to solve the technical problems, the invention provides a method for rapidly detecting the content of capsaicin substances by using the surface color of fresh pepper fruits, which is used for determining the content of the capsaicin substances by establishing a regression prediction model of the surface color difference values L, a of the mature peppers and the content of the capsaicin substances; the method is simple, rapid, accurate, stable and good in repeatability.

The method for rapidly detecting the content of capsaicin substances by using the surface color of fresh pepper fruits, which solves the technical problems, is characterized by comprising the following steps of: the method comprises the following steps:

(1) preparing a sample to be detected: selecting mature fresh pepper fruits with consistent colors as a sample to be detected;

(2) detecting the color difference value L, a of the surface of the fresh pepper fruit to be detected;

wherein the L values are the intensity coordinates in the CIE L a b color space system; a is the chromaticity coordinate of the red-green axis in the CIE L a b color space system;

(3) and (3) measuring the content of capsaicin substances: and (3) substituting the color difference value L, a in the step (2) into a detection model to obtain the average capsaicin substance content of the whole fruit of the pepper sample to be detected, wherein the detection model is Y (capsaicin substance content) — 90.583+11.083 a-4.542L.

In the step (2), the detection device is a color difference meter.

When the detection device is used for measuring, the color difference value of 3 parts of each pepper on the surface is randomly measured, and the average value is taken.

The measurement environment temperature is 0-40 ℃, the environment humidity is less than or equal to 85%, and the measurement stability and accuracy of the color colorimeter are guaranteed.

The detection model is applied to detecting the color difference value L in a range of 34.49-44.41, the color difference value a in a range of 28.53-48.02 and the content unit of capsaicin substances is mu g/g.

The sample to be detected is mature fresh pepper fruits which are uniformly colored.

The fresh pepper fruits are red pod peppers.

The invention relates to a method for establishing a model for rapidly detecting the content of capsaicin substances by adopting the surface color of fresh pepper fruits, which comprises the following steps:

(1) selecting red fresh pepper fruits with consistent maturity, and measuring the color difference values L and a;

(2) preparing a pepper standard substance and a reference substance solution, and measuring the content of capsaicin in the pepper standard substance and the reference substance solution by using a liquid chromatography system, namely the sum of capsaicin and dihydrocapsaicin;

wherein a standard curve is established for calculating the capsaicin and dihydrocapsaicin contents, using the stability of a liquid phase mass spectrometer.

(3) Establishing a regression detection model: establishing a regression equation by using the color difference values L and a of the pepper and the content of capsaicin, wherein Y (capsaicin) is-90.583 +11.083 a-4.542L;

(4) and measuring the color difference values L and a of the products, and substituting the color difference values L and a into a detection model to calculate to obtain the content of the capsaicin.

The method disclosed by the invention is used for detecting the capsaicin, so that the rapid nondestructive detection of the capsaicin in the fresh peppers is realized, the screening of new pepper varieties and the classification of pepper commodity grades are facilitated, and the pepper product quality and the production stability are ensured.

Detailed Description

The specific operation process is illustrated in detail by the specific examples, but the invention is not limited to the following examples: the process is conventional unless otherwise specified, and the starting materials are commercially available from the open literature:

the color difference detector was a CR-400 type color difference meter (KONICA, Japan), the weighing apparatus was an electronic balance model JA31002 (Shanghai Jingtian electronic instruments, Inc.), the liquid chromatography system was Agilent 1260 infinitiy (Agilent technologies, England, USA), and the test material (pod pepper) was obtained from the test base of the academy of agricultural sciences, Sichuan province.

The used test raw materials (fresh pepper fruits, pod pepper) are collected in the test base of agricultural academy of sciences of Sichuan province, and have uniform size, consistent maturity, no residue, disease or secondary fruits.

Example 1

A method for rapidly detecting the content of capsaicin substances in fresh pepper fruits by using the surface color of the fresh pepper fruits comprises the following steps:

(1) preparing a sample to be detected: selecting mature fresh pepper fruits with consistent colors as a sample to be detected;

(2) detecting the color difference value L, a of the surface of the fresh pepper fruit to be detected; the detection device is a color difference meter.

Measurement type: reflection measurement, measurement of caliber: 8mm, lighting caliber: 11mm, observation light source: d65 light source. Standard observer: 2 ° standard observer.

Wherein the L values are the intensity coordinates in the CIE L a b color space system; a is the chromaticity coordinate on the red-green axis in the CIE L a b color space system.

The measurement environment temperature is 0 or 40 ℃, and the environment humidity is less than or equal to 85 percent.

(3) And (3) measuring the content of capsaicin substances: and (3) substituting the color difference value L, a in the step (2) into a detection model to obtain the average capsaicin substance content of the whole fruit of the pepper sample to be detected, wherein the detection model is Y (capsaicin substance content) — 90.583+11.083 a-4.542L.

The test model was applied to test the range of the color difference L from 34.49 to 44.41 and the range of the color difference a from 28.53 to 48.02.

Example 2

The other steps are as in example 1, with the ambient temperature being measured at 25 ℃ and the ambient humidity being less than or equal to 85%. The color difference values L and a of the uniformly colored fresh peppers are measured by a color difference meter for each material, and the color difference values of 3 parts of each pepper are randomly measured on the surface of each pepper, and the average value is taken.

Example 3

A method for establishing a model for rapidly detecting the content of capsaicin substances by adopting the surface color of fresh pepper fruits comprises the following steps:

(1) selecting fresh pepper fruits, and measuring the color difference values L and a of the fresh pepper fruits;

(2) preparing a pepper standard substance and a reference substance, and measuring the content of capsaicin in the pepper standard substance and the content of a capsaicin reference substance by using a liquid chromatography system, namely the sum of capsaicin and dihydrocapsaicin;

(3) establishing a regression detection model: establishing a regression equation by using the color difference values L and a of the pepper and the content of capsaicin, wherein Y (capsaicin) is-90.583 +11.083 a-4.542L;

(4) and measuring the color difference values L and a of the products, and substituting the color difference values L and a into a detection model to calculate to obtain the content of the capsaicin. The specific operation steps are as follows:

determination of color difference value of pepper

The calibration set adopts 17 fresh peppers, and the prediction set adopts 50 fresh peppers which are randomly selected.

The color difference values L and a of the uniformly colored fresh peppers are measured by a color difference meter for each material, and the color difference values of 3 parts of each pepper are randomly measured on the surface of each pepper, and the average value is taken.

And (3) measuring the content of capsaicins:

detecting with liquid chromatography system, weighing 1g fresh sample powder (lyophilized after liquid nitrogen treatment) in a centrifuge tube, adding 6mL methanol, and performing ultrasonic extraction at 60 deg.C for 40 min. After cooling the sample, it was centrifuged at 8000rpm for 10min and the supernatant was filtered through a 0.45 μm organic filter into a chromatography flask. Detection conditions of the liquid chromatography system are as follows: a chromatographic column: zorbax SB-c 184.6 mm x 250mm, mobile phase: 70% methanol, flow rate: 0.8mL/min, ultraviolet detection wavelength: 280nm, column temperature: both ends are 30 ℃, sample injection amount: 10 μ L. The liquid chromatography system can respectively obtain the content of capsaicin and dihydrocapsaicin, and the content of capsaicin is the sum of capsaicin and dihydrocapsaicin.

Establishment of a standard curve:

preparing serial reference substance solutions with concentration (range of 0.5-200 μ g/ml, and 8 concentration gradients) from capsaicin and dihydrocapsaicin, determining according to the above capsaicin content determination conditions, respectively taking peak areas of capsaicin and dihydrocapsaicin as ordinate, respectively taking the concentration of the reference substance as abscissa, and drawing standard curves to obtain regression equations of capsaicin and dihydrocapsaicin respectively of y-7.4164 x +3.2496(R is²＝0.9999)、y＝6.0948x+1.2983(R²0.9999), the linear range is 0.5 mug/ml to 200 mug/ml, and the result shows that the capsaicin and the dihydrocapsaicin have good linear relation in the linear range.

Data analysis

The experimental data was processed using IBM SPSS Statistics 22 software.

In this example, the color difference values L, a and capsaicin contents of 17 pepper species were first determined, and the results are shown in table 1 below:

TABLE 1 color difference of pepper and capsaicin content table

Establishing a regression equation by using the color difference values L and a of the peppers and the content of capsaicin substances:

obtaining a model 1 by taking the capsaicin content of the hot pepper as a dependent variable and the color difference value a as an independent variable; the capsaicin content of the pepper is used as a dependent variable, the color difference values L and a are used as independent variables to obtain a model 2, and the regression analysis result is shown in tables 2 and 3.

TABLE 2 regression analysis of the color difference values L, a as independent variables and capsaicin content

TABLE 3 model regression coefficient Table

And (3) analyzing a regression result:

as can be seen from table 2, when the color difference value a is taken as an independent variable, the capsaicin content is 94.9% affected by the color difference value a; when the color difference values L, a are independent variables, the capsaicin content is affected by both the color difference value L and the color difference value a by 97.5%. The F values for model 1 and model 2 to verify the significance of the regression formulae are 277.312 and 271.582, respectively, and sig. are both 0.000 < 0.01, which is "very significant", indicating that the compositional regression formulae are both statistically very significant.

As shown in table 3, the regression equation of model 1 is that Y (capsaicin content) — 186.033+9.224a (color difference a), and the value of each regression coefficient P (Sig.) is extremely significant and less than 0.01; the model 2 regression equation is that Y (capsaicin content) — 90.583+11.083a (color difference a) — 4.542L (color difference L), and the value of each regression coefficient P (Sig.) is less than 0.01, which is extremely significant.

Method verification

In order to embody the accuracy and the stability of the method, 50 pod pepper varieties are randomly selected for verification, wherein the predicted value is determined according to the detection model in the method, and the actual measurement value is determined according to a liquid mass spectrometry system. The results are given in Table 4 below:

TABLE 450 prediction set samples and test results List

Establishing a regression model by using the predicted value and the actually measured content of the capsaicin, selecting a stepwise regression method, setting the predicted value of the content of the capsaicin as an X variable, detecting the measured content of the capsaicin by using a liquid chromatography system as a Y variable, establishing a regression equation of 4.656+0.981X (Y represents the content of the capsaicin detected by using the liquid chromatography system, and X represents the predicted value), and determining a coefficient (r) of the regression model²) 0.985(p < 0.0001), and the absolute value of the difference is at most 11.44 and at least 0.20. Therefore, the detection result of the predicted value is close to the standard value, the accuracy of the detection result is high, and the method can be used for predicting the content of capsaicinoids in pod pepper.

While the foregoing shows and describes the fundamental principles and principal features of the invention, together with the advantages thereof, the foregoing embodiments and description are illustrative only of the principles of the invention, and various changes and modifications can be made therein without departing from the spirit and scope of the invention, which will fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.