Rice taste score calculation method based on multiple sensor arrays

Abstract

The invention belongs to the field of food analysis, and particularly relates to a rice taste score calculation method based on multiple sensor arrays. The method comprises the following steps: 1) measuring rice soup prepared from rice samples through a volt-ampere measurement method, wherein each sample obtains original volt-ampere signals of three metal working electrodes; 2) measuring rice made of rice samples by a gas response method, wherein each sample obtains response signals of four types of gas sensors; and 3) correspondingly processing the original volt-ampere signal and the gas response signal, and calculating to obtain the taste score value of the rice sample. The taste score value of the rice sample is calculated by using the sensing amplitude vector, so that the rapid calculation of the taste score value of the rice is realized, and the working efficiency is greatly improved.

Description

Technical Field

[0001] The present invention belongs to the field of food analysis, and in particular relates to a method for calculating rice taste score values ​​based on multiple sensor arrays. Background Art

[0002] Rice is a staple food crop, and its taste quality has become a key concern for consumers. However, rice taste quality is still primarily determined by manual sensory evaluation by expert panels. Manual sensory evaluation is the most intuitive method, but it is susceptible to the psychological and physiological influences of individual tasters and is labor-intensive, material-intensive, and financially intensive. Therefore, it often fails to meet the demand for rapid evaluation of rice taste quality during the rice distribution process. The rice industry has long sought a method for rapidly evaluating rice taste using intelligent sensory instruments, replacing manual sensory evaluation.

[0003] In recent years, intelligent sensory instruments such as electronic tongues and electronic noses have emerged both domestically and internationally. These instruments typically utilize electrochemical sensor arrays to simulate artificial taste and smell, enabling the identification and classification of rice types, origins, and even rice plants. Intelligent sensory technology has shown promising application potential in rice type identification, origin traceability, and quality analysis. However, this technology also has its limitations. For example, the results of near-infrared-based taste meters often differ significantly from those of manual sensory evaluation. Researchers have commonly applied pattern recognition methods such as principal component analysis and discriminant analysis to intelligent sensory technology. However, these pattern recognition methods are not directly applicable to the rapid evaluation of rice flavor attributes. Therefore, a simple and effective method is needed to quickly obtain rice flavor scores.

[0004] The inventor's earlier invention, CN110297036B, titled "Method for Estimating the Taste of Indica Rice Based on a Sensor Matrix," describes a method using a sensor matrix to measure indica rice samples through electrochemical measurements. Working electrodes made of metals such as gold, nickel, palladium, platinum, titanium, and tungsten are used to obtain inflection point values ​​at different frequencies, construct a two-dimensional sensor matrix, and calculate the estimated taste of the indica rice.

[0005] However, this method still has some shortcomings, such as the metal working electrode is not combined with the gas sensor. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method for simply calculating the rice taste score.

[0007] In order to solve the above technical problems, the present invention provides a method for calculating rice taste score based on multiple sensor arrays, comprising the following steps: 1) The rice water prepared from rice samples was measured by voltammetry, and the original voltammetric signals of three metal working electrodes were obtained for each sample; 2) The rice made from rice samples was measured using the gas response method (gas sensor response method), and the response signals of four types of gas sensors were obtained for each sample; 3) Process the original voltammetric signal and gas response signal accordingly to calculate the taste score of the rice sample.

[0008] As an improvement to the method for calculating rice taste score based on multiple sensor arrays of the present invention, the three metal working electrodes are tungsten (W), titanium (Ti), and silver (Ag).

[0009] As a further improvement of the rice taste score calculation method based on multiple sensor arrays of the present invention: Tungsten (W), titanium (Ti), and silver (Ag) electrodes were used as working electrodes; a saturated Ag / AgCl electrode (the KCl concentration in the reference electrode chamber was saturated) was used as the reference electrode, and a platinum wire electrode was used as the auxiliary electrode. The voltammetric measurement frequency was 1 Hz, and the potential range was -1 V to 1 V. The corresponding measurement parameters were an excitation voltage of 1 V, a detection sensitivity of e-5, and a potential step of 0.2 V. Prepare rice soup by taking 10 g of rice, adding 50 mL of distilled water, and boiling for 15 ± 1 min to obtain a rice soup solution.

[0010] As a further improvement of the rice taste score calculation method based on multiple sensor arrays of the present invention: When measuring the sample using the voltammetry method, the W, Ti, and Ag electrodes were immersed in rice soup at the same time to obtain the original voltammetry signals of the three electrodes.

[0011] As a further improvement to the method for calculating rice taste score based on multiple sensor arrays of the present invention, step 2) is: The sensor on the electronic nose is used for detection, and the ratio of the conductivity response of the sample to the conductivity response of the ambient air is used as the response value.

[0012] As a further improvement to the method for calculating rice taste score based on multiple sensor arrays of the present invention, the measurement time of step 2) is set to 120 s.

[0013] As a further improvement to the rice taste score calculation method based on multiple sensor arrays of the present invention, step 3) is: The original voltammetric signal and gas response signal are decomposed by wavelet packet to obtain detail signal, and the detail signal is transformed by fast Fourier transform to obtain amplitude curve; Each metal working electrode and gas sensor obtains its own amplitude curve, and each amplitude curve has a maximum amplitude peak; therefore, each sample has 7 highest amplitudes, which are arranged into a sensing amplitude vector, and then the taste score of the rice sample is calculated.

[0014] As a further improvement to the rice taste score calculation method based on multiple sensor arrays of the present invention, the highest amplitudes FZ of three electrodes (W, Ti, Ag) and four gas sensors (2#, 5#, 7#, 8#) are extracted and arranged into a sensor amplitude vector: ; The sensor amplitude vector is used to calculate the taste score ESc of the rice sample. The formula is as follows: .

[0015] Compared with the prior art, the technical advantages of the present invention are: 1. The present invention establishes sensor amplitude vectors of multiple sensor arrays for rice, which is multivariate data that can represent the taste of rice and can be used to quickly calculate the taste score of rice; 2. This method uses sensor amplitude vectors to calculate the taste score of rice samples, enabling rapid calculation of the rice taste score. This greatly improves work efficiency and far exceeds the efficiency of manual evaluation. The results of this method are not significantly different from those obtained by manual evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the method of the present invention. DETAILED DESCRIPTION

[0017] The present invention will be further described below with reference to specific embodiments, but the protection scope of the present invention is not limited thereto.

[0018] Example 1: A method for calculating rice taste scores based on multiple sensor arrays. Rice soup prepared from rice samples was measured using voltammetry. Raw voltammetric signals were obtained for each sample from three metal working electrodes: tungsten (W), titanium (Ti), and silver (Ag). Simultaneously, cooked rice prepared from the rice samples was measured using a gas response method. Response signals from four gas sensors, 2#, 5#, 7#, and 8#, were obtained for each sample. The raw voltammetric and gas response signals were decomposed using wavelet packets to obtain detail signals, which were then subjected to fast Fourier transform to obtain amplitude curves. Each metal working electrode and gas sensor generated its own amplitude curve, each with a peak amplitude. Consequently, each sample had seven peak amplitudes, which were arranged into a sensor amplitude vector to calculate the rice sample's taste score.

[0019] The specific working methods include the following: 1) The three-electrode voltammetry method was used to measure each type of rice: In this example, tungsten (W), titanium (Ti), and silver (Ag) electrodes were used as working electrodes; a saturated Ag / AgCl electrode (the KCl concentration in the reference electrode chamber was saturated) was used as the reference electrode, and a platinum wire electrode was used as the auxiliary electrode. The voltammetric measurement frequency was 1 Hz, and the potential range was -1 V to 1 V. The corresponding measurement parameters were an excitation voltage of 1 V, a detection sensitivity of e-5, and a potential step of 0.2 V.

[0020] Rice samples were prepared into rice soup: 10 g of rice was added to 50 mL of distilled water and boiled for 15 min to obtain the rice soup solution.

[0021] When measuring the sample using the voltammetry method, the W, Ti, and Ag electrodes were immersed in rice soup at the same time to obtain the original voltammetry signals of the three electrodes.

[0022] 2) Use the gas sensor response method to measure each type of rice: The electronic nose has its own sensor. The sensor's response value is the ratio of the conductivity of the sample gas to the ambient air, and a corresponding response value curve is generated. For example, the present invention can use the SmartNose electronic nose of Zhejiang Zheke Instrument Equipment Co., Ltd., which has 1# to 10# gas sensors.

[0023] In this example, four gas sensors, 2#, 5#, 7#, and 8#, were used. The response value was the ratio of the conductivity response of the sample to the conductivity response of the ambient air. The measurement time was set to 120 s.

[0024] When measuring the sample using the gas response method, the 2#, 5#, 7#, and 8# gas sensors are placed directly above the rice (at a distance of 1-2 cm) to obtain the gas response signals of the four gas sensors.

[0025] 3) The original voltammetric signal of the rice sample obtained in step 1) and the gas response signal obtained in step 2) are decomposed into detail signals through wavelet packets. The detail signals are then transformed into amplitude curves through fast Fourier transform. The highest amplitudes FZ of the three electrodes (W, Ti, Ag) and four gas sensors (2#, 5#, 7#, 8#) are extracted and arranged into sensor amplitude vectors: ; Explanation: As is common sense, wavelet packet decomposition of the original signal yields an approximate signal and a detail signal. The detail signal amplifies subtle features within the original signal. The detail signal undergoes a fast Fourier transform (FFT), converting the signal data into complex form. The modulus of the complex number is used to represent the amplitude, yielding a Fourier transform curve (also called an amplitude curve). Each of the three electrodes and four gas sensors has its own amplitude curve. The highest amplitude value is taken from each, yielding seven peak amplitudes.

[0026] 4) The sensor amplitude vector obtained in step 3) is used to calculate the taste score ESc of the rice sample. The formula is as follows: .

[0027] Experiment 1: Calculate the taste score of 10 different rice samples; Ten different rice samples were numbered sequentially from S1 to S10, and each sample was sequentially subjected to steps 1) to 4) of Example 1 to obtain a taste score.

[0028] Taking the S1 rice sample as an example, the sensing amplitude vector is ; The calculated value is ESc= 70 (rounded to the integer).

[0029] The details are shown in Table 1 below.

[0030] Table 1 Maximum amplitude and taste score of 10 rice samples

[0031] Ten rice samples were scored by panelists according to the national standard GB / T15682-2008, "Testing of Cereals and Oils—Sensory Evaluation of Paddy and Steamed Rice." The manual evaluation scores for each rice sample are presented in Table 2. These scores are the average (rounded to an integer) of all panelists' evaluations of that rice sample. Table 2 shows a comparison of the manual evaluation scores for each rice sample with the corresponding taste scores.

[0032] Table 2 Manual evaluation scores and taste scores of 10 rice samples

[0033] As shown in Table 2, the relative differences between the taste scores of the 10 different rice samples and the manual evaluation scores were all less than 5%, confirming that the results obtained by this technique are generally consistent with those obtained by the national standard manual evaluation method. Therefore, the results of this method are valid and accurate.

[0034] In Comparative Example 1-1 and Example 1, only two types of electrodes (W, Ag) and four types of gas sensors (2#, 5#, 7#, 8#) are used to form the sensing amplitude vector, and the rest are the same as Example 1.

[0035] In Comparative Example 1-2 and Example 1, only three types of electrodes (W, Ti, Ag) and three types of gas sensors (2#, 7#, 8#) are used to form the sensing amplitude vector, and the rest are the same as Example 1.

[0036] Comparative Example 2-1: The three metal electrodes of "tungsten (W), titanium (Ti), and silver (Ag)" in Example 1 are replaced with three metal electrodes of "tungsten (W), platinum (Pt), and silver (Ag)". FZ Ti Replace with FZ Pt Substitute into the formula, and the rest is the same as in Example 1.

[0037] Comparative Example 2-2: The four gas sensors "2#, 5#, 7#, 8#" in step 1) of Example 1 are replaced with four gas sensors "2#, 3#, 7#, 8#". FZ 3# replace FZ 5# Substitute into the formula, and the rest is the same as in Example 1.

[0038] Three rice samples with low, medium and high taste quality (sample numbers S1, S5, and S10) were selected and tested using the methods described in Comparative Example 1-1, Comparative Example 1-2, Comparative Example 2-1, and Comparative Example 2-2, respectively. The resulting taste scores are listed in Table 3, Table 4, Table 5, and Table 6, respectively, and compared with the corresponding manual evaluation scores.

[0039] Table 3 Comparative Example 1-1 Manual evaluation scores and taste scores of low, medium and high rice

[0040] Table 4. Manual evaluation scores and taste scores of low, medium and high rice in comparative example 1-2

[0041] Table 5 Human taste evaluation scores and taste evaluation scores of low, medium and high rice in comparative example 2-1

[0042] Table 6 Comparative Example 2-2 Manual evaluation scores and taste scores of low, medium and high rice

[0043] As shown in Tables 3, 4, 5, and 6, the relative differences between the taste scores of the rice samples in the comparative example and the manual evaluation scores are all greater than 5%, indicating a significant deviation between the results obtained in the comparative example and those obtained using the national standard manual evaluation method. This demonstrates that the sensor amplitude vector used in this method is effective and can be used to quickly calculate accurate taste scores.

[0044] The present invention measures each type of rice by using a voltammetric measurement method and a gas response method, effectively avoiding the deviation caused by subjective evaluation by tasters, and has simple and convenient operation, low labor costs, and improved work efficiency of rice taste evaluation.

[0045] Finally, it should be noted that the above examples are merely specific embodiments of the present invention. Obviously, the present invention is not limited to the above examples and is subject to numerous variations. All variations that can be directly derived or conceived by a person of ordinary skill in the art from the disclosure of the present invention are considered to be within the scope of protection of the present invention.

Claims

1. A rice taste score calculation method based on multiple sensor arrays, characterized in that The following steps are involved: 1) The rice water prepared from rice samples was measured by voltammetry, and the original voltammetric signals of three metal working electrodes were obtained for each sample; 2) The rice samples were measured using the gas response method, and the response signals of the four types of gas sensors were obtained for each sample; 3) Process the original voltammetric signal and gas response signal accordingly to calculate the taste score of the rice sample.

2. The method for calculating rice taste score based on multiple sensor arrays according to claim 1, wherein: The three metal working electrodes are W, Ti, and Ag.

3. The method for calculating rice taste score based on multiple sensor arrays according to claim 2, wherein: W, Ti, and Ag electrodes were used as working electrodes; a saturated Ag / AgCl electrode was used as the reference electrode, and a platinum wire electrode was used as the auxiliary electrode. The voltammetric measurement frequency was 1 Hz, and the potential range was -1 V to 1 V. The corresponding measurement parameters were an excitation voltage of 1 V, a detection sensitivity of e-5, and a potential step of 0.2 V. Prepare rice soup by taking 10 g of rice, adding 50 mL of distilled water, and boiling for 15 ± 1 min to obtain rice soup.

4. The method for calculating rice taste score based on multiple sensor arrays according to claim 3, wherein: When measuring the sample using the voltammetry method, the W, Ti, and Ag electrodes were immersed in rice soup at the same time to obtain the original voltammetry signals of the three electrodes.

5. The method for calculating rice taste score based on multiple sensor arrays according to any one of claims 1 to 4, wherein Step 2) is: The electronic nose uses a built-in sensor to detect the sample, and the ratio of the conductivity response of the sample to the conductivity response of the ambient air is used as the response value.

6. The method for calculating rice taste score based on multiple sensor arrays according to claim 5, characterized in that The measurement time of step 2) is set to 120 s.

7. The method for calculating rice taste score based on multiple sensor arrays according to any one of claims 1 to 6, wherein The step 3) is: The original voltammetric signal and gas response signal are decomposed by wavelet packet to obtain detail signal, and the detail signal is transformed by fast Fourier transform to obtain amplitude curve; Each metal working electrode and gas sensor obtains its own amplitude curve, and each amplitude curve has a maximum amplitude peak; therefore, each sample has 7 highest amplitudes, which are arranged into a sensing amplitude vector, and then the taste score of the rice sample is calculated.

8. The method for calculating rice taste score based on multiple sensor arrays according to claim 7, wherein: Extract the highest amplitude FZ of the three electrodes and four gas sensors and arrange them into sensing amplitude vectors: ； The sensor amplitude vector is used to calculate the taste score ESc of the rice sample. The formula is as follows: 。

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