Simple method for measuring taste quality of rice

Abstract

The invention discloses a simple method for determining taste quality of rice. The method comprises the following steps: detecting protein content X1 and amylose content X2 in rice; measuring by using a rice taste instrument and adopting a Chinese japonica rice detection line or a Japanese japonica rice detection line to obtain a Chinese japonica rice taste value YCN or a Japanese japonica rice taste value YJP; carrying out regression analysis on X1 and X2 and YCN or YJP, and establishing a special mathematical model Y 'CN for the taste quality of Chinese rice or a special mathematical model Y' JP for the taste quality of Japanese rice; and substituting X1 and X2 of the to-be-detected rice into Y 'CN or Y' JP to calculate the taste value of the to-be-detected rice. The method does not need to be equipped with an expensive rice taste instrument, and is low in measurement condition requirement and low in investment cost. According to the method, the taste values of the Chinese japonica rice detection line and the Japanese japonica rice detection line can be obtained at the same time, conversion and comparison between related data can be achieved, operation is easy, measurement is convenient, repeatability is good, accuracy is high, and application and popularization are convenient.

Description

Technical Field

[0001] The invention relates to a simple method for measuring the taste quality of rice, and belongs to the technical field of food measurement. Background Art

[0002] Rice is one of the three major staple foods in my country, and is mostly eaten directly in the form of cooked rice. The taste quality of rice refers to the hardness, stickiness, elasticity, and cold rice recovery of rice, which is a direct indicator for evaluating whether rice is delicious. Therefore, the taste quality of rice is very important. In recent years, with the improvement of residents' living standards, consumers' demand for rice has gradually changed from "eating enough" to "eating well", and the taste quality of rice has received more and more attention. Therefore, measuring the taste quality of rice is crucial to every link in the entire rice industry chain from breeding, cultivation, and processing.

[0003] At present, the evaluation of rice taste quality mainly includes manual sensory evaluation method and taste meter method. The manual sensory evaluation method has high requirements for evaluators, and the evaluation process is relatively complicated. At the same time, it is affected by the evaluator's personal preferences, living habits and food culture. The test results are highly subjective and have poor repeatability. Different evaluators have different evaluation scales, and it is difficult to compare the evaluation data. The taste meter method is the most commonly used method at present. However, this method requires an expensive rice taste meter. Many units do not have the relevant experimental conditions, and the sample preparation and measurement operation specifications are high. Therefore, it is of great significance to develop a simple and low-cost method for measuring the taste quality of rice and apply it to the above-mentioned special application scenarios.

[0004] Protein and starch are the two main components of rice grains, accounting for about 90% of the dry basis mass. Therefore, the formation of rice taste quality is closely related to protein content and amylose content. Relevant practitioners usually measure the protein content and amylose content in rice first when conducting quality analysis. Therefore, if a mathematical model for calculating rice taste quality based on protein and amylose content is developed, the rice taste quality can be directly estimated without the need to purchase an expensive rice taste meter to measure the taste value. This method is simple and convenient, has low measurement conditions, low investment cost, and is easy to promote, and has important application value. Summary of the invention

[0005] Purpose of the invention: In view of the problem that currently measuring the taste quality of rice usually requires an expensive rice taste meter, which has high cost investment and high professional operation, the purpose of the present invention is to provide a simple method for calculating the taste quality of rice by measuring the protein content and the amylose content.

[0006] Technical solution: The simple method for determining the taste quality of rice described in the present invention comprises the following steps:

[0007] (1) Detecting the protein content X1 and the amylose content X2 in rice;

[0008] (2) preparing rice cakes, placing the rice cakes in a rice taste meter, and measuring using a Chinese japonica rice test line or a Japanese japonica rice test line to obtain the Chinese japonica rice test line taste value Y of the rice cake samples, respectively. CN Or Japanese japonica rice test line taste value Y JP ;

[0009] (3) The protein content X1 and the amylose content X2 obtained in step (1) are compared with the Chinese japonica rice test line taste value Y obtained in step (2) CN Or Japanese japonica rice test line taste value Y JP Perform regression analysis to establish a special mathematical model for the taste value of Chinese japonica rice test line or the taste value of Japanese japonica rice test line;

[0010] (4) Determine the protein content X1 and the amount of amylose X2 of the rice to be tested, and calculate the fitting taste value Y' of the Chinese japonica rice test line of the rice to be tested according to the special mathematical model of the taste value of the Chinese japonica rice test line or the special mathematical model of the taste value of the Japanese japonica rice test line in step (3). CN Or the Japanese japonica rice test line fitting taste value Y' JP .

[0011] Furthermore, in step (1), chemical methods are used for detection.

[0012] Furthermore, according to the operating steps in the national standard "GB 5009.5-2016 National Food Safety Standard Determination of Protein in Food", the protein content X1 of the rice sample was determined by the Kjeldahl nitrogen method.

[0013] Furthermore, according to the operating steps in the national standard "GB / T 15683-2008 Determination of the Amylose Content of Rice", the amylose content X2 of the rice sample was determined by the iodine blue value method.

[0014] Furthermore, in step (2), preparing rice cakes comprises the following steps:

[0015] Take the whole polished rice, wash it, soak it in water, steam it, simmer it, stir it evenly, cool it, put it into the former and press it on both sides.

[0016] Furthermore, when soaking in water, the mass ratio of whole polished rice to water is 1:1-2, preferably 1:1.4, and the soaking time is more than 30 minutes.

[0017] Furthermore, steam for more than 30 minutes, simmer the rice for more than 10 minutes, and press the front and back sides for more than 10 seconds each.

[0018] Furthermore, in step (3), linear regression analysis was performed using SPSS software.

[0019] Furthermore, in step (3), the special mathematical model Y' of the taste value of the Chinese japonica rice detection line CN =122.351-5.114X1-0.583X2, where Y' CN is the taste value of the Chinese japonica rice detection line, X1 is the protein content, and X2 is the amylose content.

[0020] Furthermore, in step (3), the special mathematical model Y' of the taste value of the Japanese japonica rice detection line JP =133.077-7.339X1-1.367X2, where Y' JP is the taste value of Japanese japonica rice test line fitting, X1 is the protein content, and X2 is the amylose content.

[0021] Furthermore, in step (4), the special mathematical model Y' of the taste value of the Chinese japonica rice test line is used. CN =122.351-5.114X1-0.583X2, the fitting taste value Y' of the Chinese japonica rice detection line is calculated CN .

[0022] Furthermore, in step (4), a special mathematical model Y' of the taste value of the Japanese japonica rice test line is used. JP =133.077-7.339X1-1.367X2, the fitting taste value Y' of the Japanese japonica rice test line is calculated JP ;.

[0023] Furthermore, the Chinese japonica rice test line calculated in step (4) can be fitted with the taste value Y' CN And the Japanese japonica rice test line fitting taste value Y' JP Regression analysis was performed to obtain the fitting taste value Y' of the Chinese japonica rice detection line CN Fitting the taste value Y' with the Japanese japonica rice test line JP The mathematical model is then used to fit the taste value Y' based on the obtained Chinese japonica rice detection line CN Or the Japanese japonica rice test line fitting taste value Y' JP The corresponding Japanese japonica rice test line fitting taste value Y' can be obtained respectively JP Or the Chinese japonica rice test line fitting taste value Y' CN , to achieve mutual conversion and comparison between data.

[0024] Furthermore, the Chinese japonica rice test line fitted the taste value Y' CN Fitting the taste value Y' with the Japanese japonica rice test line JP The mathematical model is Y' CN=0.4949Y' JP +47.641, of which Y' CN is the taste value of the Chinese japonica rice test line calculated in step (4) or Y' JP The fitting taste value of the Japanese japonica rice detection line calculated in step (4).

[0025] The method of the present invention is based on the determination of the protein content and the amylose content of rice by chemical titration. By analyzing the relationship between the protein content, the amylose content and the rice taste value, a special mathematical model suitable for evaluating the rice taste quality is established: a mathematical model for estimating the fitting taste value under the Japanese japonica rice detection line: Y' JP =133.077-7.339X1-1.367X2; the mathematical model of the fitting taste value under the Chinese japonica rice detection line can be estimated: Y' CN =122.351-5.114X1-0.583X2. Among them, Y' JP or Y' CN represents the fitted taste value, X1 represents the protein content, and X2 represents the amylose content. On this basis, the above mathematical model is further used to calculate the fitted taste value of rice (Y' JP or Y' CN ) and the taste quality was evaluated.

[0026] The determination method of the present invention is simple to operate, has low requirements on determination conditions, does not require an expensive rice taste meter, can simultaneously obtain the rice taste values ​​below the Japanese japonica rice detection line and the Chinese japonica rice detection line, can realize the conversion and comparison between the determination data of different detection lines, has high determination result accuracy, has high discrimination degree for different rice samples, is close to the result of the currently commonly used taste meter method, and is a feasible simple method for determining the rice taste quality by chemical method.

[0027] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0028] (1) Compared with the currently commonly used rice taste meter method, the rice taste quality determination method provided by the present invention does not require an expensive rice taste meter, has low determination condition requirements, and has low investment cost.

[0029] (2) The rice taste quality determination method provided by the present invention can simultaneously obtain the taste values ​​below the Chinese japonica rice detection line and the Japanese japonica rice detection line, and can realize the conversion and comparison between related data. It is simple to operate, convenient to determine, has good repeatability, high accuracy, and is easy to promote and apply. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is further described below.

[0031] Example 1 Establishment Method

[0032] Step 1: Select 30 rice varieties with different taste qualities (see Table 1), and determine the protein content of rice samples by Kjeldahl method according to the operating steps in the national standard "GB 5009.5-2016 National Food Safety Standard Determination of Protein in Food" (X1).

[0033] Step 2: The sample obtained in step 1 is further subjected to the iodine blue value method to determine the amylose content (X2) according to the operating procedures in the national standard GB / T 15683-2008 Determination of Amylose Content in Rice.

[0034] Step 3: Prepare rice cakes: Weigh 30g of the whole polished rice of the above rice sample, wash it, add water according to the rice-water mass ratio of 1:1.4, soak it for 30 minutes, add it to the steamer and cook it for 30 minutes, and simmer it for 10 minutes. Stir the rice evenly, put it in a cooling box to cool it for 20 minutes, and then transfer it to room temperature to cool it for 90 minutes. Weigh 8g of rice, add it to the round former, and press it on both sides for 10 seconds to obtain rice cakes.

[0035] Step 4: Place the rice cakes in the Satake STA1B rice taste meter and measure them using the Japanese japonica rice test line to obtain the taste values ​​(Y JP ).

[0036] Step 5: Place the rice cakes in the Satake STA1B rice taste meter and measure them using the Chinese japonica rice test line to obtain the taste values ​​(Y CN ).

[0037] The protein content (X1), amylose content (X2) and taste values ​​of the 30 rice varieties measured by the rice taste meter are shown in Table 1.

[0038] Step 6: SPSS software was used to compare the protein content (X1) of the rice sample obtained in step 1, the amylose content (X2) of the rice sample obtained in step 2, and the taste value (Y JP ) to conduct regression analysis and establish a special mathematical model for the taste value of Japanese japonica rice detection line: fitting the taste value Y' JP =133.077-7.339X1-1.367X2, the correlation coefficient is R=0.927, and the correlation is good.

[0039] Step 7: Using SPSS software, the protein content (X1) of the rice sample obtained in step 1, the amylose content (X2) of the rice sample obtained in step 2, and the taste value (Y CN) to conduct regression analysis and establish a special mathematical model for the taste value of Chinese japonica rice detection line: fitting the taste value Y' CN =122.351-5.114X1-0.583X2, the correlation coefficient is R=0.892, and the correlation is good.

[0040] Step 8: Substitute the protein content (X1) of the rice samples obtained in step 1 and the amylose content (X2) of the rice samples obtained in step 2 into Y' JP =133.077-7.339X1-1.367X2 and Y' CN =122.351-5.114X1-0.583X2 to get Y' JP Fitted values ​​and Y' CN The fitting results are shown in Table 1.

[0041] Table 1 Related parameters of different rice samples

[0042]

[0043]

[0044] As can be seen from Table 1, the taste values ​​calculated by using the taste value fitting mathematical model of the Japanese japonica rice detection line and the taste value fitting mathematical model of the Chinese japonica rice detection line in the present invention are very close to the taste values ​​measured by the taste meter, with average absolute errors of 2.30 and 1.61 respectively, with high accuracy and good substitutability.

[0045] Step 9: Use SPSS software to fit the taste value (Y' JP ) and the taste value of Chinese japonica rice detection line fitting (Y' CN ) to perform regression analysis and obtain the fitting taste value Y' of the Chinese japonica rice detection line CN Fitting the taste value Y' with the Japanese japonica rice test line JP The mathematical model is: CN =0.4949Y' JP +47.641, the correlation coefficient is R=0.945, and the correlation is good. By inputting the taste value measured under a certain detection line, the taste value under another detection line can be obtained, and the mutual conversion and comparison between data can be realized.

[0046] The Y' JP Substitute Y' CN =0.4949Y' JP +47.641, calculated as Y' CN , the results are shown in Table 2.

[0047] Table 2 Fitting taste values ​​of different rice samples

[0048]

[0049]

[0050] As can be seen from Table 2, by using the Japanese japonica rice test line fitting taste value and the Chinese japonica rice test line fitting taste value conversion model of the present invention, the Japanese japonica rice test line fitting taste value or the Chinese japonica rice test line fitting taste value is calculated, and the average absolute error is 0.44, which is highly accurate. Therefore, the rice taste value measured under a certain test line can be input to obtain the taste value under another test line, thereby realizing the mutual conversion and comparison between data.

[0051] Example 2 Accuracy Verification Test

[0052] Verify the accuracy of the mathematical model for fitting the taste value of the Japanese japonica rice detection line of the method of the present invention.

[0053] Step 1: According to the operating steps in the national standard "GB 5009.5-2016 National Food Safety Standard Determination of Protein in Food", the protein content of sample Yangjing 9299 was determined by Kjeldahl method X1=7.05.

[0054] Step 2: According to the operating steps in the national standard "GB / T 15683-2008 Determination of the Amylose Content of Rice", the amylose content of the sample Yangjing 9299 was determined by the iodine blue value method, X2=11.23.

[0055] Step 3: Using the method established in Example 1, the Japanese japonica rice test line taste value special mathematical model Y' JP =133.077-7.339X1-1.367X2, calculate the fitting taste value of Japanese japonica rice detection line: Y' JP =65.99.

[0056] Step 4: Take 30g of Yangjing 9299 whole polished rice, wash it, add water according to the rice-water mass ratio of 1:1.4, soak it for 30 minutes, add it to the steamer and cook it for 30 minutes, and simmer it for 10 minutes. Stir it evenly, put it in a cooling box to cool it for 20 minutes, and then transfer it to room temperature to cool it for 90 minutes. Weigh 8g of rice, add it to the round former, press it on both sides for 10 seconds to get a rice cake. Place the rice cake in the rice taste meter, and use the Japanese japonica rice test line to determine the taste value of the sample Yangjing 9299: Y JP =63.48.

[0057] Step 5: Fitting the taste value Y' of the lower Japanese japonica rice detection line calculated by the method of the present invention in step 3 JPThe Japanese japonica rice test line taste value Y measured by the rice taste meter in step 4 JP Compare and calculate the error rate (%) of the two methods as |Y' JP -Y JP |×100 / Y JP =3.80. It is proved that the present invention has high accuracy in measuring the rice taste value by fitting the mathematical model of the taste value of the Japanese japonica rice test line, and can replace the Japanese test line method of the taste meter.

[0058] Example 3 Accuracy Verification Test

[0059] Verify the accuracy of the mathematical model for fitting the taste value of the Chinese japonica rice detection line of the method of the present invention.

[0060] Step 1: According to the operating steps in the national standard "GB 5009.5-2016 National Food Safety Standard Determination of Protein in Food", the protein content of sample Yangjing 9299 was determined by Kjeldahl method X1=7.05.

[0061] Step 2: According to the operating steps in the national standard "GB / T 15683-2008 Determination of the Amylose Content of Rice", the amylose content of the sample Yangjing 9299 was determined by the iodine blue value method, X2=11.23.

[0062] Step 3: Using the method established in Example 1, the special mathematical model Y' of the taste value of the Chinese japonica rice test line is used. CN =122.351-5.114X1-0.583X2, calculate the fitting taste value of the Chinese japonica rice detection line: Y' CN =79.75.

[0063] Step 4: Take 30g of whole polished rice of rice sample 1, wash it, add water according to the rice-water mass ratio of 1:1.4, soak it for 30 minutes, add it to the steamer and cook it for 30 minutes, and simmer it for 10 minutes. Stir it evenly, put it in a cooling box to cool it for 20 minutes, and then transfer it to room temperature to cool it for 90 minutes. Weigh 8g of rice, add it to the round former, press it on both sides for 10 seconds to get rice cakes. Place the rice cakes in the rice taste meter, and use the Chinese japonica rice detection line to determine the taste value of the sample Yangjing 9299: Y CN =78.53.

[0064] Step 5: Fit the taste value Y' of the Chinese japonica rice test line calculated by the method of the present invention in step 3 CN The Chinese japonica rice test line taste value Y measured by the rice taste instrument in step 4 CN Compare and calculate the error rate (%) of the two methods as |Y' CN -Y CN |×100 / Y CN=1.53. It is proved that the present invention has high accuracy in measuring the rice taste value by fitting the mathematical model of the taste value of the Chinese japonica rice test line, and can replace the Chinese test line method of the taste meter.

Claims

1. A simple method for determining the taste quality of rice, characterized in that: The following steps are involved: (1) Detecting the protein content X1 and the amylose content X2 in rice; (2) Prepare rice cakes, place the rice cakes in a rice taste meter, and measure them using the Chinese japonica rice or Japanese japonica rice test line to obtain the Chinese japonica rice test line taste value Y of the rice cake samples. CN Or Japanese japonica rice test line taste value Y JP ; (3) The protein content X1 and the amylose content X2 obtained in step (1) are compared with the Chinese japonica rice test line taste value Y obtained in step (2) CN Or Japanese japonica rice test line taste value Y JP Perform regression analysis to establish a special mathematical model for the taste value of Chinese japonica rice test line or the taste value of Japanese japonica rice test line; (4) Determine the protein content X1 and the amount of amylose X2 of the rice to be tested, and calculate the fitting taste value Y' of the Chinese japonica rice test line of the rice to be tested according to the special mathematical model of the taste value of the Chinese japonica rice test line or the special mathematical model of the taste value of the Japanese japonica rice test line in step (3). CN Or the Japanese japonica rice test line fitting taste value Y' JP .

2. The simple method for measuring the taste quality of rice according to claim 1, characterized in that: In step (1), chemical methods are used for detection.

3. The simple method for measuring the taste quality of rice according to claim 1, characterized in that: In step (2), preparing rice cakes comprises the following steps: Take the whole polished rice, wash it, soak it in water, steam it, simmer it, stir it evenly, cool it, put it into the former and press it on both sides.

4. The simple method for measuring the taste quality of rice according to claim 3, characterized in that: When adding water for soaking, the mass ratio of whole polished rice to water is 1:1-2, and soak for more than 30 minutes.

5. The simple method for measuring rice taste quality according to claim 3, characterized in that: Steam for more than 30 minutes, simmer the rice for more than 10 minutes, and press on both sides for more than 10 seconds each.

6. The simple method for measuring the taste quality of rice according to claim 1, characterized in that: In step (3), linear regression analysis was performed using SPSS software.

7. The simple method for measuring rice taste quality according to claim 1, characterized in that: In step (3), the special mathematical model Y' of the taste value of the Chinese japonica rice test line CN =122.351-5.114X1-0.583X2, where Y' CN is the taste value of the Chinese japonica rice detection line, X1 is the protein content, and X2 is the amylose content.

8. The simple method for measuring rice taste quality according to claim 1, characterized in that: In step (3), the special mathematical model Y' of the taste value of the Japanese japonica rice test line JP =133.077-7.339X1-1.367X2, where Y' JP is the taste value of Japanese japonica rice test line fitting, X1 is the protein content, and X2 is the amylose content.

9. The simple method for measuring the taste quality of rice according to claim 1, characterized in that: The Chinese japonica rice test line calculated in step (4) can also be fitted with the taste value Y' CN Fitting taste value Y' of Japanese japonica rice test line JP Regression analysis was performed to obtain the fitting taste value Y' of the Chinese japonica rice detection line CN Fitting the taste value Y' with the Japanese japonica rice test line JP The mathematical model is then used to fit the taste value Y' based on the obtained Chinese japonica rice detection line CN Or the Japanese japonica rice test line fitting taste value Y' JP The corresponding Japanese japonica rice test line fitting taste value Y' can be obtained respectively JP Or the Chinese japonica rice test line fitting taste value Y' CN , to achieve mutual conversion and comparison between data.

10. The simple method for measuring rice taste quality according to claim 9, characterized in that: Fitting taste value of Chinese japonica rice detection line Y' CN Fitting the taste value Y' with the Japanese japonica rice test line JP The mathematical model is Y' CN =0.4949Y' JP +47.641, of which Y' CN is the taste value of the Chinese japonica rice test line calculated in step (4) or Y' JP The fitting taste value of the Japanese japonica rice detection line calculated in step (4).

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