TW202311726A - Real-time monitoring method of tea raw material extraction degree capable of directly determining the tea raw material extraction degree without interference of the tea raw material - Google Patents

Abstract

A real-time monitoring method of tea raw material extraction degree is disclosed, which includes: extracting raw material components containing tea raw materials to obtain tea extract; and during the extraction process, using a sensing unit to monitor the tea extract in real time to obtain the total amount of soluble solids and redox potential at different times. When one of the following conditions is met, the extraction process will be stopped at any time after the monitoring time point of the condition: (1) the slope of the line segment formed by the total amount of soluble solids is -2.5 to less than 3.5 and the slope of the line segment formed by the redox potential is -5 to -0.1 at the same monitoring time point; (2) the positive and negative signs of the change rates of the total amount of soluble solids at two adjacent monitoring time points are opposite; and (3) the positive and negative signs of the change rates of redox potential at two adjacent monitoring time points are opposite.

Description

Real-time monitoring method of extraction degree of tea raw materials

The invention relates to a method for judging the extraction degree, in particular to a real-time monitoring method for the extraction degree of tea raw materials.

In the current bottled tea drinking process in food factories, in order to confirm the quality of the tea soup, it is usually necessary to take samples during the extraction process of the tea leaves, and judge the degree of extraction of the tea leaves by testing the tea soup and observing the color of the tea soup. Such an artificial judgment method has no scientific standards, and different testers have different feelings about the tea taste of tea soup. Therefore, the above-mentioned method of judging the degree of extraction of tea leaves not only requires additional sampling for analysis, but also causes problems in the production process. Inconvenience, and there is the problem of inhomogeneous quality in the tea soup obtained by this method.

On the other hand, in order to accurately judge the extraction degree of tea leaves, there is currently an online monitoring of the tea soup by using an optical monitoring method. However, because the tea leaves still exist in the tea soup during the online monitoring process, therefore , the optical monitoring method is susceptible to the influence of the monitoring results by the presence of the tea leaves.

Therefore, the object of the present invention is to provide a real-time monitoring method of the extraction degree of tea raw material.

Thus, the real-time monitoring method of the tea raw material extraction degree of the present invention comprises the following steps: The raw material components including water and tea raw materials are placed in an extraction device including a sensing unit for extraction treatment to obtain a tea extract, wherein the tea raw materials are selected from black tea leaves, green tea leaves, oolong tea leaves or Herbal tea ingredients containing grass jelly, peppermint, xianfengcao and houttuynia cordata; and During the extraction process, use the sensing unit to monitor the tea extract over time to obtain the total amount of soluble solids at different times and the redox potential at different times, and when one of the following conditions is met , then stop the extraction process at any time after the monitoring time point of the condition, Condition 1 is that the slope of the line segment formed by the total amount of soluble solids at two adjacent monitoring time points ranges from -2.5 to less than 3.5 and the slope of the line segment formed by the oxidation-reduction potentials at the two adjacent monitoring time points The slope ranges from -5 to -0.1; The second condition is that the positive and negative signs of the rate of change of the total soluble solids at two adjacent monitoring time points are opposite; and The third condition is that the positive and negative signs of the change rates of the redox potentials at two adjacent monitoring time points are opposite.

The efficacy of the present invention lies in: the tea extract is monitored in real time during the extraction process of the tea raw material through the sensing unit, and the real-time monitoring method of the extraction degree of the tea raw material of the present invention does not need to be automatically detected during the extraction process. Take out a little tea extract from the extraction device and confirm the extraction degree of the tea raw material through human tasting or human judgment of color, so as to reduce the error caused by human judgment. In addition, by monitoring the total soluble solids data and redox potential data of the tea extract, the method for real-time monitoring of the extraction degree of the tea raw material of the present invention can directly determine the extraction degree of the tea raw material without being disturbed by the tea raw material.

The method for monitoring the extraction degree of tea raw materials of the present invention includes: using a sensing unit to monitor the extraction degree of the taste substances of the tea raw materials during the extraction process of the raw material components placed in an extraction device and including water and tea raw materials. The taste-imparting substances are, for example, tea polyphenols that provide astringent taste or theanine that provide sweet taste. In some embodiments of the present invention, the taste substances are tea polyphenols and theanine. The raw material components, sensing unit, and extraction process of the present invention will be described in detail below.

" Raw material components "

The black tea leaves are, for example, tea leaves of the small-leaf tea plant, No. 8 Taicha, No. 18 Taicha, and the like. The green tea leaves are, for example, tea leaves obtained from Qingxin mandarin tea tree or Qingxin oolong tea tree through Biluochun process, tea leaves from Chinese Longjing green tea tree, Taiwan tea No. 12, etc. The oolong tea leaves are, for example, tea leaves from Qingxin oolong tea trees or Taicha No. 12 made by Baozhong tea production method, tea leaves harvested from oolong tea trees planted at an altitude of more than 1,000 meters, and the source of the variety is Lugu Township, Nantou County The tea leaves of Qingxin Oolong tea tree, the tea leaves of Tieguanyin tea tree, etc. For example, the grass jelly is harvested from September to October every year and produced in places such as Hsinchu Kansai, Miaoli Tongluo, Taoyuan Xinwu, Hualien Fenglin, etc. in Taiwan. The mint is for example spearmint. The Xianfengcao is, for example, Xianfengcao daflora. The houttuynia cordata is, for example, produced in Taiwan and harvested from June to July and from September to October every year.

In some embodiments of the present invention, in order to obtain a better extraction amount of flavoring substances to achieve appropriate extraction benefits, based on the total amount of the raw material components being 100 kg, the amount of the tea raw material ranges from 1 kg to 7.5 kg.

"Sensing Unit"

In some embodiments of the present invention, the sensing unit is a sensor capable of measuring the total amount of soluble solids and the redox potential. In some embodiments of the present invention, the sensing unit includes a total soluble solids sensor and an oxidation-reduction potential sensor.

"Extraction Treatment"

In some embodiments of the present invention, the temperature of the extraction treatment ranges from 50°C to 90°C.

"Establishment of a real-time monitoring method for the extraction degree of black tea leaves"

State 1 The dosage of black tea leaves is 7.5wt%

The raw material components of 92.5 kg of water and 7.5 kg of black tea leaves (place of origin: Taiwan; type: tea leaves of small-leaved tea tree) are placed in a sensor for total soluble solids (brand: SUNTEX; model: SC-110) and oxidation-reduction potential sensor (brand: JENCO; model: 6010M) extraction device, and at 90 ℃ for extraction treatment, wherein, in the process of the extraction treatment at 0 minutes, At 10 minutes, 20 minutes, 30 minutes, 40 minutes, 60 minutes, 90 minutes, 120 minutes and 180 minutes, a little tea extract was taken out from the extraction device as a test sample, and the ultraviolet-visible light spectrometer (brand name : Merck; Model: Spectroquant ^® Pharo 300) Analyze the extraction amount of tea polyphenols and theanine in each test sample, and use the tea polyphenols in the test sample with the largest extraction amount of tea polyphenols in the test samples The extraction amount of theanine is calculated as 100%, and the extraction amount of theanine in the detection sample with the maximum extraction amount of theanine in these test samples is calculated as 100%, and the tea polyphenols and tea polyphenols in the remaining test samples are converted. The relative extraction amount of amino acid, the results are shown in Table 1, and according to the results in Table 1, the extraction amount and extraction time curve of tea polyphenols and theanine is drawn, as shown in Figure 1.

Simultaneously, during the extraction process, the total soluble solids sensor and the oxidation-reduction potential sensor also regularly monitor the tea extract, and provide the tea extract at each monitoring point The results of total soluble solids and redox potential are shown in Table 1, and according to the results in Table 1, the curves of total soluble solids, redox potential and extraction time are drawn, as shown in Figure 2.

Table 1 State one tea raw material type black tea leaves Dosage(kg) 7.5 water Dosage(kg) 92.5 Extraction temperature(℃) 90 time (minutes) 0 10 20 30 40 60 90 120 180 Tea polyphenols Extraction amount (μg/mL) 121 2729 3459 3615 3721 4015 3906 3797 3524 Relative extraction amount (%) 3 68 86.2 90 92.7 100 97.3 94.6 87.8 Theanine Extraction amount (μg/mL) 44 706 915 951 966 922 889 911 891 Relative extraction amount (%) 4.6 73.1 94.8 98.4 100 95.4 92 94.4 92.3 Total soluble solids (ppm) 181 902 982 1024 1000 975 956 926 900 Slope of total soluble solids - 72.2 8.0 4.2 -2.4 -1.3 -0.6 -1.0 -0.4 Change rate of total soluble solids (%) - 399.7 8.9 4.2 -2.3 -2.5 -1.9 -3.1 -2.9 Oxidation-reduction potential (mv) 195 182 168 161 155 158 156 158 158 The slope of the redox potential - -1.3 -1.4 -0.7 -0.6 0.2 -0.1 0.1 0 Change rate of redox potential (%) - -6.7 -7.7 -4.2 -3.7 1.9 -1.0 1.3 0

Referring to Table 1 and Fig. 1, at 0 minutes to 40 minutes, the extraction amount of tea polyphenols and theanine in these test samples increased with time, and at 40 minutes, there was a relative The tea polyphenols and theanine with an extraction amount of more than 90% are extracted from the black tea leaves, and after 40 minutes, the extraction amount of the tea polyphenols and theanine in the tea extract It is similar, so that the multiple line segments formed by the extraction amounts of two adjacent tea polyphenols and the multiple line segments formed by the extraction amounts of two adjacent theanines are approaching levels.

Referring to Fig. 1 and Fig. 2, when 0 minute to 40 minutes, the redox potential of the tea extract of each monitoring time point decreases as time increases, and the total amount of soluble solids increases as time increases, and the The extraction amount of tea polyphenols and theanine in the tea extract increased with time. It can be seen that the redox potential and the extraction amount of tea polyphenols and theanine showed a negative relationship between 0 minutes and 40 minutes. Correlation, and the total amount of soluble solids is positively correlated with the extraction amount of tea polyphenols and theanine, and after 40 minutes, the oxidation-reduction potentials of the tea extract are roughly similar and the total amount of soluble solids is also roughly similar, and the plural line segments formed by two adjacent oxidation-reduction potentials are approaching levels, and the plural line segments consisting of two adjacent total soluble solids are also approaching levels, which is the same as that in the tea extract The extraction of tea polyphenols and theanine after 40 minutes. From the above, it can be seen that the change trend of the oxidation-reduction potential of the tea extract and the total amount of soluble solids is related to the change trend of the extraction amount of tea polyphenols and theanine in the tea extract. Therefore, the redox potential and soluble The total amount of solids can be used as an indicator of the extraction degree of flavor substances in black tea leaves.

Also, the slope of the line segment formed by the oxidation-reduction potentials of the tea extract at 30 minutes and 40 minutes is -0.6 [that is, (155-161)/(40-30)], and at the same time, the total soluble solids The slope of the line segment formed by the amount of tea is -2.4 [that is, (1000-1024)/(40-30)], and such a slope just reflects the relative extraction amount of tea polyphenols and theanine in the tea extract It has reached more than 90%. Therefore, the extraction treatment can meet the slope of the line segment formed by the redox potential at the same monitoring time point from -5 to 0.1 and the slope of the line segment formed by the total amount of soluble solids to meet -2.5 Stop at any time after the monitoring time point when it is above and less than 3.5.

In addition to using the slope as a judgment to stop the extraction process, the rate of change of the total soluble solids of the tea extract at 30 minutes and 40 minutes showed opposite signs, and at 30 minutes, the rate of change was 4.2%{ That is, [(1024-982)/982] × 100%}, and at 40 minutes, the rate of change is -2.3% {ie, [(1000-1024)/1024] × 100%}, and the positive and negative signs begin to appear The opposite phenomenon just reflects that the relative extraction amount of tea polyphenols and theanine in the tea extract has reached more than 90%, and the relative extraction amount of at least one of the tea polyphenols and the theanine has reached 95%. % or more, therefore, the extraction process can be stopped at any time after the monitoring time point when the rate of change of the total soluble solids shows a phenomenon of opposite signs.

In order to confirm the correlation between the redox potential of the tea extract and the total amount of soluble solids and the extraction amount of tea polyphenols and theanine in the tea extract, the Pearson Correlation Coefficient (Pearson Correlation Coefficient) was calculated using the CORREL function , and the results are shown in Table 2.

Table 2 State one Pearson correlation coefficient Tea polyphenols Theanine redox potential -0.936 -0.950 Total Soluble Solids 0.986 0.976

Referring to Table 2, there is indeed a high correlation between the oxidation-reduction potential and the total amount of soluble solids of the tea extract and the extraction amounts of tea polyphenols and theanine in the tea extract. Therefore, the oxidation-reduction potential and the total amount of soluble solids can indeed be used as indicators of the extraction degree of taste substances in black tea leaves.

Pattern 2 The dosage of black tea leaves is 2.5wt%

The method for real-time monitoring of the extraction degree of black tea leaves in Aspect 2 is similar to the method for real-time monitoring of the extraction degree of black tea leaves in Aspect 1. The difference is that the dosage ratio of black tea leaves and the monitoring time are changed, as shown in Table 3.

table 3 Pattern two tea raw material type black tea leaves Dosage(kg) 2.5 water Dosage(kg) 97.5 Extraction temperature(℃) 90 time (min) 0 10 20 30 40 50 60 Tea polyphenols Extraction amount (μg/mL) 97.4 958.8 1358.8 1564.7 1770.6 1852.9 1870.6 Relative extraction amount (%) 5 51.3 72.6 83.6 94.7 99.1 100 Theanine Extraction amount (μg/mL) 27.5 253.2 291.1 313.9 343.0 339.2 332.9 Relative extraction amount (%) 8 73.8 84.9 91.5 100 98.9 97 Total soluble solids (ppm) 92 400 457 475 489 500 510 Slope of total soluble solids - 30.8 5.7 1.8 1.4 1.1 1.0 Change rate of total soluble solids (%) - 334.8 14.3 3.9 2.9 2.2 2.0 Oxidation-reduction potential (mv) 135 112 70 -9 -56 -62 -68 The slope of the redox potential - -2.3 -4.2 -7.9 -4.7 -0.6 -0.6 Change rate of redox potential (%) - -17.0 -37.5 -112.9 522.2 10.7 9.7

Referring to Table 3 and Figure 3, the trend of the extraction amount of tea polyphenols and theanine in the tea extract of the second aspect is the same as that of the first aspect, so it will not be repeated.

Referring to Figure 3 and Figure 4, the correlation between the total amount of soluble solids and the redox potential of the tea extract of the second aspect and the extraction amount of tea polyphenols and theanine in the tea extract is the same as that of the first aspect, so it is not Let me repeat. In the second aspect, the slope of the line segment formed by the oxidation-reduction potentials and the slope of the line segment formed by the total amount of soluble solids are respectively -4.7{that is, [-56-(-9)]/(40 -30)} and 1.4 [ie, (489-475)/(40-30)]. The rate of change of the oxidation-reduction potential of the tea extract showed opposite signs of positive and negative signs, and at 30 minutes, the rate of change was -112.9% {that is, {[(-9)-70]/70}×100% }, while at 40 minutes, the rate of change was 522.2% {ie, {[-56-(-9)]/(-9)}×100%}.

Table 4 Pattern two Pearson correlation coefficient Tea polyphenols Theanine redox potential -0.923 -0.887 Total Soluble Solids 0.980 0.991

Referring to Table 4, there is indeed a high correlation between the oxidation-reduction potential and the total amount of soluble solids of the tea extract and the extraction amount of tea polyphenols and theanine in the tea extract. Therefore, the oxidation-reduction potential and soluble solids The total amount can indeed be used as an indicator of the degree of extraction of flavor substances in black tea leaves. In addition, compared to the 7.5wt% amount of black tea leaves used in the aspect 1, the aspect 2 operates under the condition of 2.5wt% black tea leaves, and the monitoring results are not too different from the aspect 1. There is a large difference, which means that the change of the amount of black tea leaves does not affect the result of the present invention using the sensing unit to monitor the extraction degree of black tea leaves.

Pattern 3 The amount of black tea leaves is 25kg, and the amount of water is 975kg

The real-time monitoring method of the extraction degree of black tea leaves of the third aspect is similar to the instant monitoring method of the extraction degree of the black tea leaves of the second aspect, the difference is: changing the amount of black tea leaves and water, as shown in Table 5, and adopting a method that can be used at the same time Water quality monitoring digital sensor (brand: HACH; model: SC200TM) for measuring total soluble solids and redox potential.

table 5 Pattern Three tea raw material type black tea leaves Dosage(kg) 25 water Dosage(kg) 975 Extraction temperature(℃) 82.5 time (min) 0 10 20 30 40 50 60 Tea polyphenols Extraction amount (μg/mL) 97.4 2117.6 2691.2 3488.2 3573.5 3852.9 3882.4 Relative extraction amount (%) 2.5 54.5 69.3 90 92 99.2 100 Theanine Extraction amount (μg/mL) 27.5 205.1 246.8 292.4 300.0 303.8 306.3 Relative extraction amount (%) 9 66.9 80.6 95.5 97.9 99.2 100 Total soluble solids (ppm) 400 620 742 766 769 777 785 Slope of total soluble solids - 22.0 12.2 2.4 0.3 0.8 0.8 Change rate of total soluble solids (%) - 55.0 19.7 3.2 0.4 1.0 1.0 Oxidation-reduction potential (mv) 86 63 -87 -122 -156 -169 -171 The slope of the redox potential - -2.3 -15 -3.5 -3.4 -1.3 -0.2 Change rate of redox potential (%) - -26.7 -238.1 40.2 27.9 8.3 1.2

Referring to Table 5 and Figure 5, from 0 minute to 30 minutes, the extraction amount of tea polyphenols and theanine in these test samples increased with time, and at 30 minutes, the relative extraction amount was More than 90% of the tea polyphenols and theanine are extracted from the black tea leaves, and after 30 minutes, the extraction amounts of the tea polyphenols and the theanine in the tea extracts are similar, making A plurality of line segments formed by two adjacent extraction amounts of tea polyphenols and a plurality of line segments formed by two adjacent extraction amounts of theanine are approach levels.

Referring to Figure 5 and Figure 6, at 0 minutes to 30 minutes, the oxidation-reduction potential of the tea extract at each monitoring time point decreases as time increases, and the total amount of soluble solids increases as time increases, and the The extraction amount of tea polyphenols and theanine in the tea extract increased with time. It can be seen that the redox potential and the extraction amount of tea polyphenols and theanine showed a negative relationship between 0 minutes and 30 minutes. Correlation, and the total amount of soluble solids was positively correlated with the extraction amount of tea polyphenols and theanine. From the above, it can be seen that the change trend of the oxidation-reduction potential of the tea extract and the total amount of soluble solids is related to the change trend of the extraction amount of tea polyphenols and theanine in the tea extract. Therefore, the redox potential and soluble The total amount of solids can be used as an indicator of the extraction degree of flavor substances in black tea leaves.

Also, the slope of the line segment formed by the oxidation-reduction potentials of the tea extract at 20 minutes and 30 minutes is -3.5{that is, [-122-(-87)]/(30-20)}, and at the same time, the The slope of the line segment formed by the total amount of soluble solids is 2.4 [that is, (766-742)/(40-30)], and such a slope just reflects the content of tea polyphenols and theanine in the tea extract. The relative extraction amount has reached more than 90%. Therefore, the extraction process can meet the slope of the line segment formed by the redox potential at the same monitoring time point from -5 to 0.1 and the slope of the line segment formed by the total amount of soluble solids. Stop at any time after the monitoring time point when -2.5 or more and less than 3.5 is satisfied.

In addition to using the slope as a judgment to stop the extraction process, the change rates of the redox potentials of the tea extract at 20 minutes and 30 minutes showed opposite signs, and at 20 minutes, the rate of change was -238.1%{ That is, {[(-87)-63]/63}×100%}, while at 30 minutes, the rate of change is 40.2%{that is, {[-122-(-87)]/(-87)}× 100%}, and the phenomenon of opposite positive and negative signs just reflects that the relative extraction amount of tea polyphenols and theanine in the tea extract has reached more than 90%, and the tea polyphenols and theanine at least The relative extraction amount of one has reached more than 95%. Therefore, the extraction process can be stopped at any time after the monitoring time point when the change rate of the redox potential shows a phenomenon of opposite signs.

Table 6 Pattern three Pearson correlation coefficient Tea polyphenols Theanine redox potential -0.923 -0.887 Total Soluble Solids 0.980 0.991

Referring to Table 6, there is indeed a high correlation between the oxidation-reduction potential and the total amount of soluble solids of the tea extract and the extraction amount of tea polyphenols and theanine in the tea extract. Therefore, the oxidation-reduction potential and soluble solids The total amount can indeed be used as an indicator of the degree of extraction of flavor substances in black tea leaves. In addition, compared with the pilot production (pilot run) of the second aspect, the third aspect operates under the condition of mass production (mass production), and the monitoring results are not much different from the second aspect, which means that it will The amount of black tea leaves and water is enlarged to mass production conditions, and it is also suitable for monitoring the extraction degree of black tea leaves through the sensing unit.

Pattern 4 The extraction temperature is 50°C

The real-time monitoring method of the extraction degree of black tea leaves in Aspect 4 is similar to the real-time monitoring method of the extraction degree of black tea leaves in Aspect 2, the difference is that the extraction temperature is changed, as shown in Table 7.

Table 7 Pattern four tea raw material type black tea leaves Dosage(kg) 2.5 water Dosage(kg) 97.5 Extraction temperature(℃) 50 time (min) 0 20 40 50 60 80 100 120 Tea polyphenols Extraction amount (μg/mL) 0 550 641 679 688 674 679 671 Relative extraction amount (%) 0 79.9 93.2 98.7 100 97.9 98.7 97.4 Theanine Extraction amount (μg/mL) 0 296 394 410 422 427 432 432 Relative extraction amount (%) 0 68.6 91.2 95 97.7 98.8 100 100 Total soluble solids (ppm) 17 301 367 388 384 387 391 391 Slope of total soluble solids - 14.2 3.3 2.1 -0.4 0.2 0.2 0 Change rate of total soluble solids (%) - 1670.6 21.9 5.7 -1.0 0.8 1.0 0 Oxidation-reduction potential (mv) 186 138 131 127 125 123 122 123 The slope of the redox potential - -2.4 -0.4 -0.4 -0.2 -0.1 -0.1 0.1 Change rate of redox potential (%) - -25.8 -5.1 -3.1 -1.6 -1.6 -0.8 0.8

Referring to Table 7 and Figure 7, from 0 minute to 40 minutes, the extraction amount of tea polyphenols and theanine in these test samples increased with time, and at 40 minutes, the relative extraction amount was More than 90% of tea polyphenols and theanine are extracted from the black tea leaves. After 40 minutes, the extraction amounts of the tea polyphenols and the theanine in the tea extracts were similar, so that the multiple line segments formed by the extraction amounts of two adjacent tea polyphenols and the complex numbers consisted of two phases The line segment formed by the extraction amount of adjacent theanine is the approaching level.

Referring to Figure 7 and Figure 8, at 0 minutes to 40 minutes, the oxidation-reduction potential of the tea extract at each monitoring time point decreases as time increases, and the total amount of soluble solids increases as time increases, and the The extraction amount of tea polyphenols and theanine in the tea extract increased with time. It can be seen that the redox potential and the extraction amount of tea polyphenols and theanine showed a negative relationship between 0 minutes and 40 minutes. Correlation, and the total amount of soluble solids is positively correlated with the extraction amount of tea polyphenols and theanine, and after 40 minutes, the oxidation-reduction potentials of the tea extract are roughly similar and the total amount of soluble solids is also roughly similar, and the plural line segments formed by two adjacent oxidation-reduction potentials are approaching levels, and the plural line segments consisting of two adjacent total soluble solids are also approaching levels, which is the same as that in the tea extract The extraction of tea polyphenols and theanine after 40 minutes. From the above, it can be seen that the change trend of the oxidation-reduction potential of the tea extract and the total amount of soluble solids is related to the change trend of the extraction amount of tea polyphenols and theanine in the tea extract. Therefore, the redox potential and soluble The total amount of solids can be used as an indicator of the extraction degree of flavor substances in black tea leaves.

Also, the slope of the line segment formed by the oxidation-reduction potentials of the tea extract at 20 minutes and 40 minutes is -0.4 [that is, (131-138)/(40-20)], and at the same time, the total soluble solids The slope of the line segment formed by the amount of tea is 3.3 [that is, (367-301)/(40-20)], and such a slope just reflects the relative extraction amount of tea polyphenols and theanine in the tea extract. Therefore, the extraction process can meet the slope of the line segment formed by the oxidation-reduction potential at the same monitoring time point from -5 to 0.1 and the slope of the line segment formed by the total amount of soluble solids to be above -2.5 And stop at any time after the monitoring time point when it is less than 3.5.

In addition to using the slope as a judgment to stop the extraction process, the rate of change of the total soluble solids in the tea extract at 50 minutes and 60 minutes showed opposite signs, and at 50 minutes, the rate of change was 5.7%{ That is, [(388-367)/367] × 100%}, and at 60 minutes, the rate of change is -1.0% {ie, [(384-388)/388] × 100%}, and the positive and negative signs start to appear The opposite phenomenon just reflects that the relative extraction amount of tea polyphenols and theanine in the tea extract has reached more than 90%, and the relative extraction amount of at least one of the tea polyphenols and the theanine has reached 95%. % or more, therefore, the extraction process can be stopped at any time after the monitoring time point when the rate of change of the total soluble solids shows a phenomenon of opposite signs.

Table 8 Pattern four Pearson correlation coefficient Tea polyphenols Theanine redox potential -0.954 -0.915 Total Soluble Solids 0.993 0.971

Referring to Table 8, there is indeed a high correlation between the oxidation-reduction potential and the total amount of soluble solids of the tea extract and the extraction amount of tea polyphenols and theanine in the tea extract. Therefore, the oxidation-reduction potential and soluble solids The total amount can indeed be used as an indicator of the degree of extraction of flavor substances in black tea leaves. In addition, compared to the extraction temperature of State 2 at 90°C, State 4 operates at an extraction temperature of 50°C, and the monitoring results are not much different from State 2, which means that the extraction temperature The change does not affect the result of the present invention using the sensing unit to monitor the extraction degree of black tea leaves.

"Establishment of a real-time monitoring method for the extraction degree of green tea leaves"

The real-time monitoring method of the extraction degree of green tea leaves is similar to the real-time monitoring method of black tea leaves in aspect 2, the difference lies in: using green tea leaves (origin: Taiwan; type: Taiwan Tea No. 12), and changing the amount of tea raw materials and extraction treatment conditions, as shown in Table 9.

Table 9 tea raw material type green tea leaves Dosage(kg) 1 water Dosage(kg) 99 Extraction temperature(℃) 70 time (min) 0 10 20 30 40 50 60 Tea polyphenols Extraction amount (μg/mL) 0 624 1082 1268 1309 1329 1356 Relative extraction amount (%) 0 46 79.8 93.5 96.5 98 100 Theanine Extraction amount (μg/mL) 0 104 133 139 135 149 142 Relative extraction amount (%) 0 69.5 89 93.2 90.7 100 94.9 Total soluble solids (ppm) 17 179 240 261 282 291 283 Slope of total soluble solids - 16.2 6.1 2.1 2.1 0.9 -0.8 Change rate of total soluble solids (%) - 952.9 34.1 8.8 8.0 3.2 -2.7 Oxidation-reduction potential (mv) 186 64 54 47 41 42 45 The slope of the redox potential - -12.2 -1.0 -0.7 -0.6 0.1 0.3 Change rate of redox potential (%) - -65.6 -15.6 -13.0 -12.8 2.4 7.1

Referring to Table 9 and Figure 9, from 0 minute to 30 minutes, the extraction amount of tea polyphenols and theanine in the test samples increased with time, and at 30 minutes, the relative extraction amount was More than 90% of tea polyphenols and theanine are extracted from the green tea leaves.

Referring to Figure 9 and Figure 10, at 0 minutes to 30 minutes, the oxidation-reduction potential of the tea extract at each monitoring time point decreases with time, and the total amount of soluble solids increases with time, and the The extraction amount of tea polyphenols and theanine in the tea extract increased with time. It can be seen that the redox potential and the extraction amount of tea polyphenols and theanine showed a negative relationship between 0 minutes and 30 minutes. Correlation, and the total amount of soluble solids was positively correlated with the extraction amount of tea polyphenols and theanine. From the above, it can be seen that the change trend of the oxidation-reduction potential of the tea extract and the total amount of soluble solids is related to the change trend of the extraction amount of tea polyphenols and theanine in the tea extract. Therefore, the redox potential and soluble The total amount of solids can be used as an indicator of the extraction degree of flavor substances in green tea leaves.

Also, the slope of the line segment formed by the oxidation-reduction potentials of the tea extract at 20 minutes and 30 minutes is -0.7 [that is, (47-54)/(30-20)]. At the same time, the soluble solids The slope of the line segment formed by the total amount is 2.1 [that is, (261-240)/(30-20)], and such a slope just reflects the relative extraction amount of tea polyphenols and theanine in the tea extract It has reached more than 90%. Therefore, the extraction treatment can meet the slope of the line segment formed by the redox potential at the same monitoring time point from -5 to 0.1 and the slope of the line segment formed by the total amount of soluble solids to meet -2.5 Stop at any time after the monitoring time point when it is above and less than 3.5.

In addition to using the slope as a judgment to stop the extraction process, the change rates of the redox potentials of the tea extract at 40 minutes and 50 minutes showed opposite signs, and at 40 minutes, the rate of change was -12.8%{ That is, [(41-47)/47] × 100%}, and at 50 minutes, the rate of change is 2.4% {ie, [(42-41)/41] × 100%}, and the opposite sign of sign begins to appear The phenomenon just reflects that the relative extraction amount of tea polyphenols and theanine in the tea extract has reached more than 90%, and the relative extraction amount of at least one of the tea polyphenols and the theanine has reached 95%. Above, therefore, the extraction treatment can be stopped at any time after the monitoring time point when the rate of change of the oxidation-reduction potential exhibits a phenomenon of opposite signs.

Table 10 Pearson correlation coefficient Tea polyphenols Theanine redox potential -0.927 -0.988 Total Soluble Solids 0.989 0.987

Referring to Table 10, there is indeed a high correlation between the oxidation-reduction potential and the total amount of soluble solids of the tea extract and the extraction amount of tea polyphenols and theanine in the tea extract. Therefore, the oxidation-reduction potential and soluble solids The total amount can indeed be used as an indicator of the extraction degree of tea polyphenols and theanine in green tea leaves.

"Establishment of a real-time monitoring method for the extraction degree of oolong tea leaves"

The real-time monitoring method of the extraction degree of oolong tea leaves is similar to the real-time monitoring method of the extraction degree of green tea leaves, the difference is that: use oolong tea leaves (origin: Taiwan; tea source: high mountain oolong tea bags from Lipton Mingxianqing), as shown in Table 11 Show.

Table 11 tea raw material type oolong tea Dosage(kg) 1 water Dosage(kg) 99 Extraction temperature(℃) 70 time (min) 0 20 40 50 60 80 100 120 Tea polyphenols Extraction amount (μg/mL) 0 644 853 953 979 997 1006 1021 Relative extraction amount (%) 0 63.1 83.5 93.3 95.9 97.7 98.5 100 Theanine Extraction amount (μg/mL) 0 210 282 303 308 318 315 313 Relative extraction amount (%) 0 66.1 88.8 95.2 96.8 100 99.2 98.4 Total soluble solids (ppm) 17 162 231 243 246 249 250 252 Slope of total soluble solids - 7.3 3.5 1.2 0.3 0.2 0.1 0.1 Change rate of total soluble solids (%) - 852.9 42.6 5.2 1.2 1.2 0.4 0.8 Oxidation-reduction potential (mv) 186 93 43 41 39 38 39 39 The slope of the redox potential - -4.7 -2.5 -0.2 -0.2 -0.1 0.1 0 Change rate of redox potential (%) - -50.0 -53.8 -4.7 -4.9 -2.6 2.6 0

Referring to Table 11 and Figure 11, from 0 minutes to 50 minutes, the extraction amount of tea polyphenols and theanine in these test samples increased with time, and at 50 minutes, the relative extraction amount was More than 90wt% of tea polyphenols and theanine are extracted from the oolong tea leaves, and after 50 minutes, the extraction amounts of the tea polyphenols and theanine in the tea extracts are similar, making A plurality of line segments formed by two adjacent extraction amounts of tea polyphenols and a plurality of line segments formed by two adjacent extraction amounts of theanine are approach levels.

Referring to Figure 11 and Figure 12, at 0 minutes to 50 minutes, the oxidation-reduction potential of the tea extract at each monitoring time point decreases with time, and the total amount of soluble solids increases with time, while at The extraction amount of tea polyphenols and theanine in the tea extract increases with time, so it can be seen that the redox potential and the extraction amount of tea polyphenols and theanine show a positive relationship between 0 minutes and 50 minutes. Negative correlation, and the total amount of soluble solids was positively correlated with the extraction amount of tea polyphenols and theanine, and after 50 minutes, the oxidation-reduction potentials of the tea extract were roughly similar and the total amount of soluble solids was also roughly similar, and the plural line segments formed by two adjacent oxidation-reduction potentials are approaching levels, and the plural line segments consisting of two adjacent total soluble solids are also approaching levels, which is the same as that in the tea extract The extraction of tea polyphenols and theanine after 50 minutes. From the above, it can be seen that the change trend of the oxidation-reduction potential of the tea extract and the total amount of soluble solids is related to the change trend of the extraction amount of tea polyphenols and theanine in the tea extract. Therefore, the redox potential and soluble The total amount of solids can be used as an indicator of the extraction degree of flavor substances in oolong tea leaves.

Also, the slope of the line segment formed by the oxidation-reduction potentials of the tea extract at 40 minutes and 50 minutes is -0.2 [that is, (41-43)/(50-40)], and at the same time, the total soluble solids The slope of the line segment formed by the amount of tea is 1.2 [that is, (243-231)/(50-40)], and such a slope just reflects the relative extraction amount of tea polyphenols and theanine in the tea extract. Therefore, the extraction process can meet the slope of the line segment formed by the oxidation-reduction potential at the same monitoring time point from -5 to 0.1 and the slope of the line segment formed by the total amount of soluble solids to be above -2.5 And stop at any time after the monitoring time point when it is less than 3.5.

In addition to using the slope as a judgment to stop the extraction process, the change rates of the redox potentials of the tea extract at 80 minutes and 100 minutes showed opposite signs, and at 80 minutes, the rate of change was -2.6%{ That is, [(38-39)/39] × 100%}, and at 100 minutes, the rate of change was 2.6% {ie, [(39-38)/38] × 100%}, and began to show signs of opposite signs The phenomenon just reflects that the relative extraction amount of tea polyphenols and theanine in the tea extract has reached more than 90%, and the relative extraction amount of at least one of the tea polyphenols and the theanine has reached 95%. Above, therefore, the extraction treatment can be stopped at any time after the monitoring time point when the rate of change of the oxidation-reduction potential exhibits a phenomenon of opposite signs.

Table 12 Pearson correlation coefficient Tea polyphenols Theanine redox potential -0.971 -0.928 Total Soluble Solids 0.997 0.985

Referring to Table 12, there is indeed a high correlation between the oxidation-reduction potential and the total amount of soluble solids of the tea extract and the extraction amount of tea polyphenols and theanine in the tea extract. Therefore, the oxidation-reduction potential and soluble solids The total amount can indeed be used as an indicator of the extraction degree of flavor substances in oolong tea leaves.

"Establishment of a real-time monitoring method for the extraction degree of green herbal tea materials"

The real-time monitoring method of the extraction degree of green grass tea materials is similar to the real-time monitoring method of the black tea leaf extraction degree of the second aspect. Grass (origin of origin is Taiwan) and Houttuynia cordata (origin of origin is Taiwan) herbal tea materials, and the amount of tea raw materials and monitoring time are changed, as shown in Table 13.

Table 13 tea raw material type Herbal Tea Ingredients Dosage(kg) 7.5 water Dosage(kg) 92.5 Extraction temperature(℃) 90 time (min) 0 20 40 60 80 100 Tea polyphenols Extraction amount (μg/mL) 200.0 582.4 711.8 776.5 747.1 811.8 Relative extraction amount (%) 24.6 71.7 87.7 95.7 92 100 Theanine Extraction amount (μg/mL) 69.6 450.6 534.2 567.1 394.9 402.5 Relative extraction amount (%) 12.3 79.5 94.2 100 69.6 71 Total soluble solids (ppm) 189 1687 2104 2090 1630 1530 Slope of total soluble solids - 74.9 20.9 -0.7 -23.0 -5.0 Change rate of total soluble solids (%) - 792.6 24.7 -0.7 -22.0 -6.1 Oxidation-reduction potential (mv) 209 173 168 159 157 155 The slope of the redox potential - -1.8 -0.3 -0.5 -0.1 -0.1 Change rate of redox potential (%) - -17.2 -2.9 -5.4 -1.3 -1.3

Referring to Table 13 and Figure 13, from 0 minutes to 60 minutes, the extraction amount of tea polyphenols and theanine in the test samples increased with time, and at 60 minutes, the relative extraction amount was More than 90% of tea polyphenols and theanine are extracted from the herbal tea material.

Referring to Figure 13 and Figure 14, at 0 minutes to 60 minutes, the oxidation-reduction potential of the tea extract at each monitoring time point decreases with time, and the total amount of soluble solids increases with time, and the The extraction amount of tea polyphenols and theanine in the tea extract increased with time. It can be seen that the redox potential and the extraction amount of tea polyphenols and theanine showed a negative relationship between 0 minutes and 60 minutes. Correlation, and the total amount of soluble solids was positively correlated with the extraction amount of tea polyphenols and theanine. From the above, it can be seen that the change trend of the oxidation-reduction potential of the tea extract and the total amount of soluble solids is related to the change trend of the extraction amount of tea polyphenols and theanine in the tea extract. Therefore, the redox potential and soluble The total amount of solids can be used as an indicator of the extraction degree of flavor substances in herbal tea leaves.

Also, the slope of the line segment formed by the oxidation-reduction potentials of the tea extract at 40 minutes and 60 minutes is -0.5 [that is, (159-168)/(60-40)], and at the same time, the total soluble solids The slope of the line segment formed by the amount of tea is -0.7 [that is, (2090-2104)/(60-40)], and such a slope just reflects the relative extraction amount of tea polyphenols and theanine in the tea extract It has reached more than 90%. Therefore, the extraction treatment can meet the slope of the line segment formed by the redox potential at the same monitoring time point from -5 to 0.1 and the slope of the line segment formed by the total amount of soluble solids to meet -2.5 Stop at any time after the monitoring time point when it is above and less than 3.5.

In addition to using the slope as a judgment to stop the extraction process, the rate of change of the total soluble solids of the tea extract at 40 minutes and 60 minutes showed opposite signs, and at 40 minutes, the rate of change was 24.7%{ That is, [(2104-1687)/1687] × 100%}, and at 60 minutes, the rate of change is -0.7% {ie, [(2090-2104)/2104] × 100%}, and the positive and negative signs begin to appear The opposite phenomenon just reflects that the relative extraction amount of tea polyphenols and theanine in the tea extract has reached more than 90%, and the relative extraction amount of at least one of the tea polyphenols and the theanine has reached 95%. % or more, therefore, the extraction process can be stopped at any time after the monitoring time point when the rate of change of the total soluble solids shows a phenomenon of opposite signs.

Table 14 Pearson correlation coefficient Tea polyphenols Theanine redox potential -0.994 -0.994 Total Soluble Solids 0.990 0.998

Referring to Table 14, there is indeed a high correlation between the redox potential and the total amount of soluble solids of the tea extract and the extraction amount of tea polyphenols and theanine in the tea extract. Therefore, the redox potential and soluble solids The total amount can indeed be used as an indicator of the extraction degree of the flavoring substances of the herbal tea material.

To sum up, using the sensing unit to monitor the redox potential and the total amount of soluble solids of the tea extract in real time during the extraction process of the tea raw material, the method for real-time monitoring of the extraction degree of the tea raw material in the present invention does not need to be carried out during the extraction process. During the extraction process, a small amount of tea extract is taken out from the extraction device, and the extraction degree of the tea raw material is confirmed by human tasting or human judgment of color, thereby reducing the error caused by human judgment. In addition, by monitoring the total soluble solids data and redox potential data of the tea extract, the real-time monitoring method of the tea raw material extraction degree of the present invention can directly judge the extraction degree of the tea raw material without being disturbed by the tea raw material, so Really can reach the purpose of the present invention.

But the above-mentioned ones are only embodiments of the present invention, and should not limit the scope of the present invention. All simple equivalent changes and modifications made according to the patent scope of the present invention and the content of the patent specification are still within the scope of the present invention. Within the scope covered by the patent of the present invention.

Other features and effects of the present invention will be clearly presented in the implementation manner with reference to the drawings, wherein: Fig. 1 is a graph illustrating the extraction process of the method for instant monitoring of the extraction degree of black tea leaves of the present invention, the change of the extraction amount of tea polyphenols and theanine in the tea extract; Fig. 2 is a graph illustrating the changes in the total amount of soluble solids and redox potential of the tea extract during the extraction process of the state one; Fig. 3 is a graph illustrating the variation of the extraction amount of tea polyphenols and theanine in the tea extract during the second extraction process of the instant monitoring method for the extraction degree of black tea leaves of the present invention; Fig. 4 is a graph illustrating the changes in the total amount of soluble solids and redox potential of the tea extract during the extraction process of the second aspect; Fig. 5 is a graph illustrating the change of the extraction amount of tea polyphenols and theanine in the tea extract during the extraction process of the third aspect of the instant monitoring method for the extraction degree of black tea leaves of the present invention; Fig. 6 is a graph illustrating the changes in the total amount of soluble solids and redox potential of the tea extract during the extraction process of the third aspect; Fig. 7 is a graph illustrating the changes in the content of tea polyphenols and theanine in the tea extract during the extraction process of the fourth aspect of the instant monitoring method for the extraction degree of black tea leaves of the present invention; Fig. 8 is a graph illustrating the change of the total soluble solids and redox potential of the tea extract during the extraction process of the fourth aspect; Fig. 9 is a graph illustrating the changes in the extraction amount of tea polyphenols and theanine in the tea extract during the extraction process of the instant monitoring method for the extraction degree of green tea leaves of the present invention; Figure 10 is a graph illustrating the changes in the total amount of soluble solids and redox potential of the tea extract during the extraction process of the instant monitoring method for the extraction degree of green tea leaves; Fig. 11 is a graph illustrating the changes in the extraction amount of tea polyphenols and theanine in the tea extract during the extraction process of the instant monitoring method for the extraction degree of oolong tea leaves of the present invention; Figure 12 is a graph illustrating the changes in the total soluble solids and redox potential of the tea extract during the extraction process of the method for real-time monitoring of the extraction degree of oolong tea leaves; Fig. 13 is a graph illustrating the changes in the extraction amount of tea polyphenols and theanine in the tea extract during the extraction process of the instant monitoring method for the extraction degree of herbal tea materials of the present invention; and Fig. 14 is a graph illustrating the change of total soluble solids and redox potential of the tea extract during the extraction process of the method for real-time monitoring of the extraction degree of herbal tea materials.

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Claims (3)

A real-time monitoring method for the extraction degree of tea raw materials, comprising the following steps: The raw material components including water and tea raw materials are placed in an extraction device including a sensing unit for extraction treatment to obtain a tea extract, wherein the tea raw materials are selected from black tea leaves, green tea leaves, oolong tea leaves or Herbal tea ingredients containing grass jelly, peppermint, xianfengcao and houttuynia cordata; and During the extraction process, use the sensing unit to monitor the tea extract over time to obtain the total amount of soluble solids at different times and the redox potential at different times, and when one of the following conditions is met , then stop the extraction process at any time after the monitoring time point of the condition, Condition 1 is that the slope of the line segment formed by the total amount of soluble solids at two adjacent monitoring time points ranges from -2.5 to less than 3.5 and the slope of the line segment formed by the oxidation-reduction potentials at the two adjacent monitoring time points The slope ranges from -5 to -0.1; The second condition is that the positive and negative signs of the rate of change of the total amount of soluble solids at two adjacent monitoring time points are opposite; The third condition is that the positive and negative signs of the change rates of the redox potentials at two adjacent monitoring time points are opposite. The real-time monitoring method for the extraction degree of tea raw materials as described in Claim 1, wherein, based on the total amount of the raw material components being 100 kg, the amount of the tea raw materials ranges from 1 kg to 7.5 kg. The method for real-time monitoring of the extraction degree of tea raw materials as described in Claim 1, wherein the temperature range of the extraction treatment is 50°C to 90°C.

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