TWI774556B - A real-time monitoring method for the extraction degree of tea raw materials - Google Patents

Abstract

A real-time monitoring method for the extraction degree of tea raw materials, comprising: subjecting raw material components including tea raw materials to extraction processing to obtain a tea extract; Total soluble solids and redox potential at different times. When one of the following conditions is met, the extraction process is 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 at the same monitoring time point 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; (2) the sign of the change rate of the total amount of soluble solids at two adjacent monitoring time points is opposite; and (3) the difference between the two adjacent monitoring time points The sign of the rate of change of the redox potential is opposite.

Description

A real-time monitoring method for the extraction degree of tea raw materials

The present 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 production process of 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 the testers can taste the tea soup and observe the color of the tea soup to judge the degree of extraction of the tea leaves. Such an artificial judgment method has no scientific standard, and different testers have different perceptions of the tea taste of tea soup. Therefore, the above method of judging the extraction degree of tea leaves not only requires additional sampling for analysis, but also causes problems in the manufacturing process. Inconvenience, and the tea soup obtained by this method has the problem of uneven quality.

On the other hand, in order to accurately judge the degree of extraction of tea leaves, the tea soup is currently monitored online by using an optical monitoring method. However, during the online monitoring process, the tea leaves still exist in the tea soup, so , the optical monitoring method is easily affected by the presence of the tea leaves and affects the monitoring results.

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

Therefore, the instant monitoring method of the extraction degree of the tea raw material of the present invention comprises the following steps: The raw material components comprising water and tea raw materials are placed in an extraction device comprising a sensing unit for extraction processing 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 celery, mint, xianfengcao and houttuynia cordata; and During the extraction process, use the sensing unit to monitor the tea extract chronologically 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 is -2.5 or more and less than 3.5 and the line segment formed by the redox potentials at the two adjacent monitoring time points. The slope ranges from -5 to -0.1; Condition 2 is that the sign of the rate of change of the total soluble solids at two adjacent monitoring time points is opposite; and Condition 3 is that the sign of the change rates of the redox potentials at two adjacent monitoring time points is opposite.

The effect of the present invention is that the tea extract liquid 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 extracted from the tea raw material during the extraction process. A little tea extract is taken out from the extraction device, and the degree of extraction of the tea raw material is confirmed by human tasting or human judgment of color, thereby reducing errors caused by human judgment. In addition, by monitoring the total soluble solid 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.

The method for monitoring the extraction degree of tea raw materials according to the present invention comprises: using a sensing unit to monitor the extraction degree of flavor substances of the tea raw materials during the extraction process of the raw material components including water and tea raw materials placed in an extraction device. The taste substance is, for example, tea polyphenols that provide astringency or theanine that provides sweetness. In some embodiments of the present invention, the taste substances are tea polyphenols and theanine. The raw material components, the sensing unit, and the 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 tree, Taicha No. 8, Taicha No. 18, and the like. The green tea leaves include, for example, tea leaves from Qingxin orange tea tree or Qingxin oolong tea tree through Biluochun process, tea leaves from Chinese Longjing tea tree, Taicha No. 12, and the like. The oolong tea leaves are, for example, the tea leaves of the Qingxin oolong tea tree or the tea leaves of Taicha No. 12 obtained by the method of making tea, the tea leaves harvested from the oolong tea trees planted at an altitude of 1000 meters or more, 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 fairy grass is harvested from September to October every year and is produced in Taiwan's Hsinchu Kansai, Miaoli Tongluo, Taoyuan Xinwu, Hualien Fenglin, and the like. The mint is, for example, spearmint. The Xianfengcao is, for example, Dahua Xianfengcao. For example, the Houttuynia cordata is produced in Taiwan and harvested from June to July and September to October every year.

In some embodiments of the present invention, in order to obtain a better extraction amount of taste-presenting substances, in order to achieve an appropriate extraction benefit, based on the total amount of the raw material components being 100 kg, the amount of the tea raw material is in the range of 1kg to 7.5kg.

"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 redox potential. In some embodiments of the present invention, the sensing unit includes a total amount of soluble solids sensor and a redox 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"

Aspect One The dosage of black tea leaves is 7.5wt%

The raw material components containing 92.5 kg of water and 7.5 kg of black tea leaves (origin: Taiwan; type: tea leaves of the small-leaf species tea tree) were placed in a total soluble solids sensor (brand: SUNTEX; model: SC-110) and redox potential sensor (brand: JENCO; model: 6010M), and the extraction process was carried out at 90°C, wherein during the extraction process, the extraction process was timed at 0 minutes, At 10 minutes, 20 minutes, 30 minutes, 40 minutes, 60 minutes, 90 minutes, 120 minutes and 180 minutes, take out a little tea extract from the extraction device as a test sample, and use an ultraviolet-visible light spectrometer (brand name). : Merck; model: Spectroquant ^® Pharo 300) to analyze the extraction amount of tea polyphenols and theanine acid in each test sample, and use the test sample with the highest extraction amount of tea polyphenols in these test samples. The extraction amount is 100%, and the extraction amount of theanine in the test sample with the maximum extraction amount of theanine in these test samples is 100%, convert the tea polyphenols and tea in the remaining test samples. The relative extraction amount of amino acids, the results are shown in Table 1, and according to the results in Table 1, a graph of the extraction amount of tea polyphenols and theanine acid and extraction time is drawn, as shown in Figure 1.

At the same time, during the extraction process, the total soluble solids sensor and the redox potential sensor also monitor the tea extract in time, and provide the tea extract at each monitoring point. The total amount of soluble solids and redox potential, the results are shown in Table 1, and according to the results in Table 1, the curve diagram of the total amount of soluble solids, redox potential and extraction time is drawn, as shown in Figure 2.

Table 1 form 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 Redox 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 Figure 1, from 0 minutes to 40 minutes, the extraction amount of tea polyphenols and theanine acid in these test samples increased with time, and at 40 minutes, there was a relative The tea polyphenols and theanine acids with an extraction amount of more than 90% are extracted from the black tea leaves, and after 40 minutes, the extraction amounts of the tea polyphenols and the theanine acids in the tea extracts are close to each other, so that the plurality of line segments formed by the extraction amount of two adjacent tea polyphenols and the plurality of line segments formed by the extraction amount of two adjacent theanine acids are close to the level.

Referring to Figure 1 and Figure 2, from 0 minutes to 40 minutes, the redox potential of the tea extract at each monitoring time point decreased with time, and the total amount of soluble solids increased with time, and the The extraction amount of tea polyphenols and theanine in the tea extract increases with time. It can be seen that from 0 minutes to 40 minutes, the redox potential and the extraction amount of tea polyphenols and theanine are negative. correlation, and the total amount of soluble solids was positively correlated with the extraction amount of tea polyphenols and theanine, and after 40 minutes, the redox potentials of the tea extract were approximately similar and the total amount of soluble solids was also Roughly similar, and the line segments composed of two adjacent redox potentials are close to the level, and the line segments composed of the total amount of two adjacent soluble solids are also close to the level, which is the same as that in the tea extract. The extraction amount of tea polyphenols and theanine after 40 minutes. It can be seen from the above that the change trend of the redox potential and the total amount of soluble solids of the tea extract is related to the change trend of the extraction amount of tea polyphenols and theanine in the tea extract. Therefore, the redox potential is related to the solubility. The total amount of solids can be used as an indicator of the degree of extraction of flavor substances in black tea leaves.

Also, the slope of the line segment formed by the redox potentials of the tea extract at 30 minutes and 40 minutes is -0.6 [ie, (155-161)/(40-30)], and at the same time, the total soluble solids The slope of the line segment formed by the amount of the It has reached more than 90%. Therefore, the extraction process can satisfy the slope of the line segment formed by the redox potentials 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 satisfy -2.5 It stops at any time after the monitoring time point when it is more than 3.5.

In addition to the permeation slope as the judgment for stopping the extraction process, the change rates of the total soluble solids in the tea extract at 30 minutes and 40 minutes have opposite signs, and at 30 minutes, the change rate is 4.2%{ i.e., [(1024-982)/982]×100%}, and at 40 minutes the rate of change is -2.3% {i.e., [(1000-1024)/1024]×100%}, and the sign starts 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 theanine has reached 95%. % or more, therefore, the extraction process can be stopped at any time after the monitoring time point at which the rate of change of the total amount of soluble solids exhibits a phenomenon of opposite sign.

In order to confirm the 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, the Pearson Correlation Coefficient was calculated using the CORREL function. , and the results are shown in Table 2.

Table 2 form 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 redox potential and the total amount of soluble solids of the tea extract and the extracted amount of tea polyphenols and theanine in the tea extract. Therefore, redox potential and total soluble solids can indeed be used as indicators of the degree of extraction of flavor substances from black tea leaves.

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

The real-time monitoring method for the extraction degree of black tea leaves in the second aspect is similar to the real-time monitoring method for the extraction degree of black tea in the first aspect, except that the dosage ratio of black tea leaves and the monitoring time are changed, as shown in Table 3.

table 3 form 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 Redox 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 FIG. 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 aspect, so it will not be repeated.

Referring to FIG. 3 and FIG. 4 , the relationship between the total 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 the aspect, so it is not Repeat. In the second aspect, the slope of the line segment formed by the redox 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 rates of change of the redox potentials of the tea extract have opposite signs, and at 30 minutes, the rate of change is -112.9% {ie, {[(-9)-70]/70}×100% }, while at 40 minutes, the rate of change was 522.2% {ie, {[-56-(-9)]/(-9)}×100%}.

Table 4 form 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 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 the soluble solids are highly correlated. 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 amount of black tea leaves used in the first aspect of 7.5 wt %, the second aspect operates under the condition that the amount of black tea leaves used in the second aspect is 2.5 wt %, and the monitoring results are not too different from this aspect. The difference is large, 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.

Aspect 3 The dosage of black tea leaves is 25kg, and the dosage of water is 975kg

The real-time monitoring method for the extraction degree of black tea leaves in the third aspect is similar to the real-time monitoring method for the extraction degree of black tea in the second aspect. A digital sensor for water quality monitoring (brand: HACH; model: SC200TM) that measures total soluble solids and redox potential.

table 5 Mode 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 Redox 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, at 0 minutes to 30 minutes, the extraction amounts of tea polyphenols and theanine in these detection samples increased with time, and at 30 minutes, the relative extraction amounts were 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 extract are similar, so that A plurality of line segments composed of two adjacent extraction amounts of tea polyphenols and a plurality of line segments composed of two adjacent extraction amounts of theanine are close to the level.

Referring to Figure 5 and Figure 6, from 0 minutes to 30 minutes, the redox potential of the tea extract at each monitoring time point decreased with time, and the total amount of soluble solids increased with time. The extraction amount of tea polyphenols and theanine in the tea extract increases with time. It can be seen that from 0 minutes to 30 minutes, the redox potential and the extraction amount of tea polyphenols and theanine are negative. The total amount of soluble solids was positively correlated with the extraction amount of tea polyphenols and theanine. It can be seen from the above that the change trend of the redox potential and the total amount of soluble solids of the tea extract is related to the change trend of the extraction amount of tea polyphenols and theanine in the tea extract. Therefore, the redox potential is related to the solubility. The total amount of solids can be used as an indicator of the degree of extraction of flavor substances in black tea leaves.

Also, the slope of the line segment formed by the redox potentials of the tea extract at 20 minutes and 30 minutes is -3.5 {ie, [-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 [ie, (766-742)/(40-30)], and such a slope just reflects the tea polyphenols and theanine in the tea extract. The relative extraction amount has reached more than 90%. Therefore, the extraction treatment can satisfy the slope of the line segment formed by the redox potentials at the same monitoring time point from -5 to 0.1 and 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 the permeation slope as the judgment for stopping the extraction process, the change rates of the redox potentials of the tea extract at 20 minutes and 30 minutes have opposite signs, and at 20 minutes, the change rate is -238.1%{ That is, {[(-87)-63]/63}×100%}, and at 30 minutes, the rate of change is 40.2% {that is, {[-122-(-87)]/(-87)}× 100%}, and the phenomenon that the positive and negative signs are reversed at the beginning 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 the theanine are at least 100% in the theanine. The relative extraction amount of one has reached more than 95%, so the extraction process can be stopped at any time after the monitoring time point when the rates of change of the redox potentials exhibit opposite signs.

Table 6 Mode 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 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 are highly correlated. 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 run of Aspect 2, Aspect 3 operates under the conditions of mass production, and the monitoring results are not much different from Aspect 2, which means that the The amount of black tea leaves and water is enlarged to the conditions of mass production, and it is also suitable for monitoring the extraction degree of black tea leaves through the sensing unit.

Aspect Four The extraction temperature is 50℃

The real-time monitoring method for the extraction degree of black tea leaves in the fourth aspect is similar to the real-time monitoring method for the extraction degree of the black tea in the second aspect, except that the extraction temperature is changed, as shown in Table 7.

Table 7 Form 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 Redox 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, at 0 minutes to 40 minutes, the extraction amounts of tea polyphenols and theanine in these detection samples increased with time, and at 40 minutes, the relative extraction amounts were 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 acids in the tea extracts are similar, so that the line segments formed by the extraction amounts of two adjacent tea polyphenols and the plurality of lines consisting of two phases The line segment formed by the extraction amount of adjacent theanine is close to the level.

Referring to Figure 7 and Figure 8, from 0 minutes to 40 minutes, the redox potential of the tea extract at each monitoring time point decreased with time, and the total amount of soluble solids increased with time, and the The extraction amount of tea polyphenols and theanine in the tea extract increases with time. It can be seen that from 0 minutes to 40 minutes, the redox potential and the extraction amount of tea polyphenols and theanine are negative. correlation, and the total amount of soluble solids was positively correlated with the extraction amount of tea polyphenols and theanine, and after 40 minutes, the redox potentials of the tea extract were approximately similar and the total amount of soluble solids was also Roughly similar, and the line segments composed of two adjacent redox potentials are close to the level, and the line segments composed of the total amount of two adjacent soluble solids are also close to the level, which is the same as that in the tea extract. The extraction amount of tea polyphenols and theanine after 40 minutes. It can be seen from the above that the change trend of the redox potential and the total amount of soluble solids of the tea extract is related to the change trend of the extraction amount of tea polyphenols and theanine in the tea extract. Therefore, the redox potential is related to the solubility. The total amount of solids can be used as an indicator of the degree of extraction of flavor substances in black tea leaves.

Also, the slope of the line segment formed by the redox potentials of the tea extract at 20 minutes and 40 minutes is -0.4 [ie, (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 extract 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. Reach more than 90%, therefore, the extraction process can meet the slope of the line segment formed by these redox potentials 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 satisfies -2.5 or more And stop at any time after the monitoring time point when it is less than 3.5.

In addition to the permeation slope as the judgment for stopping the extraction process, the change rates of the total soluble solids in the tea extract at 50 minutes and 60 minutes have opposite signs, and at 50 minutes, the change rate is 5.7%{ i.e., [(388-367)/367]×100%}, and at 60 minutes the rate of change is -1.0% {i.e., [(384-388)/388]×100%}, and the sign starts 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 theanine has reached 95%. % or more, therefore, the extraction process can be stopped at any time after the monitoring time point at which the rate of change of the total amount of soluble solids exhibits a phenomenon of opposite sign.

Table 8 Form 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 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 the soluble solids are highly correlated. 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 extraction temperature of Aspect 2, which is 90°C, Aspect 4 operates at an extraction temperature of 50°C, and there is not much difference between the monitoring results and Aspect 2, which indicates 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 the second aspect, the difference is: the use of green tea leaves (origin: Taiwan; type: Taicha No. 12), as well as 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 Redox 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, at 0 minutes to 30 minutes, the extraction amounts of tea polyphenols and theanine in these detection samples increased with time, and at 30 minutes, the relative extraction amounts were More than 90% of tea polyphenols and theanine are extracted from the green tea leaves.

Referring to Figure 9 and Figure 10, from 0 minutes to 30 minutes, the redox potential of the tea extract at each monitoring time point decreased with time, and the total amount of soluble solids increased with time, and the The extraction amount of tea polyphenols and theanine in the tea extract increases with time. It can be seen that from 0 minutes to 30 minutes, the redox potential and the extraction amount of tea polyphenols and theanine are negative. The total amount of soluble solids was positively correlated with the extraction amount of tea polyphenols and theanine. It can be seen from the above that the change trend of the redox potential and the total amount of soluble solids of the tea extract is related to the change trend of the extraction amount of tea polyphenols and theanine in the tea extract. Therefore, the redox potential is related to the solubility. The total amount of solids can be used as an indicator of the degree of extraction of flavor substances in green tea leaves.

Also, the slope of the line segment formed by the redox potentials of the tea extract at 20 minutes and 30 minutes is -0.7 [ie, (47-54)/(30-20)], and at the same time, the soluble solids The slope of the line segment formed by the total amount is 2.1 [ie, (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 process can satisfy the slope of the line segment formed by the redox potentials 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 satisfy -2.5 It stops at any time after the monitoring time point when it is more than 3.5.

In addition to the permeation slope as the judgment for stopping the extraction process, the change rates of the redox potentials of the tea extract at 40 minutes and 50 minutes have opposite signs, and at 40 minutes, the change rate is -12.8%{ i.e., [(41-47)/47]×100%}, and at 50 minutes the rate of change is 2.4% {i.e., [(42-41)/41]×100%}, which starts to show opposite signs The phenomenon just reflects that the relative extraction amount of tea polyphenols and theanine acid 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 acid has reached 95%. As above, therefore, the extraction process can be stopped at any time after the monitoring time point at which the rates of change of the redox potentials exhibit a phenomenon of opposite sign.

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 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 are highly correlated. The total amount can indeed be used as an indicator of the degree of extraction of tea polyphenols and theanine in green tea leaves.

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

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

Table 11 tea raw material type oolong tea leaves 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 Redox 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 FIG. 11 , at 0 minutes to 50 minutes, the extraction amounts of tea polyphenols and theanine in these test samples increased with time, and at 50 minutes, the relative extraction amounts were More than 90wt% of tea polyphenols and theanine are extracted from the oolong tea leaves, and after 50 minutes, the extraction amounts of these tea polyphenols and the theanine in these tea extracts are similar, so that A plurality of line segments composed of two adjacent extraction amounts of tea polyphenols and a plurality of line segments composed of two adjacent extraction amounts of theanine are close to the level.

Referring to Figure 11 and Figure 12, from 0 minutes to 50 minutes, the redox potential of the tea extract at each monitoring time point decreased with time, and the total amount of soluble solids increased with time. The extraction amount of tea polyphenols and theanine in the tea extract increases with time. It can be seen that from 0 minutes to 50 minutes, the redox potential and the extraction amount of tea polyphenols and theanine show Negative correlation, and the total amount of soluble solids and the extraction amount of tea polyphenols and theanine acid showed a positive correlation, and after 50 minutes, the redox potentials of the tea extract were roughly similar and the total amount of soluble solids was also the same. Roughly similar, and the line segments composed of two adjacent redox potentials are close to the level, and the line segments composed of the total amount of two adjacent soluble solids are also close to the level, which is the same as that in the tea extract. The extraction amount of tea polyphenols and theanine after 50 minutes. It can be seen from the above that the change trend of the redox potential and the total amount of soluble solids of the tea extract is related to the change trend of the extraction amount of tea polyphenols and theanine in the tea extract. Therefore, the redox potential is related to the solubility. 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 redox potentials of the tea extract at 40 minutes and 50 minutes is -0.2 [ie, (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. Reach more than 90%, therefore, the extraction process can meet the slope of the line segment formed by these redox potentials 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 satisfies -2.5 or more And stop at any time after the monitoring time point when it is less than 3.5.

In addition to the permeation slope as the judgment for stopping the extraction process, the change rates of the redox potentials of the tea extract at 80 minutes and 100 minutes have opposite signs, and at 80 minutes, the change rate is -2.6%{ i.e., [(38-39)/39]×100%}, and at 100 minutes the rate of change is 2.6% {i.e., [(39-38)/38]×100%}, which starts to show opposite signs The phenomenon just reflects that the relative extraction amount of tea polyphenols and theanine acid 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 acid has reached 95%. As above, therefore, the extraction process can be stopped at any time after the monitoring time point at which the rates of change of the redox potentials exhibit a phenomenon of opposite sign.

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 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 are highly correlated. The total amount can indeed be used as an indicator of the degree of extraction of flavor substances in oolong tea leaves.

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

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

Table 13 tea raw material type herbal tea material 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 Redox 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 Fig. 13, from 0 minutes to 60 minutes, the extraction amounts of tea polyphenols and theanine in these test samples increased with time, and at 60 minutes, the relative extraction amounts were More than 90% of tea polyphenols and theanine are extracted from the herbal tea material.

Referring to Figure 13 and Figure 14, from 0 minutes to 60 minutes, the redox potential of the tea extract at each monitoring time point decreased with time, and the total amount of soluble solids increased with time. The extraction amount of tea polyphenols and theanine in the tea extract increases with time. It can be seen that from 0 minutes to 60 minutes, the redox potential and the extraction amount of tea polyphenols and theanine are negative. The total amount of soluble solids was positively correlated with the extraction amount of tea polyphenols and theanine. It can be seen from the above that the change trend of the redox potential and the total amount of soluble solids of the tea extract is related to the change trend of the extraction amount of tea polyphenols and theanine in the tea extract. Therefore, the redox potential is related to the solubility. 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 redox potentials of the tea extract at 40 minutes and 60 minutes is -0.5 [ie, (159-168)/(60-40)], and at the same time, the total soluble solids The slope of the line segment constituted by the amount of the It has reached more than 90%. Therefore, the extraction process can satisfy the slope of the line segment formed by the redox potentials 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 satisfy -2.5 It stops at any time after the monitoring time point when it is more than 3.5.

In addition to the permeation slope as the judgment for stopping the extraction process, the change rates of the total soluble solids of the tea extract at 40 minutes and 60 minutes have opposite signs, and at 40 minutes, the change rate is 24.7%{ i.e., [(2104-1687)/1687]×100%}, and at 60 minutes, the rate of change is -0.7% {i.e., [(2090-2104)/2104]×100%}, and the sign starts 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 theanine has reached 95%. % or more, therefore, the extraction process can be stopped at any time after the monitoring time point at which the rate of change of the total amount of soluble solids exhibits a phenomenon of opposite sign.

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 are highly correlated. The total amount can indeed be used as an indicator of the extraction degree of the flavor substances of the herbal tea material.

To sum up, using the sensing unit to monitor the redox potential and total soluble solids of the tea extract in real time during the extraction process of the tea raw material, the real-time monitoring method for the extraction degree of the tea raw material of the present invention does not need to perform the extraction process. During the extraction process, a little 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 amount of soluble solids data and redox potential data of the tea extract, the real-time monitoring method for the extraction degree of the tea raw material of the present invention can directly judge the extraction degree of the tea raw material without being disturbed by the tea raw material. Therefore, It can indeed achieve the purpose of the present invention.

However, the above are only examples of the present invention, and should not limit the scope of implementation of the present invention. Any simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the contents of the patent specification are still included in the scope of the present invention. within the scope of the invention patent.

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, wherein: Fig. 1 is a graph, in the extraction treatment process of the aspect 1 of the instant monitoring method for the extraction degree of the black tea tea leaf of the present invention that illustrates, the extraction quantity change of the tea polyphenols and theanine in the tea extract liquid; FIG. 2 is a graph illustrating changes in the total amount of soluble solids and the redox potential of the tea extract during the extraction process of the aspect 1; 3 is a graph illustrating changes in the extraction amounts of tea polyphenols and theanine in the tea extract during the extraction process of aspect 2 of the instant monitoring method for the extraction degree of black tea tea leaves of the present invention; 4 is a graph illustrating changes in the total amount of soluble solids and the redox potential of the tea extract during the extraction process of the second aspect; 5 is a graph illustrating changes in the extraction amounts of tea polyphenols and theanine in the tea extract during the extraction treatment process of aspect 3 of the instant monitoring method for the extraction degree of black tea tea leaves of the present invention; 6 is a graph illustrating changes in the total amount of soluble solids and the redox potential of the tea extract during the extraction process of the third aspect; 7 is a graph illustrating changes in the content of tea polyphenols and theanine in the tea extract during the extraction process of aspect four of the instant monitoring method for the extraction degree of black tea tea leaves of the present invention; 8 is a graph illustrating changes in the total amount of soluble solids and the redox potential of the tea extract during the extraction process of the fourth aspect; Fig. 9 is a graph illustrating the variation of 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 tea leaves of the present invention; 10 is a graph illustrating changes in the total amount of soluble solids and redox potential of the tea extract during the extraction process of the method for instant monitoring of the extraction degree of green tea tea leaves; 11 is a graph illustrating the variation of 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 tea leaves of the present invention; 12 is a graph illustrating changes in the total amount of soluble solids and redox potential of the tea extract during the extraction process of the method for instant monitoring of the extraction degree of oolong tea leaves; 13 is a graph illustrating the change 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 the herbal tea material of the present invention; and 14 is a graph illustrating the changes in the total amount of soluble solids and the 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 comprising water and tea raw materials are placed in an extraction device comprising a sensing unit for extraction processing 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 celery, mint, xianfengcao and houttuynia cordata; and During the extraction process, use the sensing unit to monitor the tea extract chronologically 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 is -2.5 or more and less than 3.5 and the line segment formed by the redox potentials at the two adjacent monitoring time points. The slope ranges from -5 to -0.1; The second condition is that the sign of the change rate of the total amount of soluble solids at two adjacent monitoring time points is opposite; Condition 3 is that the sign of the change rates of the redox potentials at two adjacent monitoring time points is opposite. The real-time monitoring method for the extraction degree of tea raw materials according to claim 1, wherein, based on the total amount of the raw material components being 100 kilograms, the amount of the tea raw materials ranges from 1 kilogram to 7.5 kilograms. The real-time monitoring method for the extraction degree of tea raw materials according to claim 1, wherein the temperature range of the extraction treatment is 50°C to 90°C.

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