A method for evaluating the quality of rolled tea and matcha

Abstract

This invention discloses a standardized evaluation method for the quality of tencha / matcha, belonging to the field of food quality evaluation technology. The method includes the following steps: First, standardized control of the evaluation environment, equipment, personnel, and water used for evaluation is achieved. Then, samples are prepared using corresponding standardized methods based on the different evaluation objects. Next, a dual-dimensional framework of appearance and internal quality is adopted, setting six core evaluation indicators and using a 5-level 100-point scale for quantitative scoring. Then, based on the sample quality characteristics, the basic quantitative score is adjusted using preset positive and negative deduction items to calculate the final evaluation score. Finally, the quality grade is determined based on the final evaluation score, completing the entire evaluation process. This invention addresses the unique quality requirements of tencha / matcha by using a dual-dimensional framework of appearance and internal quality to quantitatively score tencha / matcha and adding dynamic score adjustment, thereby achieving quality evaluation and grading of tencha / matcha.

Description

Technical Field

[0001] This invention belongs to the field of food quality evaluation technology, specifically relating to a standardized evaluation method for the quality of tencha-matcha. Background Technology

[0002] Matcha is made from the tender buds and leaves of tea trees grown under shade, processed through steaming and drying to produce tencha, which is then ground into ultrafine green tea powder. It is a core ingredient in new-style tea drinks, baked goods, and functional foods. As the sole raw material for matcha, the quality of tencha directly determines the upper limit of the final matcha product's quality. Both tencha and matcha, due to their 20-30 day shade cultivation process, develop core quality characteristics that distinguish them from ordinary green tea—extremely high requirements for color, freshness, and body. Traditional ordinary green tea uses five evaluation indicators—appearance, liquor color, aroma, taste, and infused leaf—with weights evenly distributed, failing to highlight the core requirements of tencha / matcha for color, freshness, and body. Furthermore, the brewing method of steeping at 100℃ boiling water for 5 minutes leads to excessive decomposition of the fresh substances in tencha / matcha, failing to truly reflect its quality characteristics. Therefore, there is an urgent need to design a standardized evaluation method for tencha-matcha quality to meet the specific evaluation needs of tencha and matcha. Summary of the Invention

[0003] The embodiments of this application provide a standardized evaluation method for the quality of tencha and matcha to adapt to the specific evaluation needs of tencha and matcha. To achieve the above objective, this application adopts the following technical solution: A standardized evaluation method for tencha and matcha quality includes the following core steps: First, standardize the evaluation environment, evaluation tools, evaluation personnel, and evaluation water, ensuring that the control requirements comply with category-specific optimization rules based on the corresponding national standards; then, prepare the evaluation samples using corresponding standardized methods according to the different evaluation objects; when the evaluation object is tencha, brew the tea soup and tea leaf samples with boiling water at 100℃ for 3 minutes; when the evaluation object is matcha, prepare the tea soup samples using a method of cold water sampling + hot water volume adjustment; next, adopt a dual-dimensional framework of appearance and internal quality, setting 6 core evaluation indicators, and using a 5-level 100-point scoring system for quantitative evaluation; the fixed weights of the 6 core evaluation indicators are: 25 points for the 2 indicators in the appearance dimension and 75 points for the 4 indicators in the internal quality dimension; wherein, the 2 indicators in the appearance dimension... The indicators are adjusted according to the evaluation object. When the evaluation object is tencha, the two indicators are dry tea evaluation and leaf residue evaluation, with weights of 10 and 15 points respectively. When the evaluation object is matcha, the two indicators are color evaluation and particle fineness evaluation, with weights of 15 and 10 points respectively. The four indicators of internal quality are fixed items: liquor color evaluation (10 points), aroma evaluation (15 points), body evaluation (25 points), and freshness evaluation (25 points). Then, based on the sample quality characteristics, the basic quantitative score is adjusted through preset positive bonus items and negative deduction items to calculate the final evaluation score of the sample. The preset rules include positive bonus items related to color and aroma, and negative deduction items related to impurities, particle texture, liquor brightness, and bitterness. Finally, the quality grade is divided based on the final evaluation score to complete the evaluation process.

[0004] As can be seen from the above technical solution, the present invention has the following beneficial effects: This invention addresses the unique quality requirements of tencha / matcha by employing a dual-dimensional framework of appearance and internal quality to quantitatively score tencha / matcha. Based on this framework, dynamic scoring adjustments are added to meet the specific needs of tencha / matcha, thereby achieving quality assessment and grading of tencha / matcha.

[0005] This invention, based on the existing exclusive evaluation method for tencha / matcha, adds a flavor feature matrix with aroma type as the horizontal axis and taste characteristics as the vertical axis, and establishes a dual identification system of grade-primary aroma + secondary aroma-taste type, thus completing the standardized characterization of the flavor features of tencha / matcha products and solving the industry shortcoming of traditional evaluation that "only grades but does not distinguish flavor".

[0006] Based on the proprietary evaluation method for tencha / matcha, this invention makes the final quality rating of tencha / matcha more objective, reasonable and accurate by adding scoring rules and calculation methods when there are more than 5 evaluators.

[0007] Based on the proprietary evaluation method for tencha / matcha, this invention adds a verification step for the evaluation results. The samples obtained by the evaluators are compared with existing known standard samples of the same grade to further adjust the rationality and accuracy of the scoring. This ensures that the results obtained by the final evaluation method are consistent with the results recognized by the market, thus further improving the proprietary evaluation method for tencha / matcha. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the entire review process for this invention; Figure 2 This is a schematic diagram illustrating the standard color of the ground tea in this invention; Figure 3 This is a schematic diagram illustrating the standard impurity level of tea grinding in this invention; Figure 4 This is a schematic diagram illustrating the standard gloss level of the ground tea in this invention. Figure 5 This is a schematic diagram illustrating the standard color of matcha in this invention; Figure 6 This is a schematic diagram of the flavor feature matrix of the present invention. Detailed Implementation

[0009] The terms "first," "second," and "third," etc., used in this application specification, claims, and drawings are used to distinguish different objects, not to define a specific order.

[0010] In the embodiments of this application, the words "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the words "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0011] See attached document Figure 1-6 As shown, this invention provides a standardized evaluation method for the quality of tencha and matcha, specifically for grading the quality of tencha and matcha; the method is as follows: See attached document Figure 1 It can be seen that the quality evaluation method for tencha is as follows: S1. Standardized pre-review preparations: The evaluation environment meets the requirements of GB / T18797-2012. The ambient temperature is controlled at 20-25℃, the relative humidity is controlled at 50-60%, the light is natural light from the north or standard white light, the color temperature is 5500K±500K, there is no odor, no direct light, no noise interference, and the noise here is ≤50dB. Evaluation equipment includes: a white porcelain evaluation bowl conforming to the neutral color requirements of GB / T15608-2006, with N≥9.5, a bowl height of 60mm, an outer diameter of 100mm at the top, a capacity of 200ml, and a bowl wall thickness of 3±0.5mm; an electronic balance with a sensitivity of 0.1g and an accuracy class of III; a food-grade stainless steel kettle made of 304 stainless steel; a timer with an accuracy to the second, requiring an error of ≤1 second / minute; a clean and odorless porcelain teaspoon with a capacity of 5ml±0.5ml; and a black stainless steel tea evaluation tray measuring 30cm×20cm×5cm. Evaluators: Must hold a National Vocational Qualification Certificate for Tea Taster (intermediate level or above); a valid Health Certificate for Food Industry Personnel; uncorrected or corrected visual acuity of 5.0 or above, and no color blindness or color weakness; must change into clean work clothes and clean hands with unscented hand sanitizer before evaluation; must not use cosmetics, smoke, or eat during the entire evaluation process; evaluation intervals must be ≥10 minutes to avoid sensory fatigue. The water used for the assessment meets the requirements of GB 5749-2022 "Standards for Drinking Water Quality". The water temperature is controlled at 100℃±2℃. The water quality and temperature of the same batch of assessment water are completely consistent, with no odor or turbidity. The above standardized control requirements conform to the category-specific optimization rules based on the corresponding national standards; S2. Preparation of Standardized Tencha Samples: Take 3.0g of a representative tencha sample, accurate to 0.1g, and place it in the stainless steel filter inside the tasting bowl. The filter has a pore size of 0.1mm. Use boiling water at 100℃, pour water around the bowl wall three times, and then pour it directly into the center to fill it. The pouring time for each circle should be ≤1.5 seconds, and the total pouring time should be ≤5 seconds. After timing for 3min±2 seconds, filter out the tea soup within 5 seconds, leaving the tea leaves on the filter for tasting. The tencha sample needs to be crushed to 2-3mm particles, and the temperature during crushing should not exceed 30℃ to ensure that the effective ingredients are fully dissolved during brewing. S3. Dual-dimensional basic quantitative review: Adopting a dual-dimensional framework of appearance and internal quality, setting 6 core review indicators, and using a 5-level range of 100 points for quantitative scoring; The fixed weights for the six core evaluation indicators are: 25 points for the two indicators in the appearance dimension and 75 points for the four indicators in the internal quality dimension. The two indicators for the appearance dimension and the scoring rules are as follows: The dry tea evaluation is scored out of 10 points, mainly based on color, divided into 5 grades: Grade 1, slightly yellowish green, 1-4 points; Grade 2, tender green, 4-6 points; Grade 3, emerald green, 6-8 points; Grade 4, bright green, 8-9 points; and Grade 5, dark green, 9-10 points. See the attached document for details. Figure 2 It can be known that; The leaf base evaluation is scored out of 15 points, mainly based on color, divided into 5 levels: Level 1, slightly yellowish green, 1-6 points; Level 2, tender green, 6-9 points; Level 3, dark green, 9-12 points; Level 4, bright green, 12-14 points; Level 5, dark green, 14-15 points. See the attached document for details. Figure 2 It can be known that; The four indicators and scoring rules of the endoplasmic dimension are as follows: The soup color is evaluated on a scale of 10 points, mainly based on color and brightness, and is divided into 5 levels: Level 1 is slightly yellowish green with 1-4 points, Level 2 is light green with 4-6 points, Level 3 is emerald green with 6-8 points, Level 4 is bright green with 8-9 points, and Level 5 is dark green with 9-10 points. Aroma evaluation is scored out of 15 points, mainly based on the purity, intensity, and persistence of the aroma, divided into 5 levels. Level 1: faint aroma with off-odors (1-6 points); Level 2: relatively faint aroma with no obvious off-odors (6-9 points); Level 3: pure and relatively intense aroma (9-12 points); Level 4: pure, intense, and persistent aroma (12-14 points); Level 5: pure, intense, persistent aroma with a unique aroma (14-15 points). Off-odors include burnt, sour, stale, smoky, and musty smells. Any of these off-odors will be considered as a basis for judging Level 1 aroma. Aroma intensity and persistence are tested within 1 minute after brewing at 85℃. Off-odor testing should be conducted when the tea temperature drops to 60±5℃ to avoid high temperatures masking off-odors. The body and flavor assessment is scored out of 25 points, mainly based on the thickness and smoothness of the tea soup, and is divided into 5 levels. Level 1 tea soup is thin and rough, 1-5 points; Level 2 tea soup is relatively thin and still smooth, 5-10 points; Level 3 tea soup is of medium thickness and smooth, 10-15 points; Level 4 tea soup is relatively thick and smooth, 15-20 points; and Level 5 tea soup is thick and full-bodied, smooth and delicate, 20-25 points. The freshness assessment is scored out of 25 points, primarily based on the freshness and crispness of the tea soup, divided into 5 levels. Level 1: Poor freshness, dull taste (1-5 points); Level 2: Weak freshness, still refreshing taste (5-10 points); Level 3: Medium freshness, refreshing taste (10-15 points); Level 4: Strong freshness, refreshing and fresh taste (15-20 points); Level 5: Strong freshness, refreshing and fresh taste (20-25 points). The freshness assessment requires combining the crispness of the tea soup upon entry and the lingering freshness after swallowing; both must meet the standards to be assigned a corresponding level. Freshness refers to both the freshness and crispness of the tea soup. S4. Dynamic Score Adjustment: Based on sample quality characteristics, the basic quantitative score is adjusted using preset positive bonus items and negative deduction items to calculate the final review score of the sample; the preset rules are as follows: Positive aspects of using tea leaves: The glossiness of the leaf base is scored, specifically according to the gloss level. Level 1 is uniform color development with no localized graying / whitening, adding 0.5 points; Level 2 is rich color development with no impurities and an oily sheen, adding 1 point; Level 3 is bright and transparent color development with no impurities or dullness, adding 1.5 points. The maximum score for this part shall not exceed 20% of the total score for this indicator, that is, the glossiness score shall be ≤3 points. ② In addition to the main fragrance, any characteristic fragrance that can be jointly identified by ≥3 reviewers and lasts for ≥10 seconds is considered a stackable characteristic fragrance; 0.5 points are added for each additional characteristic fragrance, with a maximum of 3 points for this section; The characteristic aromas include seaweed aroma, chestnut aroma, vegetable aroma, mortar aroma, and floral aroma. The identification of each characteristic aroma must meet the corresponding sensory standards. Among them, seaweed aroma is a fresh aroma similar to dried seaweed; chestnut aroma is a caramel aroma similar to cooked chestnuts; vegetable aroma is a crisp aroma similar to fresh vegetables; mortar aroma is a grain aroma similar to low-temperature roasted grains; and floral aroma is a delicate fragrance similar to orchids and jasmine. Negative points deducted for grinding tea: Points will be deducted for the degree of flower and impurity in the dry tea leaves, specifically according to the degree of flower and impurity. Level 1, slight condition, with tea stems / non-tea impurities accounting for less than 5% and uneven color area less than 10%, will be deducted 0.5 points; Level 2, obvious condition, with tea stems / impurities accounting for 5%-10% and uneven color area of ​​10%-30%, will be deducted 1 point; Level 3, severe condition, with tea stems / impurities accounting for more than 10% and uneven color area of ​​more than 30%, will be deducted 1.5 points. The maximum deduction for this part shall not exceed 30% of the total score for this indicator, that is, the deduction for flower and impurity shall be ≤3 points. The deduction for brightness of the soup color is based on the degree of dullness. Slightly low brightness without turbidity is Level 1 (Slight) and deducts 0.5 points; significantly decreased brightness with slight turbidity is Level 2 (Significant) and deducts 1 point; dark soup color with significant turbidity and suspended matter is Level 3 (Severe) and deducts 1.5 points. The maximum deduction for this section is 1.5 points. Bitterness will be penalized, specifically according to the level of bitterness. Level 1, mild, is penalized 1 point for a slight bitterness that disappears completely within 10 seconds after swallowing; Level 2, obvious, is penalized 2 points for a significant bitterness that disappears within 10-30 seconds after swallowing without any residue; and Level 3, severe, is penalized 3 points for a strong bitterness that does not disappear within 30 seconds after swallowing or causes a feeling of tightness in the throat. The maximum penalty for this part is 3 points.

[0012] S5. Quality Grading Determination: The quality grades of tencha include: Grade A: 80-89 points, excellent quality, suitable for premium tea drinks and mid-to-high-end food processing; Grade B: 65-79 points, excellent quality, suitable for daily tea drinks and general food processing; Grade C: 50-64 points, good quality, suitable for industrial processing raw materials; Grade D: <50 points, basic quality, suitable for baking and processing raw materials; Following the above evaluation process, the final evaluation score of the tencha is obtained. Based on the corresponding grade, the quality grade is divided. An additional grade S can be added to the above tencha quality grades, with a score of 90-100 points. This grade is rated as excellent quality and is mainly suitable for high-end tea drinks, fine gifts, and high-end food additives.

[0013] See attached document Figure 1 It can be seen that the quality evaluation method for matcha is as follows: S1. Standardized pre-review preparations: The evaluation environment meets the requirements of GB / T18797-2012. The ambient temperature is controlled at 20-25℃, the relative humidity is controlled at 50-60%, the light is natural light from the north or standard white light, the color temperature is 5500K±500K, there is no odor, no direct light, no noise interference, and the noise here is ≤50dB. Evaluation equipment includes: a white porcelain evaluation bowl conforming to the neutral color requirements of GB / T15608-2006, with N≥9.5, a bowl height of 60mm, an outer diameter of 100mm at the top, a capacity of 200ml, and a bowl wall thickness of 3±0.5mm; an electronic balance with a sensitivity of 0.1g and an accuracy class of III; a food-grade stainless steel kettle made of 304 stainless steel; a timer with an accuracy to the second, requiring an error of ≤1 second / minute; a clean and odorless porcelain teaspoon with a capacity of 5ml±0.5ml; white A4 paper; and 100 standard matcha whisks, referring to standard bamboo whisks with 100 bristles each. Evaluators: Hold an intermediate or higher national vocational qualification certificate for tea tasters; a valid health certificate for food industry workers; uncorrected or corrected visual acuity of 5.0 or above, and no color blindness or color weakness; change into clean work clothes and clean hands with unscented hand sanitizer before evaluation; do not use cosmetics, smoke, or eat during the entire evaluation process; evaluation intervals are ≥10 minutes to avoid sensory fatigue; The water used for the assessment met the requirements of GB 5749-2022 "Standards for Drinking Water Quality". The water temperature for cold water sampling was controlled at 25℃±2℃, and the water temperature for hot water volume adjustment was controlled at 80-85℃±2℃. The water quality and temperature of the same batch of assessment water were completely consistent, with no odor or turbidity. The above standardized control requirements conform to the category-specific optimization rules based on the corresponding national standards; S2. Preparation of Standardized Matcha Samples: Take 1g of matcha sample, accurate to 0.1g, and place it in a white evaluation bowl. First, add 20mL of 25℃ purified water. Use 100 standard matcha whisks (standard bamboo whisks with 100 bristles each, 50mm±5mm in length), suspended vertically without touching the bottom of the bowl, with a spacing of 5-8mm. Stir evenly in a W-shaped or M-shaped motion at a frequency ≥120 times / minute for 15-20 seconds until no particles >0.1mm are visible to the naked eye in the tea soup. Then add 80mL of 80-85℃ purified water and stir at a stirring speed of 60 times / minute for 10 seconds until evenly mixed. Let stand for 30 seconds before evaluation. The matcha sample should be evenly spread on white A4 paper for evaluation of appearance, color, and particle fineness. S3. Dual-dimensional basic quantitative review: Adopting a dual-dimensional framework of appearance and internal quality, setting 6 core review indicators, and using a 5-level range of 100 points for quantitative scoring; The fixed weights for the six core evaluation indicators are: 25 points for the two indicators in the appearance dimension and 75 points for the four indicators in the internal quality dimension. The two indicators and scoring rules for the appearance dimension are as follows: Color evaluation is scored out of 15 points, mainly divided into 5 levels based on color: Level 1 is slightly yellowish green with 1-5 points, Level 2 is light green with 6-9 points, Level 3 is emerald green with 10-12 points, Level 4 is bright green with 13-14 points, and Level 5 is dark green with 14-15 points. The particle fineness assessment is out of 10 points, mainly divided into 5 levels based on fineness: Level 1 is not fine (1-3 points), Level 2 is slightly fine (4-5 points), Level 3 is fairly fine (6-7 points), Level 4 is fine (8-9 points), and Level 5 is soft and fine (9-10 points). The four indicators and scoring rules of the endoplasmic dimension are as follows: The soup color is evaluated on a scale of 10 points, mainly based on color and brightness, and is divided into 5 levels: Level 1 is slightly yellowish green with 1-4 points, Level 2 is light green with 4-6 points, Level 3 is emerald green with 6-8 points, Level 4 is bright green with 8-9 points, and Level 5 is dark green with 9-10 points. Aroma evaluation is scored out of 15 points, mainly based on the purity, intensity, and persistence of the aroma, divided into 5 levels. Level 1: faint aroma with off-odors (1-6 points); Level 2: relatively faint aroma with no obvious off-odors (6-9 points); Level 3: pure and relatively intense aroma (9-12 points); Level 4: pure, intense, and persistent aroma (12-14 points); Level 5: pure, intense, persistent aroma with a unique aroma (14-15 points). Off-odors include burnt, sour, stale, smoky, and musty smells. Any of these off-odors will be considered as a basis for judging Level 1 aroma. Aroma intensity and persistence are tested within 1 minute after brewing at 85℃. Off-odor testing should be conducted when the tea temperature drops to 60±5℃ to avoid high temperatures masking off-odors. The body and flavor assessment is scored out of 25 points, mainly based on the thickness and smoothness of the tea soup, and is divided into 5 levels. Level 1 tea soup is thin and rough, 1-5 points; Level 2 tea soup is relatively thin and still smooth, 5-10 points; Level 3 tea soup is of medium thickness and smooth, 10-15 points; Level 4 tea soup is relatively thick and smooth, 15-20 points; and Level 5 tea soup is thick and full-bodied, smooth and delicate, 20-25 points. The freshness assessment is scored out of 25 points, primarily based on the freshness and crispness of the tea soup, divided into 5 levels. Level 1: Poor freshness, dull taste (1-5 points); Level 2: Weak freshness, still refreshing taste (5-10 points); Level 3: Medium freshness, refreshing taste (10-15 points); Level 4: Strong freshness, refreshing and fresh taste (15-20 points); Level 5: Strong freshness, refreshing and fresh taste (20-25 points). The freshness assessment requires combining the crispness of the tea soup upon entry and the lingering freshness after swallowing; both must meet the standards to be assigned a corresponding level. Freshness refers to both the freshness and crispness of the tea soup. S4. Dynamic Score Adjustment: Based on sample quality characteristics, the basic quantitative score is adjusted using preset positive bonus items and negative deduction items to calculate the final review score of the sample; the preset rules are as follows: Positive aspects of matcha: Bonus points are awarded for color saturation, specifically based on saturation levels. Level 1 is uniform color development with no localized graying / whitening, earning 0.5 points; Level 2 is rich color development with no impurities and a glossy finish, earning 1 point; Level 3 is bright and clear color development with no impurities or dullness, earning 1.5 points. The maximum bonus for this section is 1.5 points. Aroma layering bonus: In addition to the main aroma, characteristic aromas that can be jointly identified by ≥3 reviewers and last for ≥10 seconds are considered as layerable characteristic aromas; 0.5 points are added for each additional characteristic aroma, with a maximum of 3 points for this part; the characteristic aromas include seaweed aroma, chestnut aroma, vegetable aroma, mortar aroma, and floral aroma. The identification of each characteristic aroma must meet the corresponding sensory standards, where seaweed aroma is a fresh aroma similar to dried seaweed; chestnut aroma is a caramel aroma similar to cooked chestnuts; vegetable aroma is a crisp aroma similar to fresh vegetables; mortar aroma is a grain aroma similar to low-temperature roasting; and floral aroma is a delicate fragrance similar to orchids and jasmine. Negative points deducted for matcha: Points will be deducted for the grainy texture, specifically according to the level of graininess. Level 1 is slight graininess, where very fine particles can be perceived on the tip of the tongue without any gritty feeling, and 1 point will be deducted. Level 2 is obvious graininess, where obvious particles can be perceived in the mouth with a slight gritty feeling, and 2 points will be deducted. Level 3 is severe graininess, where there is a strong grainy feeling with obvious gritty feeling and a scraping sensation in the throat, and 3 points will be deducted. The maximum deduction for this part is 3 points. The deduction for brightness of the soup color is based on the degree of dullness. Slightly low brightness without turbidity is Level 1 (Slight) and deducts 0.5 points; significantly decreased brightness with slight turbidity is Level 2 (Significant) and deducts 1 point; dark soup color with significant turbidity and suspended matter is Level 3 (Severe) and deducts 1.5 points. The maximum deduction for this section is 1.5 points. Bitterness level will be deducted points, specifically according to the degree of bitterness. Level 1, mild, is deducted 1 point for a slight bitterness that disappears completely within 10 seconds after swallowing; Level 2, obvious, is deducted 2 points for a significant bitterness that disappears within 10-30 seconds after swallowing without any residue; and Level 3, severe, is deducted 3 points for a strong bitterness that does not disappear within 30 seconds after swallowing or causes a feeling of tightness in the throat. The maximum deduction for this section is 3 points. S5. Quality Grading Determination: The specific quality grades of matcha include: Grade S: 90-100 points, excellent quality, suitable for high-end tea drinks, fine gifts, and high-end food additives; Grade A: 80-89 points, excellent quality, suitable for premium tea drinks and mid-to-high-end food processing; Grade B: 65-79 points, excellent quality, suitable for daily tea drinks and general food processing; Grade C: 50-64 points, good quality, suitable for industrial processing raw materials; Grade D: <50 points, basic quality, suitable for baking and processing raw materials; Following the above evaluation process, the final evaluation score of the matcha is obtained, and the quality grade is determined according to the corresponding level.

[0014] In the above evaluation, "freshness" refers to the vibrancy of the tea soup upon entry and the lingering freshness after swallowing, which is a comprehensive manifestation of umami substances such as amino acids; "mellowness" refers to the body and smoothness of the tea soup, which is a comprehensive manifestation of substances such as tea polyphenols and tea polysaccharides; "lingering freshness" refers to the duration of the umami flavor remaining in the mouth after swallowing the tea soup. The criteria for judging "lingering freshness" are as follows: "lingering freshness lasting ≥30 seconds" is Level 5; "lingering freshness lasting 20-30 seconds" is Level 4 (including 20 seconds); "lingering freshness lasting 10-20 seconds" is Level 3 (including 10 seconds); "lingering freshness lasting 5-10 seconds" is Level 2 (including 5 seconds); and "lingering freshness lasting <5 seconds" is Level 1.

[0015] After the evaluation of tencha and matcha is completed, a flavor characteristic assessment can be added, specifically: Reference Appendix Figure 6 It can be seen that, based on the main aroma type and core taste characteristics of the sample, a flavor feature matrix is ​​constructed with aroma type as the horizontal axis and taste characteristics as the vertical axis, and a dual identification system of grade-main aroma + secondary aroma-taste type is established. The horizontal axis represents the main aroma types, including seaweed, chestnut, grass, millstone, and floral. The vertical axis represents the core flavor characteristics, including fresh, mellow, and sweet. The criteria for fresh are a score of ≥20 for freshness, ≥20 for mellowness, and ≥15 for sweetness. The main aroma type is the characteristic aroma that has the highest proportion and longest duration in the sample. The secondary aromas are the identifiable minor characteristic aromas. There are ≤2 minor characteristic aromas. If there are more than 2 identifiable minor characteristic aromas, only the 2 with the highest intensity are recorded as secondary aromas. In the evaluation process of tencha and matcha mentioned above, when there are 3-4 evaluators, the arithmetic mean of all scores is taken as the base final score. If the relative deviation of a single evaluator's score is ≤5%, and the relative range of scores is >5%, a re-evaluation is required. When the number of evaluators who independently score is ≥5, the highest and lowest scores are removed first, and the arithmetic mean of the remaining valid scores is taken as the final score of the sample. The valid score requires that the relative deviation of a single evaluator's score is ≤5%, and the formula for calculating the relative deviation is: (single evaluator's score - average score of all evaluators) / average score × 100%. If the relative range of scores among evaluators is >5%, a re-evaluation is required. During the re-evaluation, the original evaluator and two additional evaluators jointly and independently score the same sample again, and the final score is calculated according to the same rule of removing extreme values ​​and taking the average. The re-evaluation result is the final valid score. The formula for calculating the relative range of scores is: (highest score - lowest score) / average score of all evaluators. After the quality evaluation of tencha and matcha is completed, an additional step is added to verify the evaluation results. Specifically, one set of standard samples must be set for each batch of evaluation. The standard samples are tencha / matcha samples of known grade. The evaluation score of the standard sample must deviate from the calibration value by ≤3%. Otherwise, the evaluation results of this batch are invalid and a new evaluation must be organized. All the above scoring ranges adopt the "left closed, right open" range rule. For example, in the dry tea evaluation, grade 1 green with a slight yellow tint is scored from 1 to 4 points, including 1 point but excluding 4 points. 4 points belong to the grade 2 standard, and so on.

[0016] Using the above evaluation methods, the quality ratings for tencha / matcha are as follows: Tea quality rating: Example 1, Grade S tea grinding quality: Strictly adhere to the requirements of steps S1 and S2 in the above-mentioned tencha evaluation method for standardized pre-evaluation preparation and tencha sample preparation; take 100g sample from the M1 batch of tencha products, reduce it to 3.0g using the quartering method, crush it to 2.5mm particles, place it in a 0.1mm pore size stainless steel filter, pour 100℃ boiling water around it 3 times, then pour it directly into the center to fill it, with a water pouring time of 4 seconds, and after timing 3 minutes, filter out the tea soup within 3 seconds, leaving the tea leaves for evaluation; The above samples were independently scored by five qualified evaluators, and the average baseline scores are shown in the table below:

[0017] Dynamic bonus point adjustment: Positive bonus points: Leaf gloss meets Level 3 standard, add 1.5 points; Aroma contains 3 identifiable characteristic aromas: seaweed, chestnut, and millstone aroma, add 1 point, for a total of 2.5 points; Negative deductions: Dry tea leaves without floral impurities, tea soup without bitterness or astringency, tea soup without dull color, and no off-flavors, totaling 0 points; Results processing: The final scores from the 5 evaluators were 96.2, 96.4, 96.5, 96.6, and 96.8, respectively. After removing the highest score of 96.8 and the lowest score of 96.2, the average of the remaining scores was 96.5. The relative deviation of the scores of each individual evaluator was ≤1%, which meets the rule of deviation ≤5%, and the results are valid. Conclusion: The final score of this tencha sample was 96.5, which was determined to be Grade S - Excellent quality; the flavor characteristics were identified as Grade S - Seaweed and Chestnut Dual Aroma - Fresh and Refreshing.

[0018] Example 2, Grade A tea grinding quality: Strictly adhere to the requirements of steps S1 and S2 in the above-mentioned tencha evaluation method for standardized pre-evaluation preparation and tencha sample preparation; take 100g sample from the M2 batch of tencha products, reduce it to 3.0g using the quartering method, crush it to 2.5mm particles, place it in a 0.1mm pore size stainless steel filter, pour 100℃ boiling water around it 3 times, then pour it directly into the center to fill it, with a pouring time of 4 seconds, and after 3 minutes, filter out the tea soup within 3 seconds, leaving the tea leaves for evaluation; The above samples were independently scored by five qualified evaluators, and the average baseline scores are shown in the table below:

[0019] Dynamic bonus point adjustment: Positive bonus points: 1 point for achieving a level 2 gloss level of the leaf base; 0.5 points for the aroma containing two identifiable characteristic aromas: seaweed and chestnut; total 1.5 points. Negative deductions: The dry tea stems account for 3%, which is a level 1 slight impurity, deducting 0.5 points; the tea soup has a slight bitterness, which is a level 1, deducting 1 point, for a total deduction of 1.5 points; Results processing: The final scores of the 5 evaluators were 80.8, 80.2, 80.5, 80.9 and 80.1 respectively. After removing the highest score of 80.9 and the lowest score of 80.1, the average of the remaining scores was 80.5. The relative deviation of the scores of each individual evaluator was ≤2%, which meets the rule of deviation ≤5%, so the results are valid. Conclusion: The final score of this tencha sample was 80.5, which was determined to be Grade A - Excellent quality; the flavor characteristics were identified as Grade A - Seaweed and Chestnut aroma - Mellow type.

[0020] Example 3, Grade C tea grinding quality: Strictly adhere to the requirements of steps S1 and S2 in the above-mentioned tencha evaluation method for standardized pre-evaluation preparation and tencha sample preparation; take 100g sample from the M3 batch of tencha products, reduce it to 3.0g using the quartering method, crush it to 2.5mm particles, place it in a 0.1mm pore size stainless steel filter, pour 100℃ boiling water around it 3 times, then pour it directly into the center to fill it, with a water pouring time of 4 seconds, and after timing 3 minutes, filter out the tea soup within 3 seconds, leaving the tea leaves for evaluation; The above samples were independently scored by five qualified evaluators, and the average baseline scores are shown in the table below:

[0021] Dynamic bonus point adjustment: Positive bonus points: Leaf gloss meets Level 1 standard, add 0.5 points; Aroma contains a single grassy scent without any layered notes, add a total of 0.5 points; Negative deductions: 8% of the dry tea has obvious tea stems, indicating a level 2 degree of flower and impurity, deduct 1 point; the tea soup has obvious bitterness, reaching a level 2 degree of obvious bitterness, deduct 2 points; the soup color is slightly dull, level 1, deduct 0.5 points, for a total deduction of 3.5 points. Results processing: The final scores from the 5 evaluators were 54.8, 55.2, 55.1, 54.9, and 55.0, respectively. After removing the highest score of 55.2 and the lowest score of 54.8, the average of the remaining scores was 55.0. The relative deviation of the scores from each evaluator was ≤1%, which meets the rule of deviation ≤5%, so the results are valid. Conclusion: The final score of this tencha sample was 55.0, which was determined to be Grade C - Good quality; the flavor characteristics were identified as Grade C - Grassy aroma - Sweet.

[0022] Matcha quality rating: Example 4, S-grade matcha quality: Using the S-grade tencha from Example 1 as raw material and ultra-fine grinding to make matcha powder, take 1g of sample from the matcha powder, and strictly follow the requirements of steps S1 and S2 in the above matcha evaluation method to carry out standardized pre-evaluation preparation and matcha sample preparation. The above samples were independently scored by five qualified evaluators, and the average baseline scores are shown in the table below:

[0023] Dynamic bonus point adjustment: Positive bonus points: The color is full and reaches the level 3 standard, add 1.5 points; the aroma contains three identifiable characteristic aromas: seaweed, chestnut and millstone aroma, add 1 point; total 2.5 points. Negative deductions: No grainy texture, no dull soup color, no bitterness, no off-flavors, total deduction of 0 points; Results processing: The final scores from the 5 evaluators were 99.3, 99.5, 99.7, 99.4, and 99.6, respectively. After removing the highest score of 99.7 and the lowest score of 99.3, the average of the remaining scores was 99.5. The relative deviation of the scores of each individual evaluator was ≤0.5%, which meets the rule of deviation ≤5%, and the results are valid. Conclusion: The final score of this tencha sample was 99.5, which was determined to be Grade S - Excellent quality; the flavor characteristics were identified as Grade S - Seaweed and Chestnut Dual Aroma - Fresh and Refreshing.

[0024] Example 5, Grade A Matcha Quality: Using Grade A tencha from Example 2 as raw material and ultra-fine grinding to make matcha powder, take 1g sample from the matcha powder, and strictly follow the requirements of steps S1 and S2 in the above matcha evaluation method to carry out standardized pre-evaluation preparation and matcha sample preparation. The above samples were independently scored by five qualified evaluators, and the average baseline scores are shown in the table below:

[0025] Dynamic bonus point adjustment: Positive bonus points: 1 point for full color that meets the level 2 standard; 0.5 points for aroma containing two identifiable characteristic aromas: seaweed and chestnut; total 1.5 points. Negative deductions: The tea soup has a slight bitterness (Level 1), deduct 1 point; there are no other defects, total deduction of 1 point. Results processing: The final scores from the 5 evaluators were 82.3, 82.5, 82.7, 82.4, and 82.6, respectively. After removing the highest score of 82.7 and the lowest score of 82.3, the average of the remaining scores was 82.5. The relative deviation of the scores of each individual evaluator was ≤1%, which meets the rule of deviation ≤5%, and the results are valid. Conclusion: The final score of this tencha sample was 82.5, which was determined to be Grade A - Excellent quality; the flavor characteristics were identified as Grade A - Seaweed and Chestnut aroma - Mellow type.

[0026] Example 6, Grade C matcha quality: Using the C-grade tencha from Example 3 as raw material and ultra-fine grinding to make matcha powder, take 1g of sample from the matcha powder, and strictly follow the requirements of steps S1 and S2 in the above matcha evaluation method to carry out standardized pre-evaluation preparation and matcha sample preparation. The above samples were independently scored by five qualified evaluators, and the average baseline scores are shown in the table below:

[0027] Dynamic bonus point adjustment: Positive bonus points: 0.5 points for full color that meets Level 1 standard; 0.5 points for aroma that is a single grassy scent without any layered fragrances; total 0.5 points. Negative deductions: Level 1 slight graininess deducts 1 point, Level 2 obvious bitterness deducts 2 points, Level 1 slightly dull soup color deducts 0.5 points, totaling 3.5 points deducted; Results processing: The final scores from the 5 evaluators were 61.3, 61.5, 61.7, 61.4, and 61.6, respectively. After removing the highest score of 61.7 and the lowest score of 61.3, the average of the remaining scores was 61.5. The relative deviation of the scores of each individual evaluator was ≤1%, which meets the rule of deviation ≤5%, and the results are valid. Conclusion: The final score of this tencha sample was 61.5, which was determined to be Grade C - Good quality; the flavor characteristics were identified as Grade C - Grassy aroma - Sweet.

[0028] The foregoing has shown and described the basic principles, main features, and advantages of this application. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this application. Various changes and modifications can be made to this application without departing from the spirit and scope thereof, and all such changes and modifications fall within the scope of this application as claimed. The scope of protection of this application is defined by the appended claims and their equivalents.

Claims

1. A standardized evaluation method for the quality of tencha (a type of green tea) and matcha (another type of green tea), characterized in that, Includes the following steps: S1. Standardized pre-review preparation: Complete the standardized management and control of the review environment, review equipment, review personnel, and review water, and the management and control requirements shall comply with the category-specific optimization rules based on the corresponding national standards; S2. Standardized Sample Preparation: Based on the different review targets, corresponding standardized methods are used to prepare the samples to be reviewed; When the subject of evaluation is milled tea, tea liquor and leaf samples are prepared by steeping the tea in boiling water at 100℃ for 3 minutes. When the subject of evaluation is matcha, the tea soup sample is prepared by cold water sampling followed by hot water volume adjustment. S3. Dual-dimensional basic quantitative review: Adopting a dual-dimensional framework of appearance and internal quality, setting 6 core review indicators, and using a 5-level range of 100 points for quantitative scoring; The fixed weights for the six core evaluation indicators are: 25 points for the two indicators in the appearance dimension and 75 points for the four indicators in the internal quality dimension. Among them, the two indicators in the appearance dimension are adjusted according to the evaluation object. When the evaluation object is tencha, the two indicators are dry tea evaluation and leaf residue evaluation, with weights of 10 points and 15 points respectively; when the evaluation object is matcha, the two indicators are color evaluation and particle fineness evaluation, with weights of 15 points and 10 points respectively. The four indicators of the internal quality dimension are fixed: color of soup (10 points), aroma (15 points), body (25 points), and umami (25 points). S4. Dynamic scoring adjustment: Based on the sample quality characteristics, the basic quantitative score is adjusted through preset positive bonus items and negative deduction items to calculate the final evaluation score of the sample; the preset rules include positive bonus items related to color and aroma, and negative deduction items related to impurities, off-flavors and taste defects. S5. Quality Grading Determination: Based on the final review score, the quality grade is determined, and the review process is completed.

2. The standardized evaluation method for tencha-matcha quality according to claim 1, characterized in that, The specific requirements for the standardized pre-review preparations mentioned in step S1 are as follows: (1) Review environment: meets the requirements of GB / T18797-2012, the ambient temperature is controlled at 20-25℃, the relative humidity is controlled at 50-60%, the light is natural light from the north or standard white light, there is no odor, no direct light, no noise interference, and the noise is ≤50dB; (2) Evaluation tools: including white porcelain evaluation bowls, electronic balance with a sensitivity of 0.1g and an accuracy grade of III, food-grade stainless steel kettle, timer with an accuracy to the second, clean and odorless porcelain teaspoons with a capacity of 5ml±0.5ml, and special tools for the corresponding evaluation objects, including black stainless steel tea evaluation tray for granulated tea with dimensions of 30cm×20cm×5cm; white A4 paper for matcha and 100 standard matcha whisks, referring to standard bamboo whisks with 100 bristles; (3) Evaluators: Hold a national vocational qualification certificate of intermediate or above for tea tasters, a valid health certificate for food practitioners, uncorrected or corrected visual acuity of 5.0 or above, and no color blindness or color weakness; change into clean work clothes and clean hands with unscented hand sanitizer before evaluation; do not use cosmetics, smoke or eat during the entire evaluation process; evaluation interval ≥ 10 minutes to avoid sensory fatigue; (4) Evaluation water: The physicochemical and hygienic indicators meet the requirements of GB 5749-2022 "Standards for Drinking Water Quality". The water temperature for cold water sampling of matcha is controlled at 25℃±2℃, the water temperature for hot water volume adjustment of matcha is controlled at 80-85℃±2℃, and the water temperature for brewing tencha is controlled at 100℃±2℃. The water quality and temperature of the same batch of evaluation water are completely consistent, with no odor or turbidity.

3. The standardized evaluation method for tencha-matcha quality according to claim 1, characterized in that, If and only if the object of evaluation is ground tea, the two indicators and scoring rules for the appearance dimension mentioned in step S3 are as follows: (1) Evaluation of dry tea: weight 10 points, divided into 5 scoring ranges according to color, of which Grade 1 is green with a slight yellow 1-4 points, Grade 2 is tender green 4-6 points, Grade 3 is emerald green 6-8 points, Grade 4 is fresh green 8-9 points, and Grade 5 is dark green 9-10 points. Leaf base evaluation: weighted at 15 points, divided into 5 levels based on color, with Level 1 being slightly yellowish green (1-6 points), Level 2 being tender green (6-9 points), Level 3 being dark green (9-12 points), Level 4 being bright green (12-14 points), and Level 5 being dark green (14-15 points).

4. The standardized evaluation method for tencha-matcha quality according to claim 1, characterized in that, The two indicators and scoring rules for the appearance dimension mentioned in step S3 are as follows: Only when the object of evaluation is matcha. (1) Color evaluation: weight 15 points, divided into 5 levels of scoring range according to color, of which Level 1 is slightly yellowish green 1-5 points, Level 2 is light green 6-9 points, Level 3 is emerald green 10-12 points, Level 4 is bright green 13-14 points, and Level 5 is dark green 14-15 points. Particle fineness assessment: Weighted at 10 points, it is divided into 5 levels of scoring, with Level 1 being less fine (1-3 points), Level 2 being slightly fine (4-5 points), Level 3 being fairly fine (6-7 points), Level 4 being fine (8-9 points), and Level 5 being soft and fine (9-10 points).

5. The standardized evaluation method for tencha-matcha quality according to claim 1, characterized in that, The general scoring rules for the four indicators of the endoplasmic dimension mentioned in step S3 are as follows: (1) Evaluation of soup color: weight 10 points, divided into 5 scoring ranges according to color and brightness, of which Level 1 is slightly yellowish green 1-4 points, Level 2 is light green 4-6 points, Level 3 is emerald green 6-8 points, Level 4 is bright green 8-9 points, and Level 5 is dark green 9-10 points. (2) Aroma evaluation: weighted at 15 points, divided into 5 levels based on aroma purity, intensity, and persistence. Level 1: light aroma with off-odors, 1-6 points; Level 2: light aroma with no obvious off-odors, 6-9 points; Level 3: pure and relatively strong aroma, 9-12 points; Level 4: pure, strong aroma with good persistence, 12-14 points; Level 5: pure, strong aroma with high persistence and unique aroma, 14-15 points. Off-odors include burnt, sour, stale, smoky, and musty smells. Any off-odor is considered as a basis for judging Level 1 aroma. Aroma intensity and persistence are tested within 1 minute after the tea is brewed at 85℃. Off-odors should be tested when the tea temperature drops to 60±5℃ to avoid high temperature masking off-odors. (3) Evaluation of body and flavor: weight 25 points, divided into 5 levels according to the body and smoothness of the tea soup. Level 1 tea soup is thin and rough, 1-5 points; Level 2 tea soup is relatively thin and smooth, 5-10 points; Level 3 tea soup is of medium thickness and smooth, 10-15 points; Level 4 tea soup is relatively thick and smooth, 15-20 points; Level 5 tea soup is thick and full, smooth and delicate, 20-25 points. (4) Freshness evaluation: weighted at 25 points, the tea soup is divided into 5 levels based on freshness and refreshingness. Level 1 has poor freshness and dull taste, 1-5 points; Level 2 has relatively weak freshness and still refreshing taste, 5-10 points; Level 3 has medium freshness and refreshing taste, 10-15 points; Level 4 has relatively strong freshness and refreshing taste, 15-20 points; Level 5 has strong freshness and refreshing taste, 20-25 points. The freshness evaluation should be based on the refreshing taste after the tea soup enters the mouth and the lingering freshness after swallowing. Only when both meet the standards can the corresponding level be determined.

6. The standardized evaluation method for tencha-matcha quality according to claim 1, characterized in that, The preset rules for dynamic score adjustment mentioned in step S4 are as follows: (1) Positive bonus points: ① Bonus points for tea grinding: bonus points for leaf gloss, specifically awarded according to gloss level. Level 1 is uniform color with no localized graying / whitening, adding 0.5 points; Level 2 is rich color with no impurities and an oily sheen, adding 1 point; Level 3 is bright and clear color with no impurities or dullness, adding 1.5 points. The maximum bonus for this part shall not exceed 20% of the total score for this indicator, that is, the bonus for gloss is ≤3 points. ② Bonus points for matcha-specific items: Bonus points for color saturation, specifically awarded according to saturation levels. Level 1 is uniform color development with no localized graying / whitening, adding 0.5 points; Level 2 is rich color development without impurities, and has an oily sheen, adding 1 point; Level 3 is bright and transparent color development with no impurities or dullness, adding 1.5 points. The maximum bonus points for this section are 1.5 points. ③ Bonus points for superimposed general aromas: In addition to the main aroma, characteristic aromas that can be jointly identified by ≥3 reviewers and last for ≥10 seconds are identified as superimposed characteristic aromas; 0.5 points are added for each additional characteristic aroma, with a maximum of 3 points for this part; the characteristic aromas include seaweed aroma, chestnut aroma, vegetable aroma, mortar aroma, and floral aroma, and the identification of each characteristic aroma must meet the corresponding sensory standards; (2) Negative deductions: ① Deduction Items for Tea Processing: Deductions for the degree of impurity in dry tea leaves. Specifically, deductions are based on the degree of impurity. Level 1 (Slight) deductions are given for tea stems / non-tea inclusions <5% and uneven color area <10%, with a deduction of 0.5 points. Level 2 (Significant) deductions are given for tea stems / inclusions 5%-10% and uneven color area 10%-30%, with a deduction of 1 point. Level 3 (Severe) deductions are given for tea stems / inclusions >10% and uneven color area >30%, with a deduction of 1.5 points. The maximum deduction for this section is 30% of the total score for this indicator, meaning the deduction for impurity is ≤3 points. ② Matcha-specific deduction items: Gritty texture deduction items, specifically deducted according to the gritty texture level. Among them, extremely fine particles that can be perceived on the tip of the tongue, without any gritty feeling, are Level 1 Slight Gritty Texture, deduct 1 point; obvious particles that can be perceived in the mouth, with a slight gritty feeling, are Level 2 Obvious Gritty Texture, deduct 2 points; strong gritty texture, with obvious gritty feeling and a scraping feeling in the throat, are Level 3 Severe Gritty Texture, deduct 3 points; the maximum deduction for this part is 3 points; ③ General deduction items: Deduction for brightness of soup color, points are deducted according to the degree of dullness. Slightly low brightness without turbidity is Level 1, slight condition, deduct 0.5 points; significantly decreased brightness with slight turbidity is Level 2, obvious condition, deduct 1 point; dark soup color, obvious turbidity, and the presence of suspended matter is Level 3, severe condition, deduct 1.5 points; the maximum deduction for this part is 1.5 points. Bitterness will be penalized, specifically according to the level of bitterness. Level 1, mild, is penalized 1 point for a slight bitterness that disappears completely within 10 seconds after swallowing; Level 2, obvious, is penalized 2 points for a significant bitterness that disappears within 10-30 seconds after swallowing without any residue; and Level 3, severe, is penalized 3 points for a strong bitterness that does not disappear within 30 seconds after swallowing or causes a feeling of tightness in the throat. The maximum penalty for this part is 3 points.

7. The standardized evaluation method for tencha-matcha quality according to claim 1, characterized in that, The quality grade classification rules mentioned in step S5 are as follows: Grade S: 90-100 points, excellent quality, suitable for high-end tea drinks, fine gifts, and high-end food additives; Grade A: 80-89 points, excellent quality, suitable for premium tea drinks and mid-to-high-end food processing; Grade B: 65-79 points, excellent quality, suitable for daily tea drinks and general food processing; Grade C: 50-64 points, good quality, suitable for industrial processing raw materials; Grade D: <50 points, basic quality, suitable for baking and processing raw materials.

8. The standardized evaluation method for tencha-matcha quality according to claim 1, characterized in that, Step S5 also includes flavor feature determination, specifically: based on the main aroma type and core taste features of the sample, construct a flavor feature matrix with aroma type as the horizontal axis and taste features as the vertical axis, and establish a dual identification system of grade-main aroma + secondary aroma-taste type; The horizontal axis represents the main aroma types, including seaweed, chestnut, grass, millstone, and floral. The vertical axis represents the core flavor characteristics, including fresh, mellow, and sweet. The criteria for freshness are a score of ≥20 for the freshness index, a score of ≥20 for the mellowness index, and a score of ≥15 for the sweetness index. The main aroma type is the characteristic aroma that has the highest proportion and longest duration in the sample. The secondary aromas are identifiable minor characteristic aromas, with ≤2 minor characteristic aromas.

9. The standardized evaluation method for tencha-matcha quality according to claim 1, characterized in that, When there are 3-4 reviewers, the arithmetic mean of all scores is taken as the base final score. If the relative deviation of a single reviewer's score is ≤5% and the relative range of scores is >5%, a re-evaluation is required. When there are ≥5 reviewers scoring independently, the highest and lowest scores are removed first, and the arithmetic mean of the remaining valid scores is taken as the final score of the sample. The valid scores require that the relative deviation of a single reviewer's score is ≤5%, and the formula for calculating the relative deviation is: (single reviewer's score - average score of all reviewers) / average score × 100%. If the relative range of scores among reviewers is >5%, a re-evaluation is required. During the re-evaluation, the original reviewers and two additional reviewers will jointly re-evaluate the same sample independently, and the final score will be calculated according to the same rule of removing extreme values ​​and taking the average. The re-evaluation result is the final valid score. The formula for calculating the relative range of scores is: (highest score - lowest score) / average score of all reviewers.

10. The standardized evaluation method for tencha-matcha quality according to claim 1, characterized in that, The specific operating procedures for the standardized sample preparation described in step S2 are as follows: (1) Preparation of Tencha Sample: Take 3.0g of representative Tencha sample, accurate to 0.1g, and place it in the stainless steel filter inside the tasting bowl. The stainless steel filter has a pore size of 0.1mm. Use boiling water at 100℃, pour water around the bowl wall 3 times and then pour it directly into the center to fill it. The pouring time for each circle is ≤1.5 seconds, and the total pouring time is ≤5 seconds. After timing for 3min±2 seconds, the tea soup is filtered out within 5 seconds, leaving the tea leaves on the filter for tasting. The Tencha sample needs to be crushed to 2-3mm particles. The temperature during the crushing process should not exceed 30℃ to ensure that the effective ingredients are fully dissolved during brewing. (2) Preparation of matcha sample: Take 1g of matcha sample, accurate to 0.1g, and place it in a white evaluation bowl. First, add 20mL of 25℃ purified water. Use 100 standard matcha whisks, which are standard bamboo whisks with 100 bristles each. The whisks are made of bamboo and the bristle length is 50mm±5mm. They are suspended vertically without touching the bottom of the bowl and the spacing is 5-8mm. Stir at a uniform speed in a W or M shape, with a frequency of ≥120 times / minute. Stir for 15-20 seconds until there are no visible particles >0.1mm in the tea soup. Then add 80mL of 80-85℃ purified water and stir at a stirring speed of 60 times / minute for 10 seconds until the mixture is uniform. Let it stand for 30 seconds before evaluation. The matcha sample should be evenly spread on white A4 paper for evaluation of appearance, color and particle fineness.

11. The standardized evaluation method for tencha-matcha quality according to claim 1, characterized in that, The review method also includes a review result verification step: for each batch of review, one set of standard samples calibrated by a nationally accredited institution must be set up. The relative deviation between the review score of the standard sample and the calibration value is ≤3%. Otherwise, the review result of this batch is invalid and the review needs to be reorganized.

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