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CN-121970818-A - Pueraria green tea and preparation method thereof

CN121970818ACN 121970818 ACN121970818 ACN 121970818ACN-121970818-A

Abstract

The invention discloses a preparation method of arrowroot green tea, and belongs to the technical field of tea processing. The method comprises the core steps of deactivating enzyme of tender tip of kudzu vine at 190-210 ℃ for 40-80 seconds, rolling at the temperature lower than 25 ℃, spraying a compound treatment liquid composed of kudzu vine extract and L-cysteine, and finally adopting three-stage gradient drying (60-65 ℃, 75-80 ℃ and 85-90 ℃) until the water content is less than or equal to 6%. According to the invention, a processing system for efficiently inhibiting thermal degradation of theanine is constructed through the synergistic effect of the composite treatment liquid and a specific fixation and drying process. Compared with the traditional direct baking process, the process can obviously improve the processing retention rate of theanine, can improve the content of finished theanine by several times, and simultaneously keeps higher total flavone content, so that the arrowroot green tea product with fresh and cool flavor and high nutritive value is prepared, and the high-value utilization of arrowroot resources is realized.

Inventors

  • WANG AIQIN
  • LIAO LANGPING
  • HE LONGFEI
  • Pan Qiyou
  • XIAO DONG
  • HUANG JINGLI
  • ZHAN JIE
  • ZHANG PINGGANG

Assignees

  • 广西大学

Dates

Publication Date
20260505
Application Date
20260209

Claims (8)

  1. 1. A preparation method of high theanine content arrowroot green tea is characterized by comprising the following steps: (1) Raw material treatment, namely picking tender tips of arrowroot, cleaning, draining and cutting into sections; (2) Deactivating enzyme, namely deactivating enzyme of the arrowroot segments at 190-210 ℃ for 40-80 seconds; (3) Twisting and treating, namely uniformly spraying compound treating fluid on the surface of the arrowroot segments during or after twisting, wherein the twisting is carried out under the condition that the ambient temperature is lower than 25 ℃; (4) And (3) drying, namely drying the arrowroot segments sprayed with the treatment liquid to reduce the water content to below 6%.
  2. 2. The method according to claim 1, wherein the drying in the step (4) is performed by sectional drying, specifically, drying at 60-65 ℃ for 20-40 minutes, drying at 75-80 ℃ for 15-30 minutes, and drying at 85-90 ℃ for 10-20 minutes until the water content is less than or equal to 6%.
  3. 3. The method of claim 1, wherein the complex treatment fluid consists of pueraria extract and L-cysteine.
  4. 4. The method according to claim 3, wherein the preparation method of the compound treatment liquid comprises extracting radix Puerariae powder with 60-70% ethanol water solution, concentrating the extractive solution to obtain radix Puerariae concentrated extract, adding 0.8-1.2% L-cysteine, mixing, and adjusting pH to 5.5-6.5.
  5. 5. The method of claim 4, wherein the compound treatment fluid is sprayed in an amount of 5-10% by weight of the kudzu segments.
  6. 6. The method according to claim 1, wherein in the step (2), the deactivation temperature is 200 ℃ and the deactivation time is 60 seconds.
  7. 7. The method according to claim 1, wherein the variety of the tender tip of kudzu in the step (1) is "Guige No. 8".
  8. 8. A green arrowroot tea prepared by the method of any one of claims 1-7.

Description

Pueraria green tea and preparation method thereof Technical Field The invention belongs to the technical field of tea processing, and particularly relates to arrowroot green tea and a preparation method thereof. Background The development and application of the underground root tuber of the kudzu vine serving as an important plant with homology of medicine and food are mature, but the deep development and high-valued utilization of the overground vine stem part (namely kudzu vine) with huge yield still have obvious defects. At present, the potential of the arrowroot serving as a drink raw material is not fully exploited except a small amount of arrowroot serving as a feed. In the prior art, some attempts to replace tea by kudzu have been made, but the schemes mainly have two types of limitations, namely, the process center of gravity is in the compounding of raw materials and not in the fine processing of the kudzu. For example, chinese patent CN107125397a discloses a tea substitute compounded with multiple plants including arrowroot, which is technically characterized in that the compatibility and mixing of raw materials do not design a dedicated tea making process aiming at the physicochemical property of the arrowroot as a single raw material. Secondly, the existing scheme fails to systematically design for retention of theanine, a core quality component in the tea making process. For example, chinese patent CN105475566a relates to compounding a kudzuvine root extract with mountain green tea, which essentially uses kudzuvine root as a functional additive, instead of developing tea leaves with kudzuvine root as a main body, and does not reach the problem of conversion and retention of the intrinsic components of kudzuvine root in the tea making process. Theanine is a key water-soluble amino acid for determining the quality and health value of green tea, and the content of theanine directly influences the fresh and mellow taste of tea soup, and is also one of important health active ingredients. However, theanine has remarkable heat sensitivity, and is extremely easy to degrade or volatilize in the heat treatment procedures of fixation, drying and the like, so that the flavor and the nutritional value of the finished tea are reduced. In the traditional fresh tea processing, this loss has been difficult to avoid completely. The arrowroot is used as a brand new tea making raw material, the tissue structure, the enzyme system composition and the inclusion basis of the arrowroot are basically different from those of fresh tea leaves, and the conventional green tea processing experience cannot be directly applied. In the prior art, no simple compound scheme or reference to the traditional processing method is provided, a set of effective schemes capable of systematically solving the specific technical problem that theanine is lost in a large amount in the process of converting the arrowroot raw material into green tea are provided. Therefore, how to improve the theanine retention rate in the arrowroot green tea is a technical problem to be solved in the art. Disclosure of Invention In view of the above, it is necessary to provide a preparation method of a arrowroot green tea, which can effectively inhibit the loss in the processing process by specific process combination aiming at the characteristics of low theanine background value and unstable heat of arrowroot raw material, thereby remarkably improving the retention rate of theanine in the finished product and improving the flavor. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: a preparation method of high theanine content arrowroot green tea comprises the following steps: (1) Raw material treatment, namely picking tender tips of arrowroot, cleaning, draining and cutting into sections; (2) Deactivating enzyme, namely deactivating enzyme of the arrowroot segments at 190-210 ℃ for 40-80 seconds to deactivate polyphenol oxidase activity; (3) Twisting and treating, namely uniformly spraying compound treating fluid on the surface of the arrowroot segments during or after twisting, wherein the twisting is carried out under the condition that the ambient temperature is lower than 25 ℃; (4) And (3) drying, namely drying the arrowroot segments sprayed with the treatment liquid to reduce the water content to below 6%. In the invention, further, the drying in the step (4) is sectional drying, specifically, drying for 20-40 minutes at 60-65 ℃, drying for 15-30 minutes at 75-80 ℃, and finally drying for 10-20 minutes at 85-90 ℃ until the water content is less than or equal to 6%. In the invention, further, the compound treatment liquid consists of a kudzuvine root extract and L-cysteine. The preparation method of the composite treatment liquid further comprises the steps of extracting the kudzuvine root powder with an ethanol water solution with the concentration of 60-70%, concentrating the extract to obtain a kudzuvi