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CN-122004313-A - Bean-flavor Longjing raw material tea processing method based on novel technology of powder-light coupling magnetic induction and spreading

CN122004313ACN 122004313 ACN122004313 ACN 122004313ACN-122004313-A

Abstract

The invention provides a bean-flavored Longjing tea processing method based on a novel bean-flavored Longjing tea leaf spreading technology through coupling of pink light, which comprises the core steps of uniformly spreading fresh leaves of the dried Longjing tea leaves on a spreading frame, intermittently irradiating leaf layers by using a pink light wave band light source (600-680 nm) with specific wavelength and light intensity, simultaneously applying an alternating weak magnetic field (with the frequency of 5-50Hz and the intensity of 1-10 mT) below the leaf layers, and dynamically adjusting photo-magnetic coupling parameters until the spreading is moderate by monitoring the temperature, the humidity and the color change of leaf surfaces of the leaf layers in real time through a sensor. The method promotes the moisture migration, enzyme activity excitation and directional conversion of flavor precursor substances in the tea leaves by the cooperation of the photo-magnetic coupling effect, realizes the accurate, uniform and efficient control of the spreading process, and remarkably improves the bean fragrance quality of the Longjing raw material tea.

Inventors

  • ZHANG JIANYONG
  • YIN JUNFENG
  • CHEN JIANXIN
  • WANG WEIWEI
  • WANG FANG
  • XU YONGQUAN
  • CHEN GENSHENG

Assignees

  • 中国农业科学院茶叶研究所

Dates

Publication Date
20260512
Application Date
20251218

Claims (7)

  1. 1. The processing method of the bean-flavored longjing raw material tea based on the novel technology of powder-light coupling magnetic induction and spreading green is characterized by comprising the following steps: 1) Spreading leaves, namely uniformly spreading fresh tea leaves on a powder-light coupling magnetic induction spreading device, wherein the spreading thickness is 2-5 cm; 2) The method comprises the steps of (1) starting a powder light irradiation device arranged above a powder light coupling magnetic induction spreading device, and periodically and intermittently irradiating a leaf layer by using light beams with the wavelength range of 600-680 nm and the illumination intensity of 100-500 lux, wherein the irradiation time of each period is 10-30 min, and the interval time is 5-15 min; 3) The magnetic induction treatment, namely synchronously starting a magnetic field generating device integrated in the powder light coupling magnetic induction water-spreading device, and applying an alternating weak magnetic field with the frequency of 5-50 Hz and the magnetic induction intensity of 1-10 mT to a leaf layer; 4) The intelligent regulation and control and end point judgment comprises the steps of monitoring state parameters of leaf layers in real time through a temperature and humidity sensor and an image acquisition device which are arranged in a spreading area, dynamically adjusting illumination parameters of powder light irradiation and magnetic field parameters of magnetic induction treatment according to the monitored state parameters until the water loss rate of fresh leaves reaches 15% -25%, the leaf color is changed into dark green and aroma is exposed, and finishing spreading to obtain spreading leaves; 5) And (3) carrying out subsequent processing, namely sequentially carrying out strip tidying and enzyme deactivation, air separation, continuous flattening and aroma extraction on the green leaf to obtain the bean-flavored longjing raw material tea.
  2. 2. The processing method of the bean-flavored longjing raw material tea based on the novel technology of powder light coupling magnetic induction and spreading and fixation as claimed in claim 1, wherein the powder light irradiation device adopts an LED light source, and the dominant wavelength of the powder light irradiation device is 630 nm +/-10 nm.
  3. 3. The bean-flavored longjing raw material tea processing method based on the novel technology of powder light coupling magnetic induction and spreading green is characterized in that the illumination parameters of the dynamic adjustment of powder light irradiation are specifically that the illumination mode is dynamically adjusted according to the center temperature of a leaf layer monitored by a temperature and humidity sensor: When the center temperature of the leaf layer is lower than 22 ℃, adopting a continuous irradiation mode; when the center temperature of the leaf layer is between 22 and 28 ℃, the periodic intermittent irradiation mode is adopted; when the center temperature of the leaf layer is higher than 28 ℃, irradiation is suspended and ventilation is enhanced.
  4. 4. The bean-flavored longjing raw material tea processing method based on the novel technology of powder-light coupling magnetic induction and spreading and fixation, which is disclosed in claim 1, is characterized in that the magnetic field direction of the alternating weak magnetic field is perpendicular to the leaf plane, the magnetic field frequency is related to the on-off rhythm of illumination, the magnetic field frequency is set to be 20-50 Hz in the illumination on period, and the magnetic field frequency is adjusted to be 5-20 Hz in the illumination off period.
  5. 5. The bean aroma Longjing tea processing method based on the novel technology of powder light coupling magnetic induction and spreading and fixation is characterized in that illumination parameters and magnetic field parameters are dynamically adjusted according to state parameters, specifically, the bean aroma Longjing tea processing method comprises the steps of obtaining leaf surface images through an image acquisition device, analyzing RGB values of leaf surface colors, judging that the spreading and fixation process is close to moderate when the green channel value of the leaf surface colors is reduced to 70% -80% of the initial value and the red channel value is increased, and gradually reducing the magnetic field intensity of the light intensity magnetic induction treatment of powder light irradiation.
  6. 6. The bean-flavored longjing raw material tea processing method based on the novel technology of powder-light coupling magnetic induction and tedding is characterized in that the powder-light coupling magnetic induction and tedding device is of a multi-layer structure, and each layer is independently provided with the powder light irradiation device, the magnetic field generating device and the temperature and humidity sensing monitoring device to realize independent and accurate layered control.
  7. 7. The bean-flavored Longjing tea processing method based on the novel technology of powder-light coupling magnetic induction and spreading and fixation, which is disclosed in claim 1, is characterized in that the temperature of strip tidying and fixation is 280-320 ℃ and the time is 5min, the temperature of flattening is 170-190 ℃ and the time is 4-min, and the temperature of aroma raising is 80-100 ℃ and the time is 30-40 min.

Description

Bean-flavor Longjing raw material tea processing method based on novel technology of powder-light coupling magnetic induction and spreading Technical Field The invention belongs to the technical field of tea processing, and particularly relates to a method for spreading tea leaves of a Longjing raw material based on physical field regulation, in particular to a method for accurately regulating and controlling the spreading tea leaves of the Longjing raw material by utilizing the coupling effect of pink light and a magnetic field. Background Spreading is a key process after the front opening in the production of Longjing tea. The traditional spreading mainly depends on spreading under natural conditions, and a series of slow biochemical reactions in fresh leaves are initiated by slow evaporation of water, so that a foundation is laid for subsequent fixation. However, the traditional method is greatly influenced by weather, temperature and humidity environments, has poor spreading uniformity, takes different time (usually needs 6-10 h), has unstable quality and is seriously dependent on the experience of tea-making master. In the prior art, some devices and methods for attempting to improve the spreading process are presented, for example, patent cn201710329430. X discloses a spreading house with controllable temperature and humidity, and a stable environment is created through an air conditioning system. However, the method only controls the macroscopic environment, has weak active regulation and control effect on the conversion of substances in the tea, and has higher energy consumption. In addition, there are studies on attempts to treat tea leaves using a single physical field such as far infrared rays, specific blue light and the like, but the effects of promoting uniformity and improving fragrance quality are limited, and the problems of poor fragrance improving effect and insufficient synergistic effect exist. Therefore, how to provide a new method capable of actively, accurately and uniformly regulating and controlling the tea spreading process of the Longjing tea raw material, reducing environmental dependence and improving the quality and stability of aroma is a technical problem to be solved in the field. Disclosure of Invention Aiming at the problems existing in the prior art, the invention aims to provide a processing method of bean-flavored Longjing tea raw material based on a novel technique of powder-light coupling magnetic induction and spreading, according to the method, the physiological and biochemical processes of the tea are cooperatively regulated and controlled through the coupling effect of the pink light and the alternating weak magnetic field, and the quick, uniform and accurate spreading of the tea is realized, so that the color, aroma and taste quality of the Longjing raw material tea is stabilized and improved. In order to achieve the above purpose, the technical scheme provided by the invention is as follows: A processing method of bean-flavored Longjing tea raw materials based on a novel technology of powder-light coupling magnetic induction and spreading green tea is characterized by constructing a physical field regulation and control environment of light and magnetic coupling. The method comprises the following specific steps: Spreading leaves, namely uniformly and loosely spreading fresh leaves (usually primary spreading of one bud and two leaves or one bud and three leaves) of the dragon well raw material tea after moderate withering on a special powder photo-coupling magnetic induction spreading device. The device of should spreading out green has printing opacity and does not influence the bed surface characteristics of magnetic field, specifically, this device of spreading out green adopts the iron baffle to carry out the layering, and every layer all independently disposes powder light irradiation device, magnetic field generating device and humiture sensing monitoring device, realizes layering independent accurate control. The powder light irradiation device is a powder light LED lamp tube, the magnetic field generating device comprises a magnetic heating looper layer, and the temperature and humidity sensing monitoring device comprises a temperature and humidity sensor. And (3) performing pink illumination, namely starting a pink LED light source array positioned above the leaf layer. The pink light with the wave band of 600-680 nm is selected, the photon energy of the wave band is moderate, the photon energy can be absorbed by mesophyll cells, the leaf temperature is gently raised, the activities of protease, ester oxygenase, amylase and the like are promoted, and meanwhile, the light inhibition or the generation of excessive heat can not be caused, so that the 'worry' is not caused. The intermittent irradiation mode is adopted to simulate the natural light circadian rhythm, so that the physiological recovery period of the tea is endowed, and the accumulation of fla