CN-122016688-A - White tea quality judging method and related equipment

CN122016688ACN 122016688 ACN122016688 ACN 122016688ACN-122016688-A

Abstract

The invention relates to a method for distinguishing the quality of white tea and related equipment. The method comprises the steps of obtaining ultraviolet-visible diffuse reflection spectrum data of a white tea sample to be detected, wherein the wavelength range of the spectrum data covers an ultraviolet region to a near infrared short wave region, performing first preprocessing on the spectrum data, performing origin authenticity judgment on the white tea sample to be detected by adopting a chemometric method based on the spectrum data after the first preprocessing and a first characteristic wavelength set, obtaining origin authenticity judgment results, performing second preprocessing on the spectrum data when the origin authenticity judgment results are pure materials of a target origin region, and performing grade judgment on the white tea sample to be detected by adopting the chemometric method based on the spectrum data after the second preprocessing and the second characteristic wavelength set, thereby obtaining grade judgment results. The method reduces the distinguishing cost of the quality of the white tea and improves the distinguishing accuracy.

Inventors

CHEN QINFANG
LIU XING
SONG WEIGUO
Shao Ruoting

Assignees

上海市农业科学院

Dates

Publication Date: 20260512
Application Date: 20260415

Claims (10)

1. The method for distinguishing the quality of the white tea is characterized by comprising the following steps of: Acquiring ultraviolet-visible diffuse reflection spectrum data of a white tea sample to be detected, wherein the wavelength range of the spectrum data covers an ultraviolet region to a near infrared short wave region; Performing first preprocessing on the spectrum data, and performing production place authenticity judgment on the white tea sample to be detected based on the spectrum data subjected to the first preprocessing and a first characteristic wavelength set by adopting a chemometric method to obtain a production place authenticity judgment result; And when the authenticity distinguishing result of the producing area is the pure material of the target producing area, performing second pretreatment on the spectrum data, and performing grade distinguishing on the white tea sample to be measured by adopting a chemometric method based on the spectrum data subjected to the second pretreatment and a second characteristic wavelength set to obtain a grade distinguishing result.
2. The method of claim 1, wherein when the origin authenticity determination is a non-target origin puree or blendstock, the method further comprises: Terminating the execution of the level discrimination, or, And executing grade discrimination, and adding a risk marker to the obtained grade discrimination result.
3. The method according to claim 1, wherein the method further comprises: Acquiring ultraviolet-visible diffuse reflection spectrum data of white tea samples with known production places and known grades as a training data set; calculating a first contribution degree value of each wavelength variable in the full-band spectrum of the training data set to the authenticity discrimination of the production place based on variable projection importance analysis, and screening out the wavelength variable with the first contribution degree value higher than a first preset threshold value as the first characteristic wavelength set, wherein the first characteristic wavelength set at least comprises wavelength variables in an ultraviolet region and a visible light region; Calculating a second contribution degree value of each wavelength variable in the full-band spectrum of the training data set to the level discrimination based on variable projection importance analysis, and screening out a wavelength variable with the second contribution degree value higher than a second preset threshold value as a second characteristic wavelength set, wherein the second characteristic wavelength set at least comprises wavelength variables in a near infrared short wave region; the first contribution degree value and the second contribution degree value are variable projection importance values.
4. A method according to claim 3, wherein the trained dataset further comprises white tea samples having different blending ratios, the white tea samples having different blending ratios being obtained by mixing white tea samples of at least two known origin at a predetermined ratio; the origin authenticity judgment is configured to identify the pure materials in the target origin area, the pure materials in the non-target origin area and the blending samples with different proportions in the white tea sample to be detected.
5. The method of claim 1, wherein the step of determining the position of the substrate comprises, The first preprocessing comprises scattering correction and derivative processing in sequence; The second preprocessing includes smoothing, scatter correction, and derivative processing in order.
6. The method of claim 1, wherein the chemometric method comprises at least one of a partial least squares discriminant analysis method, a principal component analysis method, and a linear discriminant analysis method.
7. The method according to claim 1, wherein the wavelength range of the ultraviolet-visible diffuse reflection spectrum data is 190-1100 nm, the white tea sample to be tested is dry tea powder which is crushed and screened, and the screening process corresponds to a screening mesh number of 60-100 meshes.
8. A white tea quality discriminating apparatus, comprising: the system comprises a spectrum data acquisition module, a white tea sample detection module and a white tea sample detection module, wherein the spectrum data acquisition module is used for acquiring ultraviolet-visible diffuse reflection spectrum data of a white tea sample to be detected, and the wavelength range of the spectrum data covers an ultraviolet region to a near infrared short wave region; the origin discrimination module is used for carrying out first pretreatment on the spectrum data, adopting a chemometric method, and carrying out origin authenticity discrimination on the white tea sample to be detected based on the spectrum data subjected to the first pretreatment and a first characteristic wavelength set to obtain origin authenticity discrimination results; And the grade judging module is used for carrying out second pretreatment on the spectrum data when the authenticity judging result of the producing area is the pure material of the target producing area, and carrying out grade judgment on the white tea sample to be detected by adopting a chemometric method based on the spectrum data subjected to the second pretreatment and a second characteristic wavelength set to obtain a grade judging result.
9. The apparatus of claim 8, wherein the spectral data acquisition module comprises a full band spectrophotometer or a combination of a discrete narrowband light source and a photosensor, wherein the discrete narrowband light source comprises at least an ultraviolet light source emitting in the ultraviolet region, a visible light source emitting in the visible region, and a near infrared light source emitting in the near infrared short wavelength region.
10. A non-transitory machine readable medium storing computer instructions for causing a computer to perform the method of any one of claims 1 to 7.

Description

White tea quality judging method and related equipment Technical Field The invention relates to the technical field of tea quality judgment, in particular to a method and related equipment for judging the quality of white tea. Background White tea belongs to slightly fermented tea, has rich active enzymes and polyphenols, and is favored by consumers. The special production environment and the traditional process of the geographical mark products such as Fuding white tea have higher market value. The quality characteristics of the white tea are mainly characterized in that firstly, the production area attribute and the natural condition difference of climate, soil and the like of the white tea in different production areas are obviously different in internal quality and market price, and secondly, the grade attribute is that the white tea can be divided into a plurality of grades of peonies, shou eyebrows and the like according to the picking standard and the raw material tenderness, and the price difference among the different grades is very different. However, driven by high profit, the white tea market is currently faced with a severe 'trust crisis', and the problems of false production place, difficult tracing across production places, fuzzy adjacent-level sensory characteristics and the like, which cause misjudgment of the quality of the white tea, exist. In view of the above problems in the related art, no effective solution has been proposed at present. Disclosure of Invention The method and the related equipment for distinguishing the quality of the white tea at least partially solve the problems of high distinguishing cost and low distinguishing accuracy of the quality of the white tea in the related technology. In order to solve the above problems, an aspect of an embodiment of the present invention provides a method for determining quality of white tea, including: Acquiring ultraviolet-visible diffuse reflection spectrum data of a white tea sample to be detected, wherein the wavelength range of the spectrum data covers an ultraviolet region to a near infrared short wave region; Performing first preprocessing on the spectrum data, and performing production place authenticity judgment on the white tea sample to be detected based on the spectrum data subjected to the first preprocessing and a first characteristic wavelength set by adopting a chemometric method to obtain a production place authenticity judgment result; And when the authenticity distinguishing result of the producing area is the pure material of the target producing area, performing second pretreatment on the spectrum data, and performing grade distinguishing on the white tea sample to be measured by adopting a chemometric method based on the spectrum data subjected to the second pretreatment and a second characteristic wavelength set to obtain a grade distinguishing result. In some embodiments, when the origin authenticity determination is a non-target origin pure or blended sample, the method further comprises: Terminating the execution of the level discrimination, or, And executing grade discrimination, and adding a risk marker to the obtained grade discrimination result. In some of these embodiments, the method further comprises: Acquiring ultraviolet-visible diffuse reflection spectrum data of white tea samples with known production places and known grades as a training data set; calculating a first contribution degree value of each wavelength variable in the full-band spectrum of the training data set to the authenticity discrimination of the production place based on variable projection importance analysis, and screening out the wavelength variable with the first contribution degree value higher than a first preset threshold value as the first characteristic wavelength set, wherein the first characteristic wavelength set at least comprises wavelength variables in an ultraviolet region and a visible light region; Calculating a second contribution degree value of each wavelength variable in the full-band spectrum of the training data set to the level discrimination based on variable projection importance analysis, and screening out a wavelength variable with the second contribution degree value higher than a second preset threshold value as a second characteristic wavelength set, wherein the second characteristic wavelength set at least comprises wavelength variables in a near infrared short wave region; the first contribution degree value and the second contribution degree value are variable projection importance values. In some embodiments, the trained data set further comprises white tea samples with different blending ratios, the white tea samples with different blending ratios being obtained by mixing white tea samples of at least two known producing areas in a preset ratio; the origin authenticity judgment is configured to identify the pure materials in the target origin area, the pure materials in the non-target origin area