CN-121978190-A - Nondestructive testing method for organic acid content of Korla bergamot pears

CN121978190ACN 121978190 ACN121978190 ACN 121978190ACN-121978190-A

Abstract

The invention relates to the technical field of Korla bergamot pear detection and discloses a Korla bergamot pear organic acid content nondestructive detection method which comprises the steps of collecting a bergamot pear sample with consistent maturity, no damage and complete surface layer, wiping the surface with absolute ethyl alcohol, naturally air-drying, only vacuum freeze-drying and crushing the surface layer, keeping the integrity of a main body, carrying out multidimensional detection on mineral elements, isotope content and ratio and volatile components by adopting ICP-MS, HT-IRMS and GC-MS/EMIS in combination with an HS-HPME extraction technology, constructing an isotope and element characteristic database and a regional characteristic volatile substance fingerprint, screening characteristic indexes through orthogonal partial least square analysis, eliminating interference factors, establishing a linear discrimination model, forming an organic acid content detection and origin identification integrated technical system, and optimizing detection parameters. The method realizes rapid and nondestructive detection and origin tracing, and provides reliable technical support for the quality evaluation of the Korla bergamot pears.

Inventors

WANG CHENQIANG
WANG JIATING
CHENG ZHIBIN
LI JING
LIU ZHONGHAI
SUN BAOXIN
ZHANG GUOYU
MA ZIQIANG
WANG XUEMING
CHAI JUAN
SHI XIAOYAN
KANG JIE

Assignees

新疆冠农股份有限公司
新疆冠农检测科技有限公司

Dates

Publication Date: 20260505
Application Date: 20251223

Claims (10)

1. The nondestructive testing method for the organic acid content of the Korla pear is characterized by comprising the following steps of: s1 sample collection Selecting Korla pears with consistent maturity and no damage, removing impurities attached to the surfaces of the Korla pears, and ensuring the integrity of the surface layer structure of the sample; S2 lossless pretreatment The surface of the sample is wiped by absolute ethyl alcohol and then naturally dried, the surface of the sample is directly subjected to freeze-drying treatment by a vacuum freeze dryer without removing cores and fruit stalks, the surface freeze-dried substance is crushed into uniform powder, and the powder is packaged and sealed for later use, so that the integrity of the sample main body is maintained in the whole process, and the damage to the commodity property of bergamot pears is avoided; s3 multi-dimensional detection S301 isotope detection Measuring the isotope content of mineral elements, O and H in a freeze-dried sample by adopting an ICP-MS technology, and synchronously establishing isotope and element characteristic databases of Korla bergamot pears in different producing areas; S302 isotope ratio detection Determining the isotope ratio of delta H and delta 18O in the freeze-dried sample by adopting HT-IRMS technology; S303 volatile component detection Determining the composition of volatile components in a freeze-dried sample by adopting a GC-MS/EMIS technology and an HS-HPME extraction method, and constructing a volatile substance fingerprint with regional characteristics; S4 detection data analysis Based on the synergistic association characteristics of the organic acid, mineral elements, stable isotopes and volatile components, screening out characteristic indexes capable of specifically representing the content of the organic acid by an orthogonal partial least squares analysis method, and eliminating unassociated interference factors; S5, establishing a linear discriminant model Inputting the screened characteristic index data into a model to obtain an organic acid content detection result, simultaneously establishing an isotope and element characteristic database and a volatile substance fingerprint to form a Korla bergamot pear organic acid content detection and origin identification integrated technical system, optimally setting ICP-MS working parameters according to mineral element and isotope detection requirements, optimally adjusting a GC-MS by adopting a capillary column adapting to volatile component separation, and optimally adjusting a temperature-raising program according to separation efficiency.
2. The nondestructive testing method for the organic acid content of the Korla bergamot pear according to claim 1, wherein in the step S2, conditions are set according to the requirement of keeping active ingredients on the surface layer of a sample by vacuum freeze drying, only the freeze-dried substances on the surface layer of the sample are collected for crushing, the crushed substances are filtered through a nylon sieve, and the crushed substances are placed into a brown sealed bottle for balancing at room temperature for standby, and the balancing process isolates external impurity pollution.
3. The method for non-destructive testing of organic acid content of Korla pear according to claim 1, wherein in step S303, ICP-MS and HS-HPME-GC-MS are combined, a surface layer freeze-dried sample is taken and placed in a headspace bottle during HS-HPME extraction, saturated NaCl solution is added, balance conditions are set according to the enrichment requirement of volatile components, an activated extraction head is inserted into the headspace bottle, and desorption is performed at a GC-MS sample inlet after adsorption for a certain time under a proper distance without contacting the sample.
4. The method for nondestructive testing of organic acid content of Korla pear according to claim 1, wherein in the step S302, in the detection of stable isotope ratio of delta H and delta 18O, nondestructive adaptation parameters of delta H and delta 18O are optimized through Gas-standard technology, a constant temperature sample tray is set at a proper temperature, CO2 and He mixed Gas with a specific proportion is filled for a sufficient time, air in a headspace bottle is thoroughly taken away, so that isotope exchange between the Gas and hydrogen and oxygen elements in a sample is fully carried out, a sample main body is prevented from being directly contacted with a testing reagent in the whole process, and nondestructive testing is strictly ensured.
5. The method for nondestructive testing of organic acid content of Korla pear according to claim 1, wherein in the step S4, correlation between organic acid and calcium, iron, copper, zinc, potassium, sodium, magnesium and manganese mineral elements and characteristic volatile components is emphasized, and the screened characteristic indexes meet the significance requirement of linear discriminant analysis.
6. The method for nondestructive testing of organic acid content of Korla pear according to claim 1, wherein in the step S5, a linear discrimination model is established by collecting Korla pear samples with different production areas and different organic acid content gradients to obtain complete detection data, performing quantitative analysis by an external standard method, constructing a feature vector containing mineral elements, isotope ratios and volatile components by combining correlation data of the content of related elements in soil of the corresponding production areas, and inputting a linear discrimination equation to obtain an organic acid content predicted value.
7. The method for nondestructive testing of organic acid content of Korla pear according to claim 1, wherein in the step S301, microwave digestion is not needed to be carried out on a sample before ICP-MS testing, the surface layer freeze-dried powder sample is directly put into a testing container, quantitative testing is carried out by an external standard method, and standard sample calibration is carried out periodically.
8. The method for nondestructive testing of organic acid content of Korla pear according to claim 1, wherein in the step S1, the samples are stored in a refrigerating mode after being collected, extrusion, collision and severe temperature change are avoided in the storing process, rewarming is not needed before the detection after the refrigerating, and nondestructive pretreatment is directly carried out.
9. The method for nondestructive testing of organic acid content of Korla pear according to claim 1, wherein in the step S5, a blind sample verification method is adopted for model verification, korla pear blind samples with different yield areas and different maturity degrees are selected, samples of a core yield area and a non-core yield area are covered, organic acid content testing and origin area association judgment are completed, and the actual values measured by an authoritative testing method are compared.
10. The method for nondestructive testing of organic acid content of Korla pear according to claim 1, wherein in the step S5, the isotope and element characteristic database and the volatile substance fingerprint comprise an organic acid content fingerprint database, the organic acid characteristic indexes of Korla pear in different producing areas are stored in association with the isotope and element characteristic database and the volatile substance regional characteristic fingerprint, and the dual functions of rapid detection of organic acid content and source tracing of origin are realized through database comparison.

Description

Nondestructive testing method for organic acid content of Korla bergamot pears Technical Field The invention relates to the technical field of detection of Korla pear, in particular to a nondestructive detection method for organic acid content of Korla pear. Background The organic acid content is one of key indexes for measuring the quality of the Korla bergamot pears, and the detection result not only provides important basis for quality evaluation, classification and sorting of the bergamot pears, but also has important significance in the fields of fruit and vegetable quality tracing, market supervision and the like, and the nondestructive detection technology has become an important development direction in the field of fruit and vegetable quality detection because damage to detection objects can be avoided. In the related technology of the existing fruit and vegetable organic acid detection, the operations such as stoning and fruit stalk stripping are usually carried out on a sample in a pretreatment stage, or the main structure of the sample is damaged by adopting a drying and crushing process, the treatment mode is derived from the design logic of the detection depending on the whole structure of the sample, so that the detected sample cannot maintain the original commodity form and the commodity attribute is destroyed, meanwhile, the existing detection method is mostly developed by adopting a single detection technology aiming at limited indexes, the internal correlation between the organic acid and mineral elements, stable isotopes and volatile components is not considered, and the technical integration of the organic acid content detection and the original place identification is not carried out, so that the detection process lacks comprehensive analysis of multidimensional characteristics, the pertinence and the accuracy of the detection result are limited, and the quality index detection and the efficient synergy of the origin tracing are difficult to realize. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a nondestructive testing method for the organic acid content of Korla pear, which aims to solve the problems that the detected sample in the background art cannot maintain the original commodity form, the commodity attribute is destroyed, the comprehensive analysis on multidimensional characteristics is lacking in the detection process, the pertinence and the accuracy of the detection result are limited, and the efficient synergy of quality index detection and origin tracing is difficult to realize. In order to achieve the purpose, the invention provides the following technical scheme that the nondestructive testing method for the organic acid content of the Korla pear comprises the following steps: s1 sample collection Selecting Korla pears with consistent maturity and no damage, removing impurities attached to the surfaces of the Korla pears, and ensuring the integrity of the surface layer structure of the sample; S2 lossless pretreatment The surface of the sample is wiped by absolute ethyl alcohol and then naturally dried, the surface of the sample is directly subjected to freeze-drying treatment by a vacuum freeze dryer without removing cores and fruit stalks, the surface freeze-dried substance is crushed into uniform powder, and the powder is packaged and sealed for later use, so that the integrity of the sample main body is maintained in the whole process, and the damage to the commodity property of bergamot pears is avoided; s3 multi-dimensional detection S301 isotope detection Measuring the isotope content of mineral elements, O and H in a freeze-dried sample by adopting an ICP-MS technology, and synchronously establishing isotope and element characteristic databases of Korla bergamot pears in different producing areas; S302 isotope ratio detection Determining the isotope ratio of delta H and delta 18O in the freeze-dried sample by adopting HT-IRMS technology; S303 volatile component detection Determining the composition of volatile components in a freeze-dried sample by adopting a GC-MS/EMIS technology and an HS-HPME extraction method, and constructing a volatile substance fingerprint with regional characteristics; S4 detection data analysis Based on the synergistic association characteristics of the organic acid, mineral elements, stable isotopes and volatile components, screening out characteristic indexes capable of specifically representing the content of the organic acid by an orthogonal partial least squares analysis method, and eliminating unassociated interference factors; S5, establishing a linear discriminant model Inputting the screened characteristic index data into a model to obtain an organic acid content detection result, simultaneously establishing an isotope and element characteristic database and a volatile substance fingerprint to form a Korla bergamot pear organic acid content detection and origin identification integrated te