Red Fuji apple production place discrimination method based on organic component analysis

Abstract

The invention relates to the technical field of apple production place detection, in particular to a red Fuji apple production place discrimination method based on organic component analysis, which comprises the following steps: S1, constructing a linear discrimination function of organic components such as oxalic acid, succinic acid, tartaric acid, citric acid, malic acid, phlorizin, chlorogenic acid and rutin; s2, obtaining the contents of oxalic acid, succinic acid, tartaric acid, citric acid, malic acid, phlorizin, chlorogenic acid and rutin in the apple sample to be detected; s3, inputting the contents of oxalic acid, succinic acid, tartaric acid, citric acid, malic acid, phlorizin, chlorogenic acid and rutin in the obtained apple sample to be detected into the linear discrimination function, and taking a group of maximum discrimination function calculation values as a production area detection result. According to the method, the production places of red Fuji apples in five production areas can be discriminated to a certain extent through linear discrimination established on the basis of eight organic components, the classification accuracy rate reaches 95.2%, and technical support is provided for the production place traceability of the Jinning apples and the quality control of the apples.

Description

Technical Field

[0001] This invention relates to the field of apple origin detection technology, specifically to a method for determining the origin of Fuji apples based on organic component analysis. Background Technology

[0002] As a major apple variety in my country, the Fuji apple holds significant research value within the apple industry. However, in recent years, some unscrupulous merchants, driven by greed, have been artificially packaging and counterfeiting Fuji apples, falsely claiming them to be protected by the national geographical indication. This phenomenon is rampant. Such counterfeiting and selling inferior products not only directly causes economic losses to consumers and severely disrupts the normal market order, but also increases the difficulty of tracing and managing food safety issues. To strengthen apple quality and safety testing and monitoring, effectively protect consumer rights, build the brand and image of Jingning apples, promote the healthy development of apple trade, and fill the gap in apple origin identification in Gansu, it is urgently necessary to establish a rapid and accurate apple origin traceability technology system.

[0003] Organic component analysis can serve as a chemical technique for tracing the origin of agricultural products. Although the organic components in apples, such as organic acids, polyphenols, and vitamin C (ascorbic acid), change during tree growth and fruit storage, the composition and content of organic components in apples from different regions exhibit certain differences after harvest. Analyzing these differences can, to some extent, achieve the goal of apple origin tracing. In recent years, research on apple organic components has been quite common, with in-depth studies on organic acids, apple phenols, and ascorbic acid. However, research on the differential characteristics of organic components in apples from different producing areas is relatively limited. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a method for determining the origin of Fuji apples based on organic component analysis, which can help identify the origin of Fuji apples.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for determining the origin of Fuji apples based on organic component analysis includes the following steps:

[0007] S1. Construct linear discriminant functions for the organic components oxalic acid, succinic acid, tartaric acid, citric acid, malic acid, phlorizin, chlorogenic acid, and rutin:

[0008] Y 甘肃静宁 =-92.464+4.235X 根皮苷 +4.394X 绿原酸 +0.489X 芦丁 +0.346X 草酸 +0.510X琥珀酸

[0009] +0.007X 酒石酸 -0.052X 柠檬酸 +0.008 苹果酸 ;

[0010] Y 山东栖霞 =-149.586+10.464X 根皮苷 +5.893X 绿原酸 +4.800X 芦丁 +0.282X 草酸 -0.509X 琥珀

[0011] 酸 -0.106X 酒石酸 +0.396X 柠檬酸 +0.012X 苹果酸 ;

[0012] Y 陕西洛川 =-117.187+12.067X 根皮苷 +5.481X 绿原酸 +0.880X 芦丁 +0.280X 草酸 -0.345X 琥珀

[0013] 酸 +0.007X 酒石酸 +0.467X 柠檬酸 +0.010X 苹果酸 ;

[0014] Y 甘肃西峰 =-115.644+15.814X 根皮苷 +5.889X 绿原酸 +0.852X 芦丁 +0.279X 草酸 -0.182X 琥珀

[0015] 酸 -0.138X 酒石酸 +0.463X 柠檬酸 +0.011X 苹果酸 ;

[0016] Y 甘肃秦安 =-142.427+17.642X 根皮苷 +8.653X 绿原酸 +0.033X 芦丁 +0.321X 草酸 +0.272X 琥珀

[0017] 酸 -0.114X 酒石酸 +0.063X 柠檬酸 +0.013X 苹果酸 ;

[0018] In the formula, Y 甘肃静宁 Y 山东栖霞 Y 陕西洛川 Y 甘肃西峰 Y 甘肃秦安 —Discriminant function values ​​for Fuji apples from Jingning (Gansu), Qixia (Shandong), Luochuan (Shaanxi), Xifeng (Gansu), and Qin'an (Gansu); X 根皮苷 X 绿原酸 X 芦丁 X 草酸 X 琥珀酸 X 酒石酸 X 柠檬酸 X 苹果酸 —Contents of phlorizin, chlorogenic acid, rutin, oxalic acid, succinic acid, tartaric acid, citric acid and malic acid in apples, mg / kg;

[0019] S2. Obtain the contents of oxalic acid, succinic acid, tartaric acid, citric acid, malic acid, phlorizin, chlorogenic acid and rutin in the apple sample to be tested;

[0020] S3. The contents of oxalic acid, succinic acid, tartaric acid, citric acid, malic acid, phlorizin, chlorogenic acid and rutin in the obtained apple samples to be tested are entered into the linear discriminant function, and the group with the largest discriminant function value is taken as its place of origin detection result.

[0021] Further, step S1 includes the following steps:

[0022] S11. Based on the national standard, 21 organic components of Red Fuji apples from five production areas—Jingning in Gansu, Qixia in Shandong, Luochuan in Shaanxi, Xifeng in Gansu, and Qin'an in Gansu—were determined using high-performance liquid chromatography (HPLC). HPLC fingerprints of apple organic acids, polyphenols, and ascorbic acid were obtained, and eight organic components with significant differences were screened out: oxalic acid, succinic acid, tartaric acid, citric acid, malic acid, phlorizin, chlorogenic acid, and rutin.

[0023] S12. Project the features of oxalic acid, succinic acid, tartaric acid, citric acid, malic acid, phlorizin, chlorogenic acid, and rutin, which are labeled with classification groups, onto a straight line. Determine the coefficients of the linear discriminant function by finding that the sample projection values ​​on this line reach the maximum or minimum distance between sample categories. Establish the linear discriminant function.

[0024] In the above scheme, the linear discrimination based on eight organic components can, to a certain extent, identify the origin of Fuji apples from five production areas, with a classification accuracy of 95.2%, providing technical support for the traceability of Jingning apple production areas and the quality control of apples. Attached Figure Description

[0025] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0026] Figure 1 HPLC fingerprints of organic acids from 104 batches of apple samples.

[0027] Figure 2 HPLC fingerprints of polyphenols from 104 batches of apple samples.

[0028] Figure 3 HPLC fingerprints of ascorbic acid from 104 batches of apple samples.

[0029] Figure 4 This is a bipolar analysis diagram of the principal components of organic compounds in apples.

[0030] Figure 5 This is a graph showing Apple's PLS-DA score.

[0031] Figure 6 This is a graph showing the score of the discriminant function. Detailed Implementation

[0032] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0033] Experimental data:

[0034] 1. Materials and Methods

[0035] 1.1 Materials and Reagents

[0036] This experiment used Red Fuji apples from five regions: Jingning in Gansu, Qixia in Shandong, Luochuan in Shaanxi, Xifeng in Gansu, and Qin'an in Gansu as samples. The Red Fuji apples from Jingning, Qixia, Luochuan, Xifeng, and Qin'an were sourced from local orchards. There were 64 samples from Jingning, Gansu, and 10 samples each from Qixia, Luochuan, Xifeng, and Qin'an.

[0037] Organic acid standard substances were obtained from Alta Technology Co., Ltd.; polyphenol standard substances were obtained from Tanmo Quality Inspection Technology Co., Ltd.; ascorbic acid standard substances were obtained from Tanmo Quality Inspection Technology Co., Ltd.

[0038] 1.2 Instruments and Equipment

[0039] Mettler electronic balance (Mettler-Toledo Instruments (Shanghai) Co., Ltd.); T25 high-speed homogenizer (Aika (Guangzhou) Instrument Equipment Co., Ltd.); KS4000 Aika temperature-controlled shaking insulator (Aika (Guangzhou) Instrument Equipment Co., Ltd.); RV10 rotary evaporator (Aika (Guangzhou) Instrument Equipment Co., Ltd.); SPE-12A solid-phase extraction device (Beijing Chengmeng Weiye Technology Co., Ltd.); benchtop high-speed refrigerated centrifuge (Hunan Hexi Instrument Equipment Co., Ltd.); Vortex-Genie 2 vortex mixer (Aika (Guangzhou) Instrument Equipment Co., Ltd.); high-performance liquid chromatograph (Shimadzu (China) Co., Ltd.).

[0040] 1.3 Experimental Methods

[0041] 1.3.1 Sample Pretreatment

[0042] One hundred and four apple samples were collected and kept in a controlled atmosphere environment of 7°C, 5% oxygen concentration, and 95% relative humidity. The samples were pretreated according to the experimental methods for polyphenols, ascorbic acid, and organic acids, and then stored at -20°C for later use. The samples of Gansu Jingning Red Fuji apples, Shandong Qixia Red Fuji apples, Shaanxi Luochuan Red Fuji apples, Gansu Xifeng Red Fuji apples, and Gansu Qin'an Red Fuji apples were numbered 1, 2, 3, 4, and 5, respectively.

[0043] 1.3.2 Detection of organic acids, polyphenols and ascorbic acid in Fuji apples

[0044] Determination of organic acids: Refer to GB5009.157-2016 "National Food Safety Standard - Determination of Organic Acids in Food"; Determination of oxalic acid in organic acids: The method described in [Guo Yan, Liang Jun, Li Minmin, et al. Determination of organic acids in apple fruit by high performance liquid chromatography [J]. Food Science, 2012, v.33; No.423(02):227-230.] was slightly modified; Determination of apple polyphenols: Refer to NYT2795-2015 "Determination of major phenolic substances in apple by high performance liquid chromatography"; Determination of ascorbic acid: Refer to Method I of GB5009.86-2016 "National Food Safety Standard - Determination of ascorbic acid in food".

[0045] 1.4 Data Statistical Methods

[0046] Data variance analysis was performed using SPSS 26 software, PCA was performed using Canoco 5 software, PLS-DA was performed using SIMCA-P 14.1 software, and LDA was performed using SPSS 26 software.

[0047] 2 Results and Analysis

[0048] The determination of organic acids in apples revealed that isocitric acid, glyceric acid, glyoxylic acid, oxaloacetic acid, and quinic acid were not detected, while polyphenols such as epicatechin, quercetin, gallic acid, epicatechin acid, p-coumaric acid, and dihydrochalcone were also not detected.

[0049] 2.1 HPLC fingerprint of organic acids, polyphenols and ascorbic acid in apples

[0050] like Figure 1 , 2 As shown in Figure 3, the superposition of HPLC chromatograms of organic acids, polyphenols, and ascorbic acid in 104 batches of apple samples constitutes the HPLC fingerprint of organic acids, polyphenols, and ascorbic acid in apple samples. The wavelength selected for organic acids was 210 nm, for polyphenols it was 320 nm, and for ascorbic acid it was 245 nm. The relative standard deviation (RSD) of the peak area of ​​organic acid chromatograms in the 104 batches of apple samples ranged from 0.2% to 4.8%, for polyphenol peak areas it ranged from 0.3% to 4.2%, and for ascorbic acid peak areas it ranged from 0.2% to 3.5%, indicating that the precision and reproducibility of the method meet the requirements for fingerprint determination. Comparison showed that the fingerprints of organic acids, polyphenols, and ascorbic acid in apples had high similarity, indicating that the HPLC fingerprints of apples from different origins were relatively stable. However, analysis of variance revealed differences in the content of organic acids and polyphenols in apple samples from different origins.

[0051] 2.2 Comparative Analysis of the Content of Organic Acids, Polyphenols and Ascorbic Acid in Apples

[0052] As shown in Tables 1, 2, and 3, the malic acid content in the tested Fuji apples was the highest, ranging from 2.7 to 3.2 g / kg. This was followed by oxalic acid and tartaric acid, with oxalic acid content ranging from 0.30 to 0.35 g / kg and tartaric acid content ranging from 0.13 to 0.19 g / kg. The contents of catechin, phlorizin, chlorogenic acid, and rutin were relatively low among all organic components. Among the tested apples from Jingning, phlorizin had the lowest content, around 1.40 mg / kg. The content of these organic components, from highest to lowest, was: malic acid > oxalic acid > tartaric acid > citric acid > ascorbic acid > succinic acid > rutin > catechin > chlorogenic acid > phlorizin. Among the tested Red Fuji apples from Qixia, Shandong, malic acid content was the lowest among the five producing areas, around 2.7 g / kg. Unlike Jingning apples, rutin content was higher than succinic acid content. Among the tested Red Fuji apples from Luochuan, Shaanxi, malic acid content was relatively high among the five producing areas, around 3.2 g / kg, while phlorizin content was the lowest, around 3.84 mg / kg. Among the tested Red Fuji apples from Xifeng, Gansu, unlike Jingning apples, phlorizin content was higher than chlorogenic acid. Among the tested Red Fuji apples from Qin'an, Gansu, chlorogenic acid content was higher than phlorizin content, which was higher than catechin content. Among the organic components tested in the Red Fuji apples, the contents of oxalic acid, succinic acid, citric acid, phlorizin, chlorogenic acid, and rutin showed differences at the 1% level, while tartaric acid and malic acid showed differences at the 5% level. Catechins and ascorbic acid showed no significant differences. Succinic acid had the highest content in Jingning apples, at around 0.028 g / kg; phlorizin had the lowest content in Jingning apples, at around 1.40 mg / kg; and rutin had the highest content in Qixia apples from Shandong, at around 20.62 mg / kg. These differences may be related to the apple-growing environment, such as the climate, soil environment, and orchard management.

[0053] Table 1 Comparative Analysis of Organic Acid Content in Red Fuji Apples

[0054]

[0055] Note: *** and ** represent the 1% and 5% significance levels, respectively.

[0056] Table 2 Comparative Analysis of Polyphenol Content in Red Fuji Apples

[0057]

[0058] Note: *** represents a 1% significance level.

[0059] Table 3 Comparative Analysis of Ascorbic Acid Content in Red Fuji Apples

[0060]

[0061]

[0062] 2.3 Principal Component Analysis of Organic Components in Fuji Apples

[0063] Bi-standardization analysis is a scientific mapping method that reflects a two-dimensional representation of a series of elements and the relationships between these elements. PCA was performed on 10 organic components of apple samples from five different production areas. Figure 4 The results show that the first two principal components contribute 69.71% of the total variance, PC1 contributes 49.15%, and PC2 contributes 20.56%. In the figure, Jingning apples are distinguished from apples from other regions. On PC1, non-Jingning apple samples have higher scores, all positive. Rutin, phlorizin, and chlorogenic acid have large loadings on PC1, clearly distinguishing non-Jingning apples from Jingning apples. Succinic acid has a negative loading on PC1, distinguishing Jingning apples from other apple samples. Secondly, on PC2, Jingning apple samples mostly have positive scores, while non-Jingning apple samples all have negative scores. Malic acid has the largest negative loading on PC2, distinguishing Jingning apple samples from other apple samples. Ascorbic acid and catechins have small loadings on both PC1 and PC2, contributing little to the principal components, consistent with the ANOVA results.

[0064] 2.4 Partial Least Squares Discriminant Analysis

[0065] The contents of eight significantly different organic components (oxalic acid, succinic acid, tartaric acid, citric acid, malic acid, phlorizin, chlorogenic acid, and rutin) from 104 samples were imported into SIMCA-P 14.1 software, and PLS-DA analysis was selected to generate scatter plots. Figure 5 The PLS-DA score plot shows that, within the 95% confidence interval, the PLS-DA model has a cumulative variance explained (R² X) of 0.975 for the independent variable, a cumulative variance explained (R² Y) of 0.661 for the dependent variable, and a model predictive value (Q²) of 0.576. The cumulative variance explained and model predictive values ​​are relatively low. The plot shows overlap between apple samples from different origins, and apple samples from the same origin are dispersed. This may be due to significant individual differences among apple samples, differences in fruit tree varieties, and differences in the production environment. This indicates that the model can effectively distinguish apple samples to a certain extent.

[0066] 2.5 Linear discrimination of organic components in Fuji apples

[0067] Based on the above results, eight organic components were selected—oxalic acid, succinic acid, tartaric acid, citric acid, malic acid, phlorizin, chlorogenic acid, and rutin—to establish an apple origin discrimination model.

[0068] Y 甘肃静宁 =-92.464+4.235X根皮苷 +4.394X 绿原酸 +0.489X 芦丁 +0.346X 草酸 +0.510X 琥珀酸

[0069] +0.007X 酒石酸 -0.052X 柠檬酸 +0.008 苹果酸

[0070] Y 山东栖霞 =-149.586+10.464X 根皮苷 +5.893X 绿原酸 +4.800X 芦丁 +0.282X 草酸 -0.509X 琥珀

[0071] 酸 -0.106X 酒石酸 +0.396X 柠檬酸 +0.012X 苹果酸

[0072] Y 陕西洛川 =-117.187+12.067X 根皮苷 +5.481X 绿原酸 +0.880X 芦丁 +0.280X 草酸 -0.345X 琥珀

[0073] 酸 +0.007X 酒石酸 +0.467X 柠檬酸 +0.010X 苹果酸

[0074] Y 甘肃西峰 =-115.644+15.814X 根皮苷 +5.889X 绿原酸 +0.852X 芦丁 +0.279X 草酸 -0.182X 琥珀

[0075] 酸 -0.138X 酒石酸 +0.463X 柠檬酸 +0.011X 苹果酸

[0076] Y 甘肃秦安 =-142.427+17.642X 根皮苷 +8.653X绿原酸 +0.033X 芦丁 +0.321X 草酸 +0.272X 琥珀

[0077] 酸 -0.114X 酒石酸 +0.063X 柠檬酸 +0.013X 苹果酸

[0078] Y 甘肃静宁 Y 山东栖霞 Y 陕西洛川 Y 甘肃西峰 Y 甘肃秦安 —Discriminative function values ​​for Fuji apples from Jingning, Gansu; Qixia, Shandong; Luochuan, Shaanxi; Xifeng, Gansu; and Qin'an, Gansu.

[0079] X 根皮苷 X 绿原酸 X 芦丁 X 草酸 X 琥珀酸 X 酒石酸 X 柠檬酸 X 苹果酸 —Contents of phlorizin, chlorogenic acid, rutin, oxalic acid, succinic acid, tartaric acid, citric acid and malic acid in apples, mg / kg.

[0080] The principle of linear discriminant analysis lies in establishing different models between data classes. Generally, several quantitative features labeled with classification groups are projected onto a straight line. The coefficients of the linear discriminant function are determined by the maximum or minimum distance between sample classes when the sample projection values ​​on the line are maximized or minimized. The linear discriminant function has the best separability in its classification effect.

[0081] In the apple origin determination model, the measured data is substituted into the discriminant function, and the origin determination is the group with the highest discriminant function value. Figure 6 As can be seen from the discriminant function score graph, apple samples from different origins can be clearly distinguished, especially Jingning apples, which show significant differences from apples from other origins. Table 4 shows that some apple samples from Xifeng, Gansu, were misclassified as originating from Qin'an, Gansu, and Luochuan, Shaanxi, while some apple samples from Qin'an, Gansu, were misclassified as originating from Xifeng, Gansu, and Luochuan, Shaanxi. This may be because the proportion of similar samples in the training set is relatively small. 98.1% of the apples were correctly classified, and 95.2% of the cross-validated apples were correctly classified. The model evaluation results indicate that linear discriminant analysis can determine the origin of apple samples to a certain extent.

[0082] Table 4 Model Evaluation Results a,c

[0083]

[0084] Note: a. 98.1% of the original grouped cases were correctly classified. b. Cross-validation was performed only for cases in the analysis. In cross-validation, each case was classified by functions derived from all other cases. c. 95.2% of the grouped cases that underwent cross-validation were correctly classified.

[0085] 3 Results

[0086] A differential analysis based on the organic components of apples revealed that there are indeed differences between Fuji apples from different origins. High-performance liquid chromatography (HPLC) was used to determine 21 organic components, obtaining HPLC fingerprints of organic acids, polyphenols, and ascorbic acid from the apple samples. After screening, eight organic components with significant differences in apple samples were identified. Principal component bipolar analysis clearly distinguished Jingning apples from apples from other origins. Partial least squares discriminant analysis was performed, and this model can effectively distinguish apple samples from five production areas to a certain extent. Linear discriminant analysis can also determine the origin of apple samples to a certain extent. This is because apples are influenced not only by genetic factors but also by the climate, soil, and fertilization conditions of their production area. The differences in the organic components of apples reflect these internal and external factors to a certain extent.

[0087] Research has shown that a discriminant function based on eight organic components—oxalic acid, succinic acid, tartaric acid, citric acid, malic acid, phlorizin, chlorogenic acid, and rutin—can, to a certain extent, identify the origin of Fuji apples, achieving a classification accuracy of 95.2%. Theoretically, this invention will provide a foundation for differentiating Jingning apples from other Fuji apple origins. Furthermore, the linear discriminant model in this invention can be applied in practice, providing technical support for tracing the origin of Jingning apples and controlling apple quality.

[0088] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A method for determining the origin of Fuji apples based on organic component analysis, characterized in that: Includes the following steps: S1. Construct linear discriminant functions for the organic components oxalic acid, succinic acid, tartaric acid, citric acid, malic acid, phlorizin, chlorogenic acid, and rutin: Y 甘肃静宁 =-92.464+4.235X 根皮苷 +4.394X 绿原酸 +0.489X 芦丁 +0.346X 草酸 +0.510X 琥珀酸 +0.007X 酒石酸 -0.052X 柠檬酸 +0.008 苹果酸 ; Y 山东栖霞 =-149.586+10.464X 根皮苷 +5.893X 绿原酸 +4.800X 芦丁 +0.282X 草酸 -0.509X 琥珀酸 -0.106X 酒石酸 +0.396X 柠檬酸 +0.012X 苹果酸 ; Y 陕西洛川 =-117.187+12.067X 根皮苷 +5.481X 绿原酸 +0.880X 芦丁 +0.280X 草酸 -0.345X 琥珀酸 +0.007X 酒石酸 +0.467X 柠檬酸 +0.010X 苹果酸 ; Y 甘肃西峰 =-115.644+15.814X 根皮苷 +5.889X 绿原酸 +0.852X 芦丁 +0.279X 草酸 -0.182X 琥珀酸 -0.138X 酒石酸 +0.463X 柠檬酸 +0.011X 苹果酸 ; Y 甘肃秦安 =-142.427+17.642X 根皮苷 +8.653X 绿原酸 +0.033X 芦丁 +0.321X 草酸 +0.272X 琥珀酸 -0.114X 酒石酸 +0.063X 柠檬酸 +0.013X 苹果酸 ; In the formula, Y 甘肃静宁 Y 山东栖霞 Y 陕西洛川 Y 甘肃西峰 Y 甘肃秦安 —Discriminant function values ​​for Fuji apples from Jingning (Gansu), Qixia (Shandong), Luochuan (Shaanxi), Xifeng (Gansu), and Qin'an (Gansu); X 根皮苷 X 绿原酸 X 芦丁 X 草酸 X 琥珀酸 X 酒石酸 X 柠檬酸 X 苹果酸 —Contents of phlorizin, chlorogenic acid, rutin, oxalic acid, succinic acid, tartaric acid, citric acid and malic acid in apples, mg / kg; S2. Obtain the contents of oxalic acid, succinic acid, tartaric acid, citric acid, malic acid, phlorizin, chlorogenic acid and rutin in the apple sample to be tested; S3. The contents of oxalic acid, succinic acid, tartaric acid, citric acid, malic acid, phlorizin, chlorogenic acid and rutin in the obtained apple samples to be tested are entered into the linear discriminant function, and the group with the largest discriminant function value is taken as its place of origin detection result.

2. The method for determining the origin of Fuji apples based on organic component analysis as described in claim 1, characterized in that: Step S1 includes the following steps: S11. Based on the national standard, 21 organic components of Red Fuji apples from five production areas—Jingning in Gansu, Qixia in Shandong, Luochuan in Shaanxi, Xifeng in Gansu, and Qin'an in Gansu—were determined using high-performance liquid chromatography (HPLC). HPLC fingerprints of apple organic acids, polyphenols, and ascorbic acid were obtained, and eight organic components with significant differences were screened out: oxalic acid, succinic acid, tartaric acid, citric acid, malic acid, phlorizin, chlorogenic acid, and rutin. S12. Project the features of oxalic acid, succinic acid, tartaric acid, citric acid, malic acid, phlorizin, chlorogenic acid, and rutin, which are labeled with classification groups, onto a straight line. Determine the coefficients of the linear discriminant function by finding that the sample projection values ​​on this line reach the maximum or minimum distance between sample categories. Establish the linear discriminant function.

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