Method for rapidly identifying rose flower cakes from different producing areas

Abstract

The invention discloses a method for quickly identifying rose flower cakes from different producing areas, which comprises the following steps: detecting volatile components of the rose flower cakes by adopting a headspace gas phase-ion mobility spectrometry technology to obtain GC-IMS sample data, and carrying out statistical analysis on the GC-IMS sample data through VOCal analysis software, a Report plug-in and a Galley Plot plug-in of an instrument, the GC-IMS fingerprint spectrums of the volatile aroma components of the rose flower cakes from different producing areas are obtained, so that the rose flower cakes are rapidly identified. According to the method, the GC-IMS technology is applied to carry out collection and trace analysis on the complex volatile substances in the rose flower cakes from different producing areas, comprehensive fingerprint information is provided for identification of the rose flower cakes, rapid and accurate distinguishing of the rose flower cakes from different producing areas is achieved, compared with a traditional analysis method, the method is simple and effective, consumed time is greatly shortened, and the method is suitable for large-scale popularization and application. The method has high sensitivity, and provides theoretical basis and data support for rapid identification of rose flower cakes from different producing areas.

Description

Technical Field

[0001] This invention relates to a method for rapidly identifying roses from different origins to make rose petal cakes based on gas phase-ion mobility spectrometry (GC-IMS) technology, belonging to the fields of food science and analytical chemistry. Background Technology

[0002] The rose is a perennial deciduous shrub belonging to the genus Rosa in the family Rosaceae. According to the *Compendium of Materia Medica*, roses are warm in nature and sweet in taste, possessing liver-benefiting, spleen-strengthening, and stomach-nourishing effects, and have high medicinal and economic value. Roses have a long history of cultivation in my country, and are now cultivated throughout the country. Roses have a wide range of uses, including horticultural decoration, food processing, cosmetics manufacturing, and medicinal applications. In horticulture, roses are used to beautify the environment and enhance landscape effects. In the food industry, rose petals can be used to make jams, teas, desserts, etc., adding aroma and flavor to food. In the cosmetics industry, rose essential oil is used to make perfumes and skincare products, favored by consumers for its unique fragrance and skincare effects. Medicinally, roses contain various active ingredients, such as vitamin C, glucose, fructose, and citric acid, which have antioxidant, anti-inflammatory, and antibacterial effects. In addition, roses are rich in volatile aromatic components, such as geraniol and citronellol, which are widely used in aromatherapy to help relieve stress and anxiety. Rose petal cakes are a traditional Chinese pastry made by wrapping fresh or dried rose petals into a flaky pastry and then baking it. They not only carry rich historical and cultural connotations but also attract people's taste buds with their unique taste and aroma. However, due to factors such as climate, soil, and cultivation methods, roses from different origins have different quality characteristics. These differences ultimately manifest in the flavor of rose petal cakes, significantly affecting their market competitiveness. Therefore, a method for quickly identifying fresh rose petal cakes from different origins is needed.

[0003] Gas chromatography-ion mobility spectrometry (GC-IMS) is a technique that combines gas chromatography and ion mobility spectrometry. It combines the advantages of high resolution and extremely high sensitivity of both GC and IMS, providing a foundation for the qualitative and quantitative analysis of trace volatile organic compounds and the analysis of certain isomers. Given the significant advantages of GC-IMS, this study used GC-IMS to collect and analyze trace amounts of volatile components in rose petal cakes from different origins. This provides comprehensive fingerprint information for differentiating rose petal cakes, enabling rapid and accurate identification of rose petal cakes from different origins, and providing theoretical basis and data support for controlling the production of rose petal cakes and improving their flavor and quality. Summary of the Invention

[0004] In order to overcome the shortcomings of existing analytical techniques, the purpose of this invention is to provide a rapid and effective identification method for rose petal cakes made from roses from different origins.

[0005] This invention provides a method for rapidly identifying rose petal cakes made from roses of different origins. The main technical principle and route is to use gas phase-ion mobility spectrometry to obtain the fingerprint spectrum of volatile components of rose petal cakes from different origins. By comparing the differences in the content of volatile substances, the rose petal cakes can be identified.

[0006] The steps are as follows: (1) Preparation of rose samples from different origins: The roses were purchased from local markets in Pingyin County, Jinan City, Shandong Province; Tongxu County, Kaifeng City, Henan Province; Moyu County, Hotan City, Xinjiang Uygur Autonomous Region; Anning City, Yunnan Province; and Yongdeng County, Lanzhou City, Gansu Province. The purchased roses were labeled as SD, HN, XJ, YN and GS, and three parallel samples were taken for each type. (2) The process of making rose petal cakes: Rose petal jam: Pick 300g of rose petals, wash and dry them, add 450g of white sugar, rub with your hands, add an appropriate amount of lemon juice and honey, put into a jar, seal and ferment for three days.

[0007] Rose filling: Stir-fry 75g of low-gluten flour over low heat until slightly yellow, then mix it with 125g of rose jam, 4g of cooked glutinous rice flour and 22g of lard. Divide the mixture into 5 equal portions, each weighing 35g, and refrigerate for later use.

[0008] For the oil-based dough and the shortening: Mix 60g of all-purpose flour with boiling water until it forms clumps. Add 8g of sugar and 26g of lard, and knead into a smooth dough. Divide the dough into 5 equal portions and refrigerate for 1 hour. Mix 45g of cake flour with 22g of lard to form a dough. Divide the dough into 5 equal portions and refrigerate as well.

[0009] Wrap the oil-based dough around the oil-based filling, roll and fold twice, cover with plastic wrap and let rest for 15 minutes each time. Preheat oven to 190 degrees Celsius. Wrap the rose filling in the dough, using the thumb-and-screw method to round it, and gently press it into a round cake shape with your palm. Bake in a conventional oven at 180 degrees Celsius for 38 minutes, covering with aluminum foil if the top browns too quickly. (3) Gas-ion mobility spectrometry (GC-IMS) detection process: Gas chromatography-ion mobility spectrometry was used to detect rose petal cakes from different origins. The analysis time was 20 min to obtain GC-IMS sample data. SD samples were used as controls. The GC-IMS sample data were statistically analyzed using the instrument’s built-in VOCal analysis software and Reporter and Gallery Plot plugins. The NIST and IMS databases built into the software were used to perform qualitative analysis of the substances to obtain fingerprint spectra of volatile aroma components of rose petal cakes made from roses from different origins. (4) Selection of spectral feature regions: The feature value regions on the fingerprint information spectrum obtained in step (3) are extracted by comparison method. The comparison method is to select the spectral feature regions of volatile substances with obvious color changes or large peak intensity differences in the fingerprint information spectrum based on the color difference or peak intensity signal of the feature substances in the fingerprint information spectrum. (5) Principal component analysis: Using the Dynamic PCA plugin, cluster analysis and similarity analysis of rose petal cake samples were performed, combined with fingerprint spectrum, to quickly identify the volatile components of rose petal cakes from different origins.

[0010] The selection of spectral feature regions in step (4) is achieved by using a qualitative method to compare the differences in peak intensity signals of each substance in the database, thereby selecting the regions of substances with significant differences as spectral feature regions.

[0011] Further, the determination conditions for gas chromatography-ion mobility spectrometry (GC-IMS) are as follows: Gas chromatography-ion mobility spectrometry (GC-IMS) unit analysis conditions: MAX-WAX column, 30 meter, 0.53 mm ID, 1.0 μm; column temperature 60 ℃; carrier gas N2; IMS temperature 60 ℃. Automated headspace sampling (AGS) unit analysis conditions: injection volume 100 μL; incubation time 15 min; incubation temperature 80 ℃; injection needle temperature 85 ℃; incubation speed 500 rpm.

[0012] The rose petal cake contains 65 kinds of volatile aroma substances, specifically: propanol, propyl butyrate, butyl butyrate, acetic acid, propanol, hexanol, 2-butanone, ethyl alcohol, propanol, ethyl acetate, butyraldehyde, 2,6-dimethyl-4-heptanone, cis-3-hexenyl acetate, ethyl lactate, 2-methylbutanol, propyl acetate, cyclopentanone, furfural, L-rosinone, 3-hydroxy-2-butanone. Allyl heptaate, benzaldehyde, butyl acetate, 2-methyl-1-propanol, butanol, acetone, butyl propionate, ethyl butyrate, n-nonanal, isoamyl acetate, 2-butanol, n-pentanol, pentanal, cis-4-heptenal, cis-4-heptenal, heptenal, n-nonanal, 1-octene, trans-2-heptenal, 2-hexenal, linalool, n-hexanol, α-pinene, 3-methyl-1-butanol, 1-penten-3-one.

[0013] The beneficial effects of this invention are: A simple and rapid gas chromatography-ion mobility spectrometry (GC-IMS) technique was employed to analyze the volatile components of fresh rose petals from different origins. This technique allows for the identification of characteristic regions of the sample based on retention time and ion migration time without requiring knowledge of specific volatile substances. Principal component analysis combined with fingerprinting enables rapid identification of fresh rose petals from different origins. This method is simple to operate, highly sensitive, stable, has a short sample detection time, and requires no complex sample pretreatment, making it highly valuable for application. Attached Figure Description

[0014] Figure 1 This is a qualitative analysis chromatogram of volatile organic compounds in rose petal cakes (sample source: SD). Note: Figure 1 Each point represents a volatile flavor compound. The red vertical line at the x-axis (1.0) represents the reaction ion peak (RIP), with most points concentrated in the retention time of 100–450 s and drift times ranging from 1 to 1.75 s. The marked points are identified compounds. In the GC×IMS library search, 71 signal peaks and 65 compounds were identified in the built-in NIST and IMS databases. Points 39, 50, 35, 61, 62, and 64 are unidentified compounds.

[0015] Figure 2 These are the original three-dimensional images of rose petal cakes from different origins. Note: The vertical axis represents the retention time by gas chromatography, and the horizontal axis represents the ion migration time of volatile compounds. From Figure 2 It can be seen that the peak signal distribution of all samples is similar, but the peak signal intensity of each sample is different, which indicates that the content of volatile flavor substances in the flower cake samples made from roses from different origins is different.

[0016] Figure 3This is a chromatogram comparing the volatile organic compounds (VOCs) of the SD sample with those of other rose petal cake samples. Note: The red vertical line on the horizontal axis represents the RIP peak (reactive ion peak), the vertical axis represents the retention time (s) in gas chromatography, and the horizontal axis represents the ion migration time. Each point on either side of the RIP peak represents a VOC. VOCs vary among different samples. To more clearly compare these differences, a difference comparison mode can be used: select the spectrum of one sample as a reference, and subtract the reference from the spectra of the other samples. If the VOCs of the two samples are identical, the background after subtraction will be white; red indicates that the concentration of the substance is higher than the reference, and blue indicates that the concentration of the substance is lower than the reference.

[0017] Figure 4 This is a gallery plot of rose petal cakes from different origins.

[0018] Figure 5 Principal component analysis of the signal intensity of rose petal cakes from different origins. Note: The horizontal axis represents principal component 1 with a contribution rate of 45%, and the vertical axis represents principal component 2 with a contribution rate of 29%. Each point represents one sample, and each sample has three parallel samples.

[0019] Figure 6 This is a spectral analysis of Euclidean distances between rose petal cakes from different origins. Note: Figure 6 The nearest neighbor map, also known as the Euclidean distance map, is used to distinguish sample similarity through Euclidean distance analysis, combined with PCA analysis for sample classification. Closer sample distances indicate smaller differences and higher similarity. Detailed Implementation

[0020] To better understand the present invention, the following embodiments and accompanying drawings further illustrate the content of the present invention. However, the content of the present invention is not limited to the following embodiments, and the embodiments should not be regarded as limiting the scope of protection of the present invention.

[0021] 1. Materials and Methods 1.1 Materials and Equipment Materials: The roses were sourced from Pingyin County, Jinan City, Shandong Province; Tongxu County, Kaifeng City, Henan Province; Moyu County, Hotan City, Xinjiang Uygur Autonomous Region; Anning City, Yunnan Province; and Yongdeng County, Lanzhou City, Gansu Province, and were purchased from local markets.

[0022] Equipment: FlavorSpec® Flavor Analyzer and Quality Control System (equipped with an automated headspace sampler, VOCal analysis software, Reporter plugin, Gallery Plot plugin and Dynamic PCA plugin), GAS GmbH, Germany.

[0023] 1.2 GC-IMS Measurement Conditions: Flavor analysis was performed using a FlavorSpec® flavor analyzer. 1.0 g of sample was weighed and placed in a 20 mL headspace vial, incubated at 80 °C for 15 minutes, and then injected. Gas chromatography-ion mobility spectrometry (GC-IMS) unit analysis conditions: MAX-WAX column, 30 meter, 0.53 mm ID, 1.0 μm; column temperature 60 °C; carrier gas N2; IMS temperature 60 °C. Automated headspace sampling (AHS) unit analysis conditions: injection volume 100 μL; incubation time 15 min; incubation temperature 80 °C; injection needle temperature 85 °C; incubation speed 500 rpm.

[0024] 1.3 Data Processing The differential spectra of volatile organic compounds in the samples were obtained by analyzing the VOCal, Reporter plugin and Gallery Plot plugin, and a matching matrix was established. The substances were qualitatively analyzed using the National Institute of Standards and Technology (NIST) database and IMS database, and then Principal Components Analysis (PCA) was performed.

[0025] 2. Results and Analysis 2.1 Ion migration map of volatile aroma compounds in rose petal cakes GC-IMS fingerprint of volatile aroma components in rose petal cakes, see [link / reference]. Figure 1 .

[0026] Figure 1 The vertical axis represents the gas phase retention time (Rt), and the horizontal axis represents the drift time (Dt). The vertical line on the left side of the spectrum represents the reactant ion peak (RIP). Each point to the right of the RIP represents a volatile substance. Darker colors indicate higher concentrations. The entire spectrum represents the headspace composition of the sample. The main aroma compounds in the rose petal cake were determined by ion migration time and retention index, as shown in Table 1. The table shows that 65 volatile aroma compounds were identified in the rose petal cake, including 20 aldehydes, 16 esters, 15 alcohols, 9 ketones, 2 hydrocarbons, 2 acids, and 1 heterocyclic compound.

[0027] Table 1. Main volatile aroma compounds in rose petal cakes serial number compound CAS# Molecular formula MW RI Rt[sec] Dt [RIP relative] Notes 1 Acetic acid C64197 C2H4O2 60.1 1488.8 1105.77 1.05531 monomer 2 furanaldehyde C98011 C5H4O2 96.1 1486.4 1097.824 1.09204 3 nonanal C124196 C9H18O 142.2 1402.7 850.708 1.4869 4 n-Hexyl alcohol C111273 C6H14O 102.2 1367.7 764.893 1.33539 5 Ethyl lactate C97643 C5H10O3 118.1 1357.3 741.055 1.15173 6 cis-3-hexenyl acetate C3681718 C8H14O2 142.2 1310.9 643.321 1.04245 7 acetic acid C64197 C2H4O2 60.1 1488.3 1104.181 1.15816 Dimer 8 3-Hydroxy-2-Butanone C513860 C4H8O2 88.1 1295.5 613.922 1.06174 monomer 9 3-Hydroxy-2-Butanone C513860 C4H8O2 88.1 1295.5 613.922 1.35008 Dimer 10 n-Pentanol C71410 C5H12O 88.1 1260.5 558.3 1.261 monomer 11 2,6-Dimethyl-4-heptanone C108838 C9H18O 142.2 1240.5 528.901 1.34549 12 n-Pentanol C71410 C5H12O 88.1 1261.5 559.89 1.52914 Dimer 13 cis-4-heptenal C6728310 C7H12O 112.2 1236 522.544 1.15816 14 2-Hexenal C6728263 C6H10O 98.1 1226.9 509.831 1.19305 15 3-Methyl-1-butanol C123513 C5H12O 88.1 1215.8 494.734 1.2509 monomer 16 heptanal C111717 C7H14O 114.2 1194.5 466.923 1.33722 monomer 17 heptanal C111717 C7H14O 114.2 1195.1 467.718 1.7229 Dimer 18 propyl butyrate C105668 C7H14O2 130.2 1185.7 456.594 1.27202 19 Butyl butyrate C109217 C8H16O2 144.2 1225.2 507.447 1.34916 20 3-Methyl-1-butanol C123513 C5H12O 88.1 1215.8 494.734 1.5071 Dimer 21 Octal C124130 C8H16O 128.2 1299 620.569 1.41354 22 Butanol C71363 C4H10O 74.1 1153 420.736 1.1857 monomer 23 Butanol C71363 C4H10O 74.1 1153 420.736 1.39184 Dimer 24 2-Ethylpropenal C1576870 C5H8O 84.1 1142.5 409.86 1.1137 monomer 25 2-Ethylpropenal C1576870 C5H8O 84.1 1142.1 409.407 1.38099 Dimer 26 Cyclopentanone C120923 C5H8O 84.1 1136.3 403.516 1.10976 monomer 27 2-Methyl-1-propanol C78831 C4H10O 74.1 1102.2 370.522 1.17603 monomer 28 2-Methyl-1-propanol C78831 C4H10O 74.1 1101.9 370.292 1.37562 Dimer 29 hexanol C66251 C6H12O 100.2 1096.7 365.465 1.26249 monomer 30 hexanol C66251 C6H12O 100.2 1096.7 365.465 1.58491 Dimer 31 Butyl acetate C123864 C6H12O2 116.2 1084.1 355.581 1.25118 monomer 32 Butyl acetate C123864 C6H12O2 116.2 1084.7 356.041 1.64713 Dimer 33 propanol C71238 C3H8O 60.1 1048.7 329.148 1.11462 monomer 34 propanol C71238 C3H8O 60.1 1048.1 328.688 1.25765 Dimer 35 α-pinene C80568 C10H16 136.2 1032.4 317.655 1.22936 36 2-Butanol C78922 C4H10O 74.1 1032.7 317.885 1.3336 Dimer 37 1-Penten-3-one C1629589 C5H8O 84.1 1025 312.598 1.08714 38 Isoamyl acetate C123922 C7H14O2 130.2 1131.6 398.794 1.31906 39 Ethyl butyrate C105544 C6H12O2 116.2 1048.1 328.688 1.21401 monomer 40 Ethyl butyrate C105544 C6H12O2 116.2 1047.7 328.458 1.58734 Dimer 41 2-Butanol C78922 C4H10O 74.1 1032.7 317.885 1.14856 monomer 42 Cyclopentanone C120923 C5H8O 84.1 1136.6 403.851 1.34411 Dimer 43 L-rosine C3033236 C10H18O 154.3 1090.3 360.408 1.39098 44 Propyl acetate C109604 C5H10O2 102.1 988.4 289.829 1.17256 monomer 45 Propyl acetate C109604 C5H10O2 102.1 985.7 288.557 1.50166 Dimer 46 Ethyl alcohol C64175 C2H6O 46.1 937 266.64 1.14193 47 2-Methylbutanal C96173 C5H10O 86.1 919.8 259.287 1.16381 monomer 48 2-Methylbutanal C96173 C5H10O 86.1 920.1 259.428 1.42376 Dimer 49 2-Butanone C78933 C4H8O 72.1 909.2 254.903 1.06928 monomer 50 2-Butanone C78933 C4H8O 72.1 907.9 254.338 1.26271 Dimer 51 Ethyl acetate C141786 C4H8O2 88.1 891.5 247.692 1.10342 monomer 52 Ethyl acetate C141786 C4H8O2 88.1 891.2 247.551 1.35549 Dimer 53 acetone C67641 C3H6O 58.1 838.2 227.189 1.13055 54 Butyraldehyde C123728 C4H8O 72.1 832.5 225.068 1.29685 Dimer 55 Butyraldehyde C123728 C4H8O 72.1 832.8 225.21 1.10517 monomer 56 propionaldehyde C123386 C3H6O 58.1 819.9 220.543 1.04915 monomer 57 propionaldehyde C123386 C3H6O 58.1 819.9 220.543 1.15681 Dimer 58 Pentanal C110623 C5H10O 86.1 997 294.071 1.44302 59 1-Octenene C111660 C8H16 112.2 846.6 230.3 1.16994 60 trans-2-heptenal C18829555 C7H12O 112.2 1331.1 684.162 1.26905 61 Butyl propionate C590012 C7H14O2 130.2 1149.3 416.789 1.2956 62 Linalool C78706 C10H18O 154.3 1596.5 1535.104 1.24175 63 benzaldehyde C100527 C7H6O 106.1 1532.2 1262.121 1.16192 64 Allyl heptaate C142198 C10H18O2 170.3 1145.8 413.21 1.45081 monomer 65 Allyl heptaate C142198 C10H18O2 170.3 1146 413.4 1.98696 Dimer 2.2 Comparison of fingerprint spectra of volatile aroma compounds in fresh rose cakes from different origins GC-IMS three-dimensional fingerprints of fresh rose cakes from different origins are as follows: Figure 2 , Figure 3 and Figure 4 Through observation, it can be clearly seen that some substances, although having the same retention and drift times, show significant differences in their cumulative content. Based on the Gallery Plot plugin, ion peak diagrams of volatile aroma compounds in rose petal cakes with obvious variation patterns were screened (see...). Figure 4 There are 65 volatile aroma compounds in rose petal cakes, but their contents vary. The figure shows three rows per sample (each sample was replicated in triplicate), and each column represents the signal peaks of organic compounds (the same substances in different samples) at the same retention and drift times.

[0028] Depend on Figure 4 This allows for a very intuitive overall comparison and analysis of all samples. The substances shown in the boxes in the figure are the characteristic volatile components of each sample, and their content in each sample is significantly higher than in other samples. The substances shown in the boxes in the figure are the unique volatile components of each sample, and their content in each sample is significantly higher than in other samples. The compounds in the spectrum, from left to right, are: propanol (monomer), propanol (dimer), propyl butyrate, butyl butyrate, acetic acid (monomer), propanol (monomer), n-hexanol (monomer), 2-butanone (monomer), ethyl alcohol, propanol (monomer), ethyl acetate (monomer), butanol (monomer), 2,6-dimethyl-4-heptanone, cis-3-hexenyl acetate, ethyl lactate, butanol (dimer), 2-methylbutanol (monomer), propyl acetate (monomer), cyclopentanone (monomer), furfural, cyclopentanone (dimer), propyl acetate (dimer), L-rosinone, 2-methylbutanol (dimer), 3-hydroxy-2-butanone (monomer), 3-hydroxy-2-butanone (dimer), allyl heptanate (dimer), butanol (dimer), butyl acetate (dimer), benzaldehyde, butyl acetate (monomer) Monomers), 2-methyl-1-propanol (monomer), butanol (monomer), ethyl acetate (dimer), acetone, butyl propionate, propionaldehyde (dimer), ethyl butyrate (monomer), n-nonanal, isoamyl acetate, 2-butanone (dimer), 2-butanol (monomer), n-pentanol (monomer), pentanol, ethyl butyrate (dimer), propanol (dimer), cis-4-heptenal, n-pentanol (dimer), cis-4-heptenal Enal, heptanal (dimer), heptanal (monomer), nonanal, hexanal (dimer), 1-octene, trans-2-heptenal, 2-hexenal, linalool, 3-methyl-1-butanol (dimer), 2-methyl-1-propanol (dimer), 2-butanol (dimer), hexanol, α-pinene, acetic acid (dimer), 3-methyl-1-butanol (monomer), n-pentanol (dimer), 1-penten-3-one Ten compounds, including cis-3-hexenyl acetate, ethyl lactate, and butyraldehyde, were present in high concentrations in sample SD. Five components, including allyl heptaate and 3-hydroxy-2-butanone, showed prominent peaks in sample group HN, indicating their high content in this sample group. Seven compounds, including butanol and butyl acetate, were present in prominent concentrations in sample group XJ. Sample groups YN and GS also showed components with higher content than the other sample groups in the figure. The volatile compounds contained in these characteristic regions may be the reason for the significant differences in the aroma of different rose petal cakes. Pentanol, hexanal, and heptenal have a rancid and oily smell at high concentrations, but have a pleasant grassy and fresh aroma at low concentrations. Pentanol can be regarded as a biomarker of rose petal aging, and its concentration increases with the extension of storage period.

[0029] 2.3 Principal Component Analysis of Volatile Aroma Compounds in Fresh Rose Cakes from Different Origins Principal component analysis of signal intensity obtained from rose petal cakes from different origins is shown below. Figure 5 , Figure 5 The distribution plots of the first two principal components determined by principal component analysis are presented, depicting the cumulative variance contributions of 45% and 29%, respectively. The principal component analysis results show the characteristic differences and clustering trends among the samples. The five types of flower cakes exhibit significant overall differentiation. In the YN sample, the differences between groups are more pronounced, located in the fourth quadrant. The YN sample points score higher on principal component 1 (PC1) than on principal component 2 (PC2), indicating a close correlation between PC1 and the YN sample. Based on the contribution analysis of PC1 and PC2, it can be concluded that the YN sample has more unique flavor characteristics. The HN and XJ groups are relatively close, indicating a high degree of similarity between these two groups; the SD, GS, and YN samples are all significantly different from the other samples, indicating substantial differences.

[0030] Figure 6The nearest neighbor analysis map of the samples was used to distinguish sample similarity through Euclidean distance, combined with PCA analysis for sample classification. Closer distances between samples indicate smaller differences and higher similarity. The map shows that the five samples are independent. The sample closest to sample SD is HN, indicating that HN is the most similar to sample SD; similarly, the sample closest to sample HN is XJ, indicating that XJ is the most similar to sample HN. This result indicates that the flavor compounds in flower cakes made from roses from different origins vary. For example, in terms of flower characteristics: Gansu Kushui roses have a darker color, which may make the flower cakes more vibrant in color, while double-petaled red roses have larger flowers and a stronger fragrance; these characteristics directly affect the appearance and aroma of the flower cakes. In terms of climate conditions: Yunnan, due to its unique natural conditions such as abundant sunshine and suitable temperatures, produces roses of excellent quality and rich fragrance. In terms of soil differences: different regions have different soil compositions and pH values, which may also lead to differences in the flavor compounds in rose petals.

[0031] This invention uses rose petals from five different origins—Shandong, Henan, Xinjiang Uygur Autonomous Region, Yunnan, and Gansu—as raw materials to produce rose petal cakes. Based on GC-IMS analysis, the volatile compounds among these petals are identified, utilizing their differences to distinguish rose petal cakes from different origins. Results show that the aroma characteristics of rose petal cakes from different origins are significantly different. Principal component analysis (PCA) can effectively differentiate them, with different samples existing in a relatively independent space, exhibiting good discriminative power. A fingerprint spectrum of volatile components in the rose petal cake samples was established using gas chromatography-ion mobility spectrometry (GC-IMS), thus establishing a simple, sensitive, and reliable method for identifying rose petal cakes. This method saves sample pretreatment steps, shortens analysis time, and provides a theoretical basis and data support for the large-scale identification of rose petal cakes.

Claims

1. A method for rapidly identifying fresh rose cakes from different origins, characterized in that, The steps are as follows: (1) Preparation of rose samples from different origins: The roses were produced in Pingyin County, Jinan City, Shandong Province; Tongxu County, Kaifeng City, Henan Province; Moyu County, Hotan City, Xinjiang Uygur Autonomous Region; Anning City, Yunnan Province; and Yongdeng County, Lanzhou City, Gansu Province. They were purchased from local markets. The purchased roses were labeled as SD, HN, XJ, YN and GS. Three parallel samples were taken for each type. (2) The process of making rose petal cakes: Rose petal jam: Pick 300g of rose petals, wash and dry them, add 450g of white sugar, rub with your hands, add an appropriate amount of lemon juice and honey, put into a jar, seal and ferment for three days; Rose filling: Stir-fry 75g of low-gluten flour over low heat until slightly yellow, then mix it with 125g of rose jam, 4g of cooked glutinous rice flour and 22g of lard. Divide the mixture into 5 equal portions, each weighing 35g, and refrigerate for later use. For the oil dough and oil filling: Mix 60g of all-purpose flour with boiling water until it forms clumps, add 8g of sugar and 26g of lard, knead into a smooth dough, divide into 5 equal portions, and refrigerate for 1 hour; mix 45g of low-gluten flour with 22g of lard into a dough, divide into 5 equal portions, and refrigerate as well. Wrap the oil dough with the oil filling, roll and fold twice, cover with plastic wrap and let rest for 15 minutes each time; preheat the oven to 190 degrees Celsius; wrap the dough with rose filling, use the tiger's mouth method to wrap it, round it, and gently press it into a round cake shape with your palm; bake in a conventional oven at 180 degrees Celsius for 38 minutes, and cover with aluminum foil if the color is satisfactory halfway through. (3) Gas-ion mobility spectrometry (GC-IMS) detection process: Gas chromatography-ion mobility spectrometry was used to detect rose petal cakes from different origins. The analysis time was 20 min to obtain GC-IMS sample data. SD samples were used as controls. The GC-IMS sample data were statistically analyzed using the instrument’s built-in VOCal analysis software and Reporter and Gallery Plot plugins. The NIST and IMS databases built into the software were used to perform qualitative analysis of the substances to obtain fingerprint spectra of volatile aroma components of rose petal cakes made from roses from different origins. (4) Selection of spectral feature regions: The feature value regions on the fingerprint information spectrum obtained in step (3) are extracted by comparison method. The comparison method is to select the spectral feature regions of volatile substances with obvious color changes or large peak intensity differences in the fingerprint information spectrum based on the color difference or peak intensity signal of the feature substances in the fingerprint information spectrum. (5) Principal component analysis: Using the Dynamic PCA plugin, cluster analysis and similarity analysis of rose petal cake samples were performed, combined with fingerprint spectrum, to quickly identify the volatile components of rose petal cakes from different origins.

2. The method for rapidly identifying rose petal cakes from different origins according to claim 1, characterized in that, Headspace gas chromatography (GC) conditions: 1.0 g sample was placed in a 20 mL headspace vial, incubated at 80 °C for 15 min, and then 100 μL was injected into the headspace for analysis using a gas chromatograph-ion mobility spectrometer. The carrier gas was 99.99% pure. N2 The injection needle temperature was 85℃, the chromatographic column was MAX-WAX, the stationary phase film thickness was 1μm, and the carrier gas flow rate was 0 ~ 2min, 2mL / min; 2 ~ 20min, 2 ~ 100 mL / min.

3. The method for rapidly identifying rose petal cakes from different origins as described in claim 2, characterized in that, The chromatographic column specifications are: 30m, ID: 0.53mm, 1.0μm.

4. The method for rapidly identifying rose petal cakes from different origins as described in claim 2, characterized in that, The ion mobility spectrometry measurement conditions were as follows: drift tube length: 98 mm; linear voltage inside the tube: 500 V / cm; drift gas... N2 Drift gas flow rate: 150 mL / min.

5. The method for rapidly identifying rose petal cakes from different origins as described in claim 1, characterized in that, All rose petal cake samples contained the same types of volatile substances, but the content of volatile aroma compounds varied greatly. The rose petal cakes contained 65 types of volatile aroma compounds, specifically: propanol, propyl butyrate, butyl butyrate, acetic acid, propanol, hexanol, 2-butanone, ethyl alcohol, propanol, ethyl acetate, butyraldehyde, 2,6-dimethyl-4-heptanone, cis-3-hexenyl acetate, ethyl lactate, 2-methylbutanal, propyl acetate, cyclopentanone, etc. Furanaldehyde, L-rosinone, 3-hydroxy-2-butanone, allyl heptanate, benzaldehyde, butyl acetate, 2-methyl-1-propanol, butanol, acetone, butyl propionate, ethyl butyrate, n-nonanal, isoamyl acetate, 2-butanol, n-pentanol, pentanal, cis-4-heptenal, cis-4-heptenal, heptenal, n-nonanal, 1-octene, trans-2-heptenal, 2-hexenal, linalool, n-hexanol, α-pinene, 3-methyl-1-butanol, 1-penten-3-one.

6. The method for rapidly identifying rose petal cakes from different origins as described in claim 1, characterized in that, The fingerprint spectra of volatile components of rose petal cakes from different origins were obtained by gas phase-ion mobility spectrometry. By comparing the differences in the content of volatile substances, rose petal cakes from different origins could be identified.

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