Skip to main content
NCBI home page
Food Chemistry: X logoLink to Food Chemistry: X
. 2025 Oct 2;31:103119. doi: 10.1016/j.fochx.2025.103119

Differential analysis of aroma fingerprints of roasted pork from different breeds: A complementary approach using GC-IMS, GC-O-MS, and GC×GC-MS

Xinhe Zhang a,1, Jingyu Li a,1, Wenjing Li a, Shuqi Zhao a, Chanchan Sun b, Chengyu Zeng c, Cheng Li d, Jiangyan Yu e, Fengxue Zhang a, Junke Li a, Huan Liu a,⁎
PMCID: PMC12519136  PMID: 41098763

Abstract

In China, limited knowledge of suitable pig breeds for roasting has hindered pork industrialization. The aroma profiles of roasted pork from different breeds were analyzed using sensory evaluation and multidimensional mass spectrometry. The distinct fingerprint differences were observed, with roasted meat from Min pigs (MIP) showing the greatest variation. Compared with Nanyang black pigs (NBP), Landrace pigs (LAP), Junan indigenous pigs (JUP), and Wujin pigs (WUP), the roasted pork from MIP exhibited the most intense sensory intensity, especially in terms of roasty, meaty, and fatty notes. Thirty-one key aroma compounds were identified, with pyrazines especially 3-ethyl-2,5-dimethylpyrazine, contributing most to the roasty aroma. The partial least squares discriminant analysis (PLS-DA) was an effective method for distinguishing the roasted pork from different breeds, with no overlap among the samples. Notably, the 3,5-diethyl-2-methylpyrazine emerged as a unique marker. This work provides a robust method for selecting pig breeds suited for roasting applications.

Keywords: Aroma fingerprint; Min pigs; PLS-DA; 3,5-diethyl-2-methylpyrazine; Marker

Highlights

  • •

    MIP samples showed the strongest aroma intensity, especially the roasty aroma.

  • •

    The most abundant types and contents of aroma compounds were detected in MIP samples.

  • •

    Pyrazines, aldehydes, and alcohols were predominant aroma compounds in roasted pork.

  • •

    3,5-Diethyl-2-methylpyrazine was a key aroma marker discriminating pork breeds.

1. Introduction

The roasted pork has long captivated consumers with its rich aroma. Over the past decade, the significant efforts have been directed toward deciphering the aroma formation during processing of pork. These studies have predominantly focused on understanding how exogenous factors, including temperature, time, heating method, and additive, modulate the aroma profiles in samples through lipid oxidation and Maillard reactions. In detail, an appropriate duration of hot air drying can significantly enhance the content of aroma compounds in non-smoked bacon, such as 2-heptanone and 1-octen-3-ol, which are primarily derived from the oxidation of free fatty acids and polar/neutral lipids (Wu et al., 2024). The substantial increase in the aroma compounds of pork belly is primarily attributed to the addition of spices and the oxidation of unsaturated fatty acids induced by free radical attacks during the heating process, among which 1-octen-3-ol, dimethyl disulfide, 2-ethyl-5-methylpyrazine, and 2-pentylfuran are the predominant odorants (Wang et al., 2023). The types of firewood (beech and olive) significantly affect the perception of a few key attributes containing roasty and grassy notes and the formation of aroma compounds in roasted pork (Piochi et al., 2024). The extracts from hawberry (Crataegus monogyna Jacq.) can effectively inhibit the lipid oxidation and aroma deterioration during the roasting process of pork (Akcan et al., 2017). Our previous studies have elucidated that all four roasting methods produce abundant aroma compounds in roasted pork, among which the air-fryer roast is an alternative roasting method to traditional burning charcoal owing to their similar heat and mass transfer (Liu et al., 2024). However, most previous studies have focused on a single pork genotype, overlooking the potential effect of genetic background and breed-specific precursor composition on the aroma formation. As a result, it remains unclear how different pig breeds contribute to the development of aroma compounds during roasting. Therefore, further study is needed to investigate the aroma fingerprints of roasted pork from various breeds and to clarify the role of intrinsic biological factors in shaping aroma profiles during thermal processing.

The emerging evidence has elucidated the substantial differences in aroma compounds of raw pork meat among different pig breeds. Specifically, significant differences in aroma compounds among Ningxiang pigs, Berkshire pigs, and their crossbred pigs are primarily attributed to variations in intramuscular fat content and the composition and levels of lipids in the raw pork meat (Wang et al., 2024). The oleic acid, α-linolenic acid, and docosahexaenoic acid are key contributors to the aroma formation in Chinese indigenous pigs, among which the hexanal and 1-octen-3-ol serve as potential aroma markers for discriminating the pork from Laiwu pig, Duroc × (Landrace × Yorkshire) pig, and Beijing black pigs (Wu et al., 2022). The variations in the levels of specific lipids and fatty acids, such as α-linolenic acid and PE O (18:2/18:2), will cause the differences in the concentrations of key odorants, as confirmed in different pork cuts (Duan et al., 2024). Additionally, the aroma fingerprints and key aroma compounds containing heptanal, octanal, and 2-pentylfuran of bacon from the eight regions exhibit distinct characteristics, primarily resulting from the synergistic effects of geographical location, processing techniques, and pork breeds (Liu et al., 2025). This phenomenon suggests that differences among pig breeds cause the variations in aroma precursors, which in turn result in breed-specific levels of heat-induced aroma formation. China is home to over 100 indigenous pig breeds. However, no studies have determined which pig breed is most suitable for roasting, nor have they developed methods to identify pork that is optimal for this purpose, thereby limiting the industrial advancement.

In addition to genetic and processing variables, the accuracy and sensitivity of analytical techniques used to characterize aroma compounds profoundly affect the reliability of conclusions drawn. While the gas chromatography-olfactometry-mass spectrometry (GC-O-MS) offers robust identification of aroma molecules, they often rely on single capillary columns and single ionization modes, which limit their capacity to detect trace-level odorants or compounds of different polarities (Pan et al., 2025). To address these limitations, advanced techniques such as gas chromatography-ion mobility spectrometry (GC-IMS) and comprehensive two-dimensional gas chromatography–mass spectrometry (GC × GC–MS) have emerged as powerful tools for the aroma analysis. Its applicability to meat product analysis has been demonstrated in the report from Yan et al. (2025), who employ GC-IMS and GC–MS to identify the aroma profiles of pre-cooked goose meat. The GC × GC–MS extends the dimensionality of separation by employing orthogonal column sets, revealing the subtle differences in key odorants among different bacon (Ruan et al., 2023). These hybrid approaches offer a multidimensional lens through which the complexity of aroma profile of meat products can be unraveled, facilitating the precise identification of key odorants.

This study aimed to (i) systematically compare the aroma fingerprints of roasted pork from different pig breeds using both electronic nose (E-nose) and GC-IMS, (ii) determine key aroma compounds and their breed-specific variations in samples using GC-O-MS and GC × GC–MS, and (iii) screen potential aroma markers discriminating roasted pork from different breeds via partial least squares discriminant analysis (PLS-DA). By integrating advanced instrumental techniques with multivariate statistical methods, this study provides both a scientific basis for selecting optimal pig breeds for roasting and a methodological reference for the raw material selection in meat product development.

2. Materials and methods

2.1. Materials

Fifteen 8-month-old pigs were selected, including three Nanyang black pigs (NBP), three Landrace pigs (LAP), three Junan indigenous pigs (JUP), three Wujin pigs (WUP), and three Min pigs (MIP). All pigs were slaughtered in accordance with the guidelines of the Animal Care and Use Committee of Ludong University (LDU-IRB202410009) (Supplementary material). Meanwhile, the study was carried out in accordance with Guidance on the operation of the Animals (Scientific Procedures) Act 1986 and associated guidelines, EU Directive 2010/63 for the protection of animals used for scientific purposes or the NIH (National Research Council) Guide for the Care and Use of Laboratory Animals (PDF) or those of an equivalent internationally recognized body. The experiment was conducted in accordance with the ethical guidelines. Briefly, the pigs underwent the slaughter by the captive bolt stunning with subsequent severing of the jugular and carotid vessels to induce the exsanguination, resulting in rapid cardiac failure and death. After the maturation at 4 °C, the tenderloin meat was then cut into blocks measuring 3 × 3 × 2 cm3, followed by the roast process at 230 °C for 20 min in a CKY-298 oven (German Pool Co., Ltd., Hong Kong, China). The sensory evaluation indicated that pork roasted under the condition exhibited the highest overall acceptability. After the roast, the internal temperature reached 72–76 °C, monitored using an LK1048U multi-channel temperature detector (Changzhou Blu-ray Electronics Co., Ltd., Jiangsu, China).

These chemical standards were obtained from Sigma-Aldrich (Shanghai, China), such as dimethyl disulfide (99 %), hexanal (98 %), 2-pentylfuran (98 %), octanal (99 %), dimethyl trisulfide (98 %), 2,3-dimethylpyrazine (95 %), 1-hexanol (98 %), 2-ethyl-6-methylpyrazine (98 %), 2-ethyl-5-methylpyrazine (98 %), (E)-2-heptenal (95 %), 2,3,5-trimethylpyrazine (99 %), 3-ethyl-2,5-dimethylpyrazine (98 %), 1-octen-3-ol (98 %), decanal (98 %), 3,5-diethyl-2-methylpyrazine (95 %), benzaldehyde (99 %), 1-octanol (99 %), and benzeneacetaldehyde (95 %). The n-alkanes (C7-C40, 97 %) were sourced from o2si Smart Solutions (Shanghai, China), while 2-methyl-3-heptanone (99 %) was obtained from Dr. Ehrenstorfer (Shanghai, China).

2.2. Sensory evaluation

Informed consent was obtained from all panelists prior to the sensory evaluation of roasted pork. The evaluation procedures were approved by the institutional review board of Ludong University (LDU-IRB202410003), with all protocols designed to uphold ethical standards and protect panelist privacy. Twelve trained sensory panelists were selected according to ISO 4121:2003 and GB/T 29604–2013 standards. Five key aroma descriptors containing roasty, fatty, meaty, sweet, and grassy were identified as the dominant attributes for roasted pork profiles. The panelists independently rated the perceived intensity of each aroma attribute using a 10-point scale, where 0 and 10 indicated no perception and extremely strong intensity, respectively (Liu et al., 2019).

2.3. E-nose analysis

The cNose system (Shanghai Baosheng Industrial Development Co., Ltd., Shanghai, China) was applied to investigate the aroma profiles of roasted pork from five breeds. This device integrates 18 specialized sensors (S1-S18) that are selectively reactive to key chemical groups such as alkanes, alcohol-ketone mixtures, sulfides, nitrogen-containing compounds. For each measurement, the volatiles from 4 g of roasted pork were delivered through the sensor array at a flow rate of 1 L/min, with a detection time of 60 s and an air purging duration of 120 s (Barbosa-Pereira et al., 2019).

2.4. GC-IMS analysis

The aroma fingerprints of roasted pork from five breeds were analyzed using GC-IMS (FlavourSpec®, Dortmund, Germany). A total of 4 g of roasted pork was incubated at 60  °C for 20 min under the constant agitation at 500 r/min to fully release volatile compounds. The chromatographic separation was achieved using an MXT-WAX capillary column (15 m × 0.53 mm × 1 μm). The programmed flow was initiated at 2 mL/min for 2 min, followed by a gradual increase to 100 mL/min over 18 min and maintenance for 30 min. The n-alkanones ranging from C4 to C9 were applied for the data calibration (Hua et al., 2025).

2.5. GC-O-MS analysis

The detailed analytical procedure containing the temperature program was consistent with our previous report (Liu, Liu, et al., 2023; Liu, Piao, et al., 2023). Briefly, the aroma compounds in roasted pork from five different breeds were analyzed using a TRACE™ 1310 GC–MS (Q Exactive GC, Thermo Scientific, Bremen, Germany) equipped with a OP275 Pro II olfactory port. The 3 g of minced pork samples and 1.5 μL of 2-methyl-3-heptanone were placed into a vial, which was then subjected to extraction using a 75 μm CAR/PDMS SPME fiber. The pre-equilibration was performed at 55 °C for 10 min, followed by adsorption at the same temperature for 45 min. The separation of aroma compounds was achieved on a DB-Wax capillary column (30 m × 320 μm × 0.25 μm) with the helium (purity ≥99.99 %) as the carrier gas at a constant flow rate of 1.20 mL/min. The mass spectra were acquired at 70 eV over 40–500 m/z with a resolution of 60,000 Full Width at Half Maximum (FWHM). Aroma compounds were identified based on mass spectral library matching (MS), linear retention index (LRI) calculation, olfactory detection (O), and comparison with authentic standards (S) (Liu et al., 2019).

2.6. GC × GC–MS analysis

The aroma analysis was conducted on a Shimadzu GC × GC–MS system (QP2020NX) equipped with a thermal modulator operating at a modulation period of 6 s. The aroma extraction was performed by employing a 75 μm SPME fiber. A non-polar SH-I-5Sil MS (30 m × 0.25 mm × 0.25 μm) and a mid-polar SH-17 column (1.2 m × 0.18 mm × 0.18 μm) columns were applied to separate the aroma compounds. The oven temperature program began at 40 °C with a 3-min hold, followed by an increase at 3 °C/min to 230 °C and a 5-min isothermal phase (Leni et al., 2024). The electron impact ionization occurred at 70 eV, with a scan range of 40–350 m/z and an ion source temperature setting of 230 °C. The relative odor activity values (ROAVs) were applied to evaluate their importance on the aroma profile, as previously described (Schieberle, 1995).

2.7. Statistical analysis

Differences (p < 0.05) among samples were assessed by one-way analysis of ANOVA in SPSS 19.0 software. The results were presented as mean ± standard deviation. The variable importance in projection (VIP) value greater than 1 and a significance level of p < 0.05 were employed to screen aroma markers. The data visualization was performed using Origin 2022 and SIMCA 14.1.

3. Results and discussion

3.1. Plotting of aroma fingerprints of roasted pork from different breeds using E-nose and GC-IMS

As illustrated in Fig. 1, the roasted pork from different breeds exhibited a complex aroma profile characterized by dominant roasty notes, accompanied by meaty, fatty, sweet, and grassy notes. The roasted pork from MIP and NBP displayed significantly higher overall sensory intensities than that from JUP, WUP, and LAP. These sensory outcomes suggested that the roasted pork from MIP and NBP might possess elevated levels of aroma compounds. This phenomenon aligns with our previous findings, where roasty, meaty, fatty, sweet, and grassy were identified as key aroma attributes of roasted pork, with roasty, meaty, and fatty notes being particularly prominent (Li et al., 2024). To further elucidate these differences, an E-nose was employed to capture the overall aroma profiles (Fig. 2). The sensor array responses indicated that all roasted pork contained considerable amounts of carbonyls and alcohols, as proven by the pronounced signals of S6 and S9 sensors. However, the roasted pork from MIP stood out by eliciting high responses in 14 out of 18 sensors, highlighting its greater chemical complexity. Notably, the sensors sensitive to carbonyls (S6), nitrogen-containing compounds (S5), and sulfur-containing compounds (S16) showed particularly strong responses for the roasted pork from MIP. In contrast, the roasted pork from LAP and WUP exhibited the weak overall sensor signals, implying a lower concentration of aroma compounds. This is consistent with the previous result, where the use of E-nose effectively distinguishes the pork meatballs with different aroma intensities subjected to the ultrasonic treatment ranging from 0 to 750 W (Zhao et al., 2025).

Fig. 1.

Fig. 1

Open in a new tab

Sensory evaluation of roasted pork from different breeds.

NBP, LAP, JUP, WUP, and MIP represent the roasted pork from the corresponding pig breeds.

Fig. 2.

Fig. 2

Open in a new tab

Aroma type analysis in roasted pork from different breeds using E-nose.

Probes S1-S18 were sensitive to the propane, carbon-containing compounds, hydrogen, sulfides, nitrogen-containing compounds, aldehydes and ketones, short-chain alkanes, liquefied gas, alkyl with alcohols and ketones, hydrogen gas, alkanes, methane, short-chain alkanes, methane, carbon-containing compounds with alcohols and aldehydes, hydrogen sulfide, ammonia, toluene with acetone and ethanol, respectively. NBP, LAP, JUP, WUP, and MIP represent the roasted pork from the corresponding pig breeds.

The differences of aroma compounds of roasted pork were further characterized using GC-IMS. As depicted in Fig. 3a, the density and intensity of red spots, which corresponded to the concentrations of specific compounds, were highest in the roasted pork from MIP and lowest in LAP meat. The three-dimensional GC-IMS plots provided a more detailed information, revealing that the roasted pork from MIP generated a greater number of peaks with higher intensities, followed by that from NBP, WUP, and JUP, while LAP meat presented the lowest aroma concentrations (Fig. 3b). The Fig. 3c offered a comprehensive aroma fingerprint of detected compounds, where the transition from blue to yellow to red signified increasing concentrations of compounds. In detail, carbonyls and alcohols were the predominant classes across all pork samples, with 2-butanol, 1-propanol, 2-propanone, and 2-pentanone being common aroma compounds among the five breeds. This may be attributed to the high content of carbonyls and alcohols in the raw pork materials, as well as their precursors such as oleic acid and linoleic acid (Wu et al., 2022). The roasted pork from MIP was particularly enriched in butanal, pentanal, heptanal, (E)-2-heptenal, 1-octanol, and 2-heptanone, all of which were known contributors to desirable fatty and grassy aromas. The roasted pork from WUP and JUP contained higher levels of compounds containing 3-pentanone and 1,2-propanediol. Conversely, the LAP meat was characterized by generally low concentrations of most compounds, including 2-methyl-1-propanol, underscoring its weak aroma profile. The GC-IMS successfully identifies the aroma fingerprints and differences of dry-cured pork with 0 %–7 % salt content, among which the carbonyls and alcohols are found to be the predominant aroma compounds in processed pork products (Tian et al., 2020). Overall, the results of both the E-nose and GC-IMS were generally consistent with the sensory evaluation, indicating that the roasted pork from MIP possessed a richer aroma fingerprint and a higher concentration of aroma compounds after roasting.

Fig. 3.

Fig. 3

Open in a new tab

Aroma fingerprint analysis in roasted pork from different breeds using GC-IMS.

(a) 2D topographic plots. (b) 3D topographic plot. (c) Heatmap visualization of aroma compounds in roasted pork from different breeds. NBP, LAP, JUP, WUP, and MIP represent the roasted pork from the corresponding pig breeds.

3.2. Determination of aroma profile of roasted pork from different breeds using GC-O-MS and GC × GC–MS

As presented in Table 1, 30 aroma compounds were detected in roasted pork from different breeds, which predominantly belonged to the categories of nitrogen-containing compounds, aldehydes, alcohols, sulfur-containing compounds, ketones, and phenols. Notably, pyrazines and aldehydes accounted for more than 50 % of the total aroma profile. This aligned with results from electronic nose sensors S5 and S6, which were sensitive to nitrogen-containing compounds and carbonyls, showing higher response values. These findings also corroborate the prior report, highlighting the crucial role of Maillard reactions and lipid oxidation in shaping the characteristic aroma profile of pork (Totlani & Peterson, 2005; Zhou et al., 2025). The number of aroma compounds varied across the breeds, among which 15, 16, 17, 10, and 23 compound were identified in the roasted pork from NBP, LAP, JUP, WUP, and MIP, respectively. Seven compounds, including dimethyl disulfide, hexanal, octanal, dimethyl trisulfide, 2-ethyl-1-hexanol, benzaldehyde, and butyrolactone, were detected in all five pig breeds, reinforcing the shared sensory attributes of roasted pork. The most abundant aroma compounds in roasted pork were 3-ethyl-2,5-dimethylpyrazine (4122.35–24,637.13 ng/g), 2,3,5-trimethylpyrazine (0–17,216.15 ng/g), and 1-octanol (0–16,454.49 ng/g). Other significant compounds included benzaldehyde (11,528.57–15,007.76 ng/g), 2,3-dimethylpyrazine (0–10,365.56 ng/g), and (E)-3-hexen-1-ol (0–10,139.98 ng/g). The roasting time at 250 °C significantly increases the concentrations of aroma compounds in roasted pork, especially with a high concentration of pyrazines detected (Ji et al., 2024). Particularly, the MIP displayed the highest diversity, which corresponded with the elevated response values of its 18-sensor electronic nose array. Compared to the roasted pork from NBP, LAP, JUP, and WUP, MIP meat exhibited the highest concentrations of 20 out of 30 aroma compounds, such as hexanal, dimethyl trisulfide, 3,5-diethyl-2-methylpyrazine, 3-ethylpyridine, and 1-octen-3-ol, suggesting substantial differences in the free fatty acid, amino acid, and reducing sugar profiles among the pig breeds (Adams et al., 2011).

Table 1.

Concentration of aroma compounds in roasted pork from different breeds using GC-O-MS.

Compounds(ng/g) Retention time LRI
 Identification NBP LAP JUP WUP MIP
calculation theory
dimethyl disulfide 6.23 1043 1050 MS, LRI, O, S 2493.62 ± 134.71b 2215.67 ± 245.71b 2178.17 ± 133.82b 1812.66 ± 263.94c 3273.52 ± 68.06a
hexanal 6.54 1055 1051 MS, LRI, O, S 2730.99 ± 216.01c 2804.64 ± 571.31c 5194.83 ± 509.28b 4594.65 ± 152.12b 9111.72 ± 470.47a
2-pentylfuran 11.02 1194 1193 MS, LRI, O, S – 292.45 ± 8.25a 112.62 ± 11.81b – 63.65 ± 18.89c
octanal 13.27 1250 1248 MS, LRI, O, S 21.82 ± 0.87c 50.07 ± 6.09b 24.42 ± 1.52c 29.24 ± 1.07c 82.63 ± 10.49a
dimethyl trisulfide 15.94 1319 1329 MS, LRI, O, S 36.20 ± 3.31e 150.11 ± 24.09c 82.23 ± 6.20d 225.31 ± 7.78b 267.38 ± 26.03a
2,3-dimethylpyrazine 17.77 1361 1363 MS, LRI, O, S – – 6150.24 ± 441.79b – 10,365.56 ± 1074.19a
1-hexanol 17.86 1363 1362 MS, LRI, O, S – 592.36 ± 114.76b – – 8802.63 ± 829.40a
2-ethyl-6-methylpyrazine 18.35 1376 1375 MS, LRI, O, S – – 262.88 ± 16.78b – 2437.31 ± 128.85a
2-ethyl-5-methylpyrazine 18.40 1377 1376 MS, LRI, O, S 1341.73 ± 325.61b – 1521.45 ± 96.97b – 3254.70 ± 267.25a
(E)-2-heptenal 18.43 1377 1366 MS, LRI, O, S 56.23 ± 6.02 – – – –
3-ethylpyridine 18.60 1382 1384 MS, LRI 307.28 ± 5.39b 284.20 ± 15.39b – – 1827.87 ± 133.18a
(E)-3-hexen-1-ol 19.80 1411 1410 MS, LRI – 192.78 ± 10.76b – – 10,139.98 ± 955.95a
2,3,5-trimethylpyrazine 19.91 1414 1413 MS, LRI, O, S 5840.18 ± 1181.51c 141.39 ± 10.12d 7935.26 ± 1250.85b – 17,216.15 ± 983.92a
5-ethyl-2,4-dimethylthiazole 20.43 1427 1428 MS, LRI – – 111.96 ± 10.01 – –
3-ethyl-2,5-dimethylpyrazine 20.74 1434 1433 MS, LRI, O, S 4122.35 ± 93.64c 5091.50 ± 267.98c 16,486.41 ± 2265.90b – 24,637.13 ± 1562.84a
1-octen-3-ol 20.94 1440 1442 MS, LRI, O, S – – – – 4013.59 ± 129.88
decanal 21.33 1449 1448 MS, LRI, O, S – 186.13 ± 11.74b – – 1555.54 ± 141.67a
4-methyl-1-hexanol 21.39 1451 1445 MS, LRI 103.53 ± 5.97 – – – –
2,6-diethylpyrazine 21.46 1452 1456 MS, LRI – 1387.44 ± 106.39 – – 1513.62 ± 153.94
3,5-diethyl-2-methylpyrazine 21.94 1464 1469 MS, LRI, O, S 189.28 ± 9.18d – 399.83 ± 18.41b 333.26 ± 14.85c 705.42 ± 38.11a
2-ethyl-1-hexanol 22.54 1479 1470 MS, LRI 501.98 ± 21.91b 1632.96 ± 463.25a 1733.13 ± 243.20a 628.73 ± 31.14b 587.48 ± 105.63b
tetramethylpyrazine 22.58 1480 1483 MS, LRI – – 400.99 ± 15.20 – –
benzaldehyde 22.78 1485 1485 MS, LRI, O, S 12,858.90 ± 977.43bc 15,007.76 ± 155.49a 14,590.94 ± 182.77ab 14,033.14 ± 1756.62ab 11,528.57 ± 688.98c
1-octanol 25.17 1542 1540 MS, LRI, O, S – 722.54 ± 38.46b – – 16,454.49 ± 1123.25a
benzeneacetaldehyde 27.53 1598 1592 MS, LRI, O, S – – 953.30 ± 94.83b – 1921.54 ± 129.11a
butyrolactone 27.67 1602 1602 MS, LRI 663.65 ± 30.70c 394.19 ± 16.52d 496.35 ± 28.42cd 1252.56 ± 116.44b 3664.47 ± 245.61a
acetophenone 27.88 1608 1606 MS, LRI – – – – 144.94 ± 6.32
2-thiophenecarboxaldehyde 29.65 1659 1659 MS, LRI – – – 120.35 ± 25.87 –
phenol 39.65 1981 1978 MS, LRI 192.23 ± 4.22 – – – –
p-cresol 41.13 2061 2060 MS, LRI – – – 239.56 ± 39.7 –
Open in a new tab

The data with different letters (a, b, c, d, and e) in the same row indicate the significant differences at p < 0.05. Note: “-” indicates not detected. NBP, LAP, JUP, WUP, and MIP represent the roasted pork from the corresponding pig breeds.

Unfortunately, the GC-O-MS data alone were insufficient to fully explain sensory differences, particularly in the fatty aromas. Seventy-eight aroma compounds were identified across the roasted pork samples, including 20 nitrogen-containing compounds, 19 ketones, 15 aldehydes, 6 furans, 6 acids, 5 esters, 4 alcohols, and 3 sulfur-containing compounds (Table 2). The predominance of pyrazines, which were key contributors to the roasty aroma, was evident across all pig breeds. The dimethyl disulfide (1686.17–11,243.03 ng/g), 2-methylpyrazine (2297.66–11,135.25 ng/g), 2,5-dimethylpyrazine (296.91–10,224.59 ng/g), and 2-ethyl-3-methylpyrazine (0–8422.39 ng/g) were identified at high concentrations. Other compounds, such as heptanal (3146.80–6873.03 ng/g), trimethylpyrazine (0–6795.71 ng/g), and 3-ethyl-2,5-dimethylpyrazine (1299.54–5633.38 ng/g), also significantly contributed to the aroma profile. The dominant presence of 3-ethyl-2,5-dimethylpyrazine, identified by both GC-O-MS and GC × GC–MS, underlined its importance in the roasted pork aroma. A significant amount of unsaturated aldehydes contributing to the fatty aroma were detected in roasted pork, including (E, E)-2,4-decadienal and (E)-2-octenal. Particularly, the roasted pork from MIP contained the highest concentration of 73 out of the 78 identified compounds, whereas NBP meat had the high levels of 22 specific compounds. The results clearly clarified that the roasted pork from MIP exhibited the highest types and the highest concentrations of aroma compounds among the five pig breeds. This phenomenon may be due to the abundant phospholipids and neutral lipids present in MIP, which play a pivotal role in promoting the formation and retention of key aroma compounds (Liu et al., 2024). This also confirmed the correlation between the subjective aroma intensity observed in sensory evaluation and the aroma fingerprints reflected by the E-nose and GC-IMS (Sun et al., 2023). The combination of GC-IMS, GC-O-MS, and GC × GC–MS proved to be an effective approach for capturing the comprehensive aromatic profile of samples (Li et al., 2021; Wang et al., 2019).

Table 2.

Concentration of aroma compounds in roasted pork from different breeds using GC × GC–MS.

Compounds(ng/g) Retention time
 LRI
 NBP LAP JUP WUP MIP
first-dimension time second-dimension time calculation theory
dimethyl disulfide 4.96 1.55 731 731 3867.98 ± 261.83c 1686.17 ± 72.92d 2327.10 ± 71.50d 5051.27 ± 550.21b 11,243.03 ± 964.92a
2-hexanone 4.96 1.17 731 728 755.06 ± 50.79b 371.69 ± 10.67d 605.35 ± 10.13c 833.41 ± 61.10b 2137.62 ± 141.37a
pyridine 5.06 1.95 735 735 6095.54 ± 212.97a 4483.67 ± 225.45b 2189.08 ± 60.66d 3751.99 ± 126.43c 4653.37 ± 215.12b
cyclopentanone 6.26 2.53 781 780 648.23 ± 34.39cd 463.81 ± 14.13d 812.64 ± 76.08c 1615.52 ± 74.51b 2339.15 ± 260.69a
dihydro-2-methyl-3(2H)-furanone 6.86 2.67 803 804 1216.63 ± 89.17c 753.45 ± 51.05d 1535.10 ± 103.91b 918.63 ± 105.02d 1868.09 ± 119.59a
hexanal 6.96 2.16 805 802 485.67 ± 42.97c 236.07 ± 22.61d 50.80 ± 1.02e 621.39 ± 27.29b 852.12 ± 76.96a
2-methylpyridine 7.26 2.42 813 814 – – – – 484.05 ± 45.34
2-methylpyrazine 7.46 2.65 818 816 4927.53 ± 302.66c 2297.66 ± 179.68d 6153.91 ± 155.30b 6526.19 ± 171.03b 11,135.25 ± 368.60a
furfural 7.76 3.27 825 825 39.45 ± 1.51c 56.25 ± 1.66c 15.84 ± 1.30d 74.43 ± 13.43b 143.07 ± 17.43a
4-methyl-2-hexanone 8.36 1.83 840 846 124.04 ± 4.01b 143.24 ± 5.64b 90.97 ± 12.81c 153.48 ± 24.21b 759.21 ± 23.75a
2-furanmethanol 8.56 2.88 845 844 142.38 ± 8.85c 86.51 ± 15.36d 191.91 ± 26.96b 230.44 ± 24.89b 281.40 ± 39.31a
5-methyl-2-hexanone 8.86 1.93 853 857 1161.63 ± 42.68c 517.47 ± 23.81d 1506.72 ± 107.52b 706.43 ± 35.01d 3530.73 ± 219.13a
2-methyl-cyclopentanone 8.46 2.67 842 842 45.80 ± 1.53c 37.61 ± 1.58c 15.27 ± 1.48d 58.37 ± 0.98b 86.57 ± 10.00a
3-methylbutanoic acid 8.46 1.46 842 839 – – – – 618.32 ± 17.39
(E)-2-hexenal 8.66 2.61 847 845 45.29 ± 1.30b 8.75 ± 1.26d 6.41 ± 0.16d 37.29 ± 2.94c 66.98 ± 7.89a
1-(acetyloxy)-2-propanone 9.86 3.78 878 862 870.05 ± 167.87c 359.16 ± 15.87e 605.95 ± 15.73d 1932.04 ± 122.47b 2454.90 ± 196.29a
2-heptanone 10.26 2.09 888 889 90.99 ± 3.66c – – 1913.14 ± 141.15b 3175.42 ± 189.37a
pentanoic acid 10.16 1.68 885 883 – – – 302.03 ± 52.37 330.63 ± 40.43
heptanal 10.76 2.12 900 900 3197.80 ± 122.55c 3146.80 ± 329.71c 3336.61 ± 98.44c 5192.60 ± 228.46b 6873.03 ± 233.10a
methional 10.86 4.08 902 902 350.45 ± 26.32a 190.45 ± 22.28b 207.01 ± 17.25b 376.66 ± 20.82a 170.61 ± 11.27b
butyrolactone 11.06 0.45 906 908 940.34 ± 88.02d 917.34 ± 95.32d 1414.41 ± 95.95c 1700.60 ± 95.05b 3078.37 ± 195.11a
1-(2-furanyl)-ethanone 11.26 3.72 910 910 398.74 ± 28.29c – – 533.17 ± 41.48b 1195.98 ± 103.11a
2,5-dimethylpyrazine 11.16 2.73 908 909 8893.85 ± 711.33b 7736.46 ± 550.16c 296.91 ± 14.71d 10,058.03 ± 693.70a 10,224.59 ± 279.20a
2-methyl-3-(methylthio) furan 12.86 2.82 944 944 – – – 68.02 ± 6.00b 236.47 ± 6.81a
benzaldehyde 13.46 4.02 956 954 3777.34 ± 450.83b 551.46 ± 15.72c 322.11 ± 48.36c 3741.10 ± 154.65b 4857.50 ± 446.46a
3-ethylpyridine 13.66 3.21 960 962 2303.97 ± 171.50b 52.92 ± 1.66c 32.18 ± 2.00c 19.29 ± 1.67c 5147.40 ± 577.24a
dimethyl trisulfide 13.76 3.70 963 963 1749.04 ± 84.07c 977.18 ± 38.44d 595.18 ± 19.67e 2653.11 ± 137.47b 2943.26 ± 100.48a
4-octanone 14.06 2.16 969 970 – – – 536.45 ± 32.36b 908.90 ± 51.99a
3-methylpentanoic acid 14.56 1.91 979 971 – – – – 738.96 ± 23.34
1-octen-3-ol 14.56 1.95 979 979 502.86 ± 39.18c – – 1772.11 ± 81.93b 2251.71 ± 65.24a
6-methyl-5-hepten-2-one 14.76 2.67 983 983 122.17 ± 13.04d 300.27 ± 39.12b 238.24 ± 37.11c 198.62 ± 20.44c 372.33 ± 32.03a
2-methyl-3-octanone 14.76 2.31 983 984 1317.30 ± 274.21b – – 1450.55 ± 252.70b 2364.19 ± 226.17a
hexanoic acid 14.96 1.99 987 988 – – – – 732.01 ± 37.48
2-pentylfuran 14.96 1.97 988 988 396.92 ± 44.90c 302.81 ± 31.26d 90.21 ± 14.71e 468.62 ± 33.98b 732.01 ± 37.48a
2-ethyl-3-methylpyrazine 15.36 3.29 996 999 – – – – 8422.39 ± 481.73
trimethylpyrazine 15.46 3.28 998 999 5762.50 ± 448.55b – 151.31 ± 22.97c 6239.45 ± 335.29b 6795.71 ± 296.92a
octanal 15.66 2.30 1002 1002 1608.42 ± 57.98c 811.51 ± 74.86e 1247.29 ± 74.41d 2216.65 ± 168.96b 2772.23 ± 215.41a
2-ethenyl-6-methylpyrazine 16.26 3.66 1014 1016 – – – 47.84 ± 7.05b 138.35 ± 6.86a
2-ethyl-1-hexanol 17.06 2.02 1030 1030 1910.60 ± 160.15b 1337.98 ± 277.90c 1440.3 ± 368.53c 1971.1 ± 156.33ab 2342.09 ± 71.69a
2,3-dimethyl-2-cyclopenten-1-one 17.06 4.30 1030 1034 – – – 125.13 ± 5.55a 81.69 ± 15.51b
2,4-dimethyl-cyclohexanol 17.26 2.52 1034 1032 106.63 ± 7.22b – 62.40 ± 4.93c 100.75 ± 14.92b 129.42 ± 21.86a
benzeneacetaldehyde 17.56 4.50 1040 1039 373.41 ± 48.02bc 338.17 ± 23.40c 383.75 ± 21.06bc 443.25 ± 19.49b 587.90 ± 83.50a
furaneol 18.26 3.77 1054 1051 – – – – 92.39 ± 9.22
(E)-2-octenal 18.46 1.36 1057 1062 177.86 ± 13.89c 68.36 ± 1.88d 39.00 ± 2.43d 394.91 ± 17.69b 676.22 ± 28.17a
1-(1H-pyrrol-2-yl)ethanone 18.46 4.82 1058 1064 – – – – 86.92 ± 9.95
acetophenone 18.56 4.44 1060 1060 – – – – 74.59 ± 13.25
1-octanol 19.16 2.18 1072 1073 98.51 ± 15.38c 60.96 ± 1.83d 44.85 ± 1.42d 188.88 ± 16.35b 259.31 ± 5.80a
3-ethyl-2,5-dimethylpyrazine 19.26 3.27 1072 1072 2596.24 ± 116.41b 1299.54 ± 55.40d 2155.72 ± 123.24c 2805.74 ± 145.10b 5633.38 ± 131.57a
2,3-dimethyl-5-ethylpyrazine 19.56 3.27 1080 1084 – – – – 1092.60 ± 52.54
2-nonanone 20.06 2.39 1090 1090 71.31 ± 4.58d 47.46 ± 4.07e 98.76 ± 7.44c 173.28 ± 12.44b 193.85 ± 16.94a
nonanal 20.66 2.37 1102 1102 1742.63 ± 93.63d 1339.96 ± 83.64e 2739.53 ± 84.08c 3195.04 ± 303.08b 4688.93 ± 304.56a
2-acetyl-3-methylpyrazine 21.26 4.01 1114 1112 – – – – 63.03 ± 3.67
2-isobutyl-3-methylpyrazine 22.16 3.04 1133 1134 13.20 ± 1.84b 29.44 ± 5.26a – – 33.23 ± 2.05a
5H-5-methyl-6,7-dihydrocyclopentapyrazine 22.26 4.36 1135 1139 16.30 ± 7.15b 11.34 ± 0.91b 10.06 ± 2.46b 25.46 ± 6.07a 29.05 ± 3.10a
(E)-2-nonenal 22.76 1.32 1146 1145 – – – – 113.03 ± 9.44
dihydro-5-propyl-2(3H)-furanone 22.76 5.23 1145 1155 – – – – 17.45 ± 2.53
3,5-diethyl-2-methylpyrazine 23.06 3.13 1151 1152 79.42 ± 2.37d 141.38 ± 8.19b 64.27 ± 5.78e 119.75 ± 7.03c 170.77 ± 11.76a
2,5-dimethyl-3-propylpyrazine 23.26 3.13 1155 1162 67.61 ± 5.55c 116.55 ± 11.45b 74.35 ± 4.96c 124.87 ± 11.14b 187.33 ± 24.66a
2,3-diethyl-5-methylpyrazine 23.56 3.17 1161 1162 9.08 ± 1.28b 7.11 ± 0.34b 10.95 ± 1.51b 8.13 ± 0.82b 197.41 ± 9.55a
octanoic acid 23.96 2.23 1169 1165 83.73 ± 7.95b 112.27 ± 8.80a 83.54 ± 4.61b – 75.18 ± 14.87b
2-decanone 24.96 2.38 1190 1191 24.86 ± 1.18c 23.06 ± 4.80c 60.72 ± 3.89b 95.05 ± 5.36a 88.80 ± 5.40a
2,5-dimethyl-3-(2-methylpropyl)pyrazine 25.26 2.92 1196 1193 19.01 ± 1.55c 23.52 ± 2.90c 17.13 ± 0.45c 50.90 ± 3.45b 81.56 ± 14.47a
decanal 25.66 2.34 1204 1204 85.34 ± 3.62c 64.54 ± 7.85d 89.12 ± 10.15c 126.00 ± 8.28b 186.25 ± 13.03a
6,7-dihydro-2,5-dimethyl-5H-cyclopentapyrazine 26.26 4.17 1217 1220 13.32 ± 1.44 – – 15.86 ± 1.92 18.71 ± 5.01
2-isoamyl-6-methylpyrazine 27.66 3.10 1248 1248 10.17 ± 3.13b – – 14.05 ± 4.09ab 15.40 ± 2.10a
hexanoic acid pentyl ester 29.46 2.19 1287 1287 100.64 ± 6.52c 114.16 ± 15.01c 74.30 ± 10.06d 141.76 ± 11.00b 167.56 ± 4.25a
2-undecanone 29.66 2.37 1291 1291 8.95 ± 1.61c 9.96 ± 1.64c 13.41 ± 4.43bc 17.33 ± 2.26ab 18.37 ± 1.83a
undecanal 30.36 2.33 1307 1307 – – 10.53 ± 2.14b 15.71 ± 0.92a 15.77 ± 0.84a
2,5-dimethyl-3-(3-methylbutyl)pyrazine 30.46 2.99 1309 1308 22.69 ± 0.52cd 25.76 ± 2.70c 18.00 ± 3.59d 36.27 ± 4.56b 52.04 ± 6.44a
(E, E)-2,4-decadienal 30.76 1.46 1316 1314 – – – – 78.3 ± 10.62
n-butyric acid 2-ethylhexyl ester 30.96 2.07 1320 1321 24.02 ± 2.57d 26.77 ± 4.55cd 32.58 ± 4.26bc 36.65 ± 3.85b 50.22 ± 5.91a
2-butyl-2-octenal 33.06 2.40 1368 1367 – – – – 28.23 ± 6.30
hexanoic acid hexyl ester 33.76 2.19 1384 1383 34.88 ± 7.60c 61.85 ± 12.10b 23.75 ± 2.77c 98.72 ± 14.22a 108.94 ± 13.25a
dodecanal 34.76 2.33 1407 1407 33.84 ± 5.07c 18.49 ± 2.91d 51.52 ± 4.07a 43.09 ± 3.51b 58.53 ± 6.20a
n-heptyl hexanoate 37.76 2.19 1480 1482 – – – – 20.64 ± 1.86
hexanoic acid octyl ester 41.76 2.18 1580 1575 7.10 ± 0.50b 12.21 ± 1.43a 5.15 ± 0.19b 6.00 ± 0.48b 14.04 ± 2.72a
tetradecanal 42.96 2.24 1611 1611 – – – 9.59 ± 0.97b 13.89 ± 2.51a
n-hexadecanoic acid 55.16 2.47 1959 1958 76.72 ± 8.17bc 66.44 ± 1.77c 94.01 ± 24.24b 91.28 ± 11.34b 131.41 ± 6.68a
Open in a new tab

The data with different letters (a, b, c, d, and e) in the same row indicate the significant differences at p < 0.05. Note: “-” indicates not detected. NBP, LAP, JUP, WUP, and MIP represent the roasted pork from the corresponding pig breeds.

3.3. Characterization of key aroma compounds contributing to aroma differences among roasted pork from different breeds

Although the types of aroma compounds that played a crucial role in the aroma of roasted pork had been identified, the key compounds responsible for the distinct aroma characteristics of roasted pork remain unknown. As presented in Fig. 4, a total of 31 aroma compounds with ROAVs >1 were identified across the different pork breeds using GC × GC–MS, including 11 nitrogen-containing compounds, 9 aldehydes, 4 ketones, 3 sulfur-containing compounds, 2 alcohols, 1 acid, and 1 furan. Among these, the dimethyl trisulfide exhibited the highest ROAVs (0–294,326.34), followed by 2-ethyl-3-methylpyrazine (0–21,055.97), 3-ethyl-2,5-dimethylpyrazine (1299.54–5633.38), and 2,3-dimethyl-5-ethylpyrazine (0–5463.00). Other compounds, such as nonanal (1339.96–4688.93), heptanal (1048.93–2291.01), 1-octen-3-ol (0–2251.71), and 3,5-diethyl-2-methylpyrazine (642.72–1707.72), also exhibited high ROAVs, indicating their significant contribution to the aroma profile of roasted pork. This is mainly due to the intense lipid oxidation and Maillard reactions that occur in the meat during roasting, resulting in the formation of large amounts of sulfur-containing, nitrogen-containing, and aldehyde compounds, such as dimethyl trisulfide, 2,3-diethyl-5-methylpyrazine, and hexanal (Gąsior et al., 2021). In total, 23, 18, 16, 22, and 31 key aroma compounds were detected in the roasted pork from NBP, LAP, JUP, WUP, and MIP, respectively, with 13 shared compounds across all, including 3-ethyl-2,5-dimethylpyrazine, hexanal, nonanal, and 3,5-diethyl-2-methylpyrazine. These compounds were largely responsible for the intense roasty, meaty, and grassy aromas. This is consistent with our previous report, in which 3-ethyl-2,5-dimethylpyrazine, nonanal, and hexanal with ROAVs >1 are detected in roasted pork, beef, lamb, revealing that they are common key aroma compounds in roasted meats (Shi et al., 2024).

Fig. 4.

Fig. 4

Open in a new tab

ROAVs analysis of aroma compounds in roasted pork from different breeds using GC × GC–MS.

NBP, LAP, JUP, WUP, and MIP represent the roasted pork from the corresponding pig breeds.

Notably, the total ROAVs of aroma compounds in the roasted pork from MIP (341,974.39) were the highest among the five pig breeds, followed by that of WUP (278,974.71) and NBP (184,159.24), while the roasted pork from JUP (67,683.07) and LAP (104,198.59) exhibited the lowest cumulative ROAVs, suggesting that the MIP meat had the most pronounced overall sensory intensity. In terms of roasty aroma, the nitrogen-containing compounds in the roasted pork from MIP contributed an ROAV sum of 34,290.17, followed by WUP (4154.16) and NBP (3514.82), while JUP (2915.44) and LAP (2774.05) had the lowest values. Among the key contributors to the roasty aroma, 2-ethyl-3-methylpyrazine (21,055.97) and 2,3-dimethyl-5-ethylpyrazine (5463.00) were only detected in MIP samples, while 3-ethyl-2,5-dimethylpyrazine (5633.38) and 3,5-diethyl-2-methylpyrazine (1707.72) showed the highest ROAVs in MIP samples compared to the other pig breeds. The LAP and JUP samples exhibited relatively low ROAVs for these compounds. This is consistent with our previous report, where the differences in roasty aroma in roasted meat were primarily attributed to varying levels of pyrazines, such as 3-ethyl-2,5-dimethylpyrazinec and 2,3-dimethyl-5-ethylpyrazine (Liu et al., 2024; Liu, Liu, et al., 2023; Liu, Piao, et al., 2023; Nie et al., 2024). Similarly, the roasted pork from MIP also exhibited the highest ROAVs for unsaturated aldehydes contributing to fatty aroma (1796.06), followed by that from WUP (131.64) and NBP (59.29), with LAP (22.79) and JUP (13.00) samples showing the lowest values. Compared with hams produced from hybrid pigs, the ham made from Dahe black pigs exhibits the highest aroma intensity and the highest contents of aldehydes and alcohols, which may be attributed to the higher levels of polyunsaturated fatty acids in Dahe black pigs, including linoleic acid and arachidonic acid (Wei et al., 2023). This has also been confirmed that the low salt mainly promotes the formation of aroma compounds in dry-cured ham by affecting the linoleic acid metabolism and fatty acid degradation processes, especially the lipid-derived carbonyl compounds (Liu, Liu, et al., 2023; Liu, Piao, et al., 2023). These results suggested that the roasted pork from MIP stands out in terms of aroma development due to the presence of high-ROAV aroma compounds. Although minor differences existed between subjective sensory evaluations and objective aroma compound analyses, the overall trends were consistent, with the data mutually corroborating each other. The addition of rosemary leaves increased the content of terpenic volatiles in the samples, which enhanced the herbal aroma, whereas the control samples exhibited a greasy aroma due to high levels of aldehydes (Heck et al., 2019).

3.4. Screen of aroma markers responsible for breed-specific differences in roasted pork using PLS-DA

As illustrated in Fig. 5, the roasted pork from different breeds were obviously separated without any overlap between groups, indicating clear discrimination among the breeds. The model parameters (R2X = 0.97, R2Y = 1, Q2 = 0.99) demonstrated excellent stability and predictive ability of the PLS-DA model. In detail, the roasted pork from NBP, JUP, and LAP were positioned on the positive side of the t1 axis, separating them from WUP and MIP samples. Notably, the roasted pork from MIP exhibited a negative value along the t2 axis, showing a marked discrimination from WUP samples. These results clearly indicated that both the overall aroma profiles and aroma intensities of roasted pork were different among breeds. This observation is consistent with the previous report, which demonstrates that genetic background significantly affects the aroma characteristics of cooked pork products (Han et al., 2020). Meanwhile, the findings confirm that subtle differences in aroma profiles in samples can be effectively discriminated using PLS-DA analysis. To further identify which specific aroma compounds contributed to these differences, the relationships between the aroma compounds and pork samples were analyzed. As illustrated in Fig. 5b, most aroma compounds clustered closer to MIP and NBP samples. Particularly, these compounds, including 2,3-dimethyl-5-ethylpyrazine, 2-ethyl-3-methylpyrazine, 2-acetyl-3-methylpyrazine, and 2,3-diethyl-5-methylpyrazine, were closely associated with MIP samples, while 2,5-dimethylpyrazine, pyridine, and dodecanal were mainly associated with NBP samples. In contrast, only octanoic acid appeared to be more closely related to the roasted pork from JUP and LAP.

Fig. 5.

Fig. 5

Fig. 5

Open in a new tab

PLS-DA of aroma compounds in roasted pork from different breeds.

(a) PLS-DA of samples. (b) Loading scatter plot. (c) VIP of aroma compounds. (d) Aroma marker. NBP, LAP, JUP, WUP, and MIP represent the roasted pork from the corresponding pig breeds.

To screen for potential aroma markers capable of discriminating the roasted pork from different breeds, the compounds with VIP > 1 and p < 0.05 were utilized (Liu, Liu, et al., 2023; Liu, Piao, et al., 2023). As shown in Fig. 5c, a total of 26 compounds met the VIP > 1 criterion, yet only one compound, namely 3,5-diethyl-2-methylpyrazine, was identified as a discriminative marker. The concentration of 3,5-diethyl-2-methylpyrazine was highest in the roasted pork from MIP, followed by that from LAP and WUP, while JUP samples exhibited the lowest level (Fig. 5d). This aligns with previous report, where pyrazines, such as 2,3-dimethylpyrazine, were identified as key markers distinguishing pork subjected to different roasting methods (Liu et al., 2024). This further demonstrates that the PLS-DA successfully differentiates the boiled pork from five typical pig breeds with aroma discrepancies (Chen et al., 2024). These differences may stem from varying levels of Maillard reaction precursors, such as glycine and glucose, in the raw meat of different breeds (Zhang et al., 2022).

4. Conclusion

The MIP proved most suitable for roasting among the pork varieties evaluated, primarily due to its higher levels of key aroma compounds, such as pyrazines. The roasted pork from NBP and WUP also exhibited pronounced roasty and meaty notes, which were significantly stronger than those of JUP and LAP. The 3,5-diethyl-2-methylpyrazine was screened as a potential marker for discriminating the roasted pork from different breeds, providing a practical tool for selecting breeds best suited to roasting. The combination of GC-IMS, GC-O-MS, and GC × GC–MS, integrated with PLS-DA, demonstrated excellent capability in distinguishing aroma fingerprints of roasted pork from different breeds, with clear separation and identification of unique markers. While the findings offer a promising framework for breed selection, the validation with larger datasets across diverse pig populations is needed to strengthen the generalizability of the results. Additionally, the potential marker, 3,5-diethyl-2-methylpyrazine, identified for distinguishing roasted pork from different breeds has not yet undergone extensive verification. Future studies should include a greater number of samples to confirm the reliability and robustness of this marker. Our future work will also focus on breed-specific differences in pyrazine precursors and their thermal conversion pathways. For meat processing industries, MIP is currently recommended as the preferred raw material for producing high-quality roasted pork products.

CRediT authorship contribution statement

Xinhe Zhang: Writing – original draft, Resources, Investigation. Jingyu Li: Writing – original draft, Resources, Investigation. Wenjing Li: Validation, Resources, Investigation. Shuqi Zhao: Formal analysis, Data curation. Chanchan Sun: Writing – review & editing. Chengyu Zeng: Writing – review & editing. Cheng Li: Writing – review & editing. Jiangyan Yu: Software. Fengxue Zhang: Visualization. Junke Li: Visualization, Methodology. Huan Liu: Supervision, Project administration, Methodology, Funding acquisition, Conceptualization.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

This study has been supported by Ludong University Program (20230044) and the Innovation Project for Graduate Students of Ludong University (IPGS2025-077).

Data availability

Data will be made available on request.

References

  1. Adams A., Kitryte V., Venskutonis R., De Kimpe N. Model studies on the pattern of volatiles generated in mixtures of amino acids, lipid-oxidation-derived aldehydes, and glucose. Journal of Agricultural and Food Chemistry. 2011;59(4):1449–1456. doi: 10.1021/jf104091p. [DOI] [PubMed] [Google Scholar]
  2. Akcan T., Estévez M., Rico S., Ventanas S., Morcuende D. Hawberry (Crataegus monogyna Jaqc.) extracts inhibit lipid oxidation and improve consumer liking of ready-to-eat (RTE) pork patties. Journal of Food Science and Technology. 2017;54(5):1248–1255. doi: 10.1007/s13197-017-2578-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Barbosa-Pereira L., Rojo-Poveda O., Ferrocino I., Giordano M., Zeppa G. Assessment of volatile fingerprint by HS-SPME/GC-qMS and E-nose for the classification of cocoa bean shells using chemometrics. Food Research International. 2019;123:684–696. doi: 10.1016/j.foodres.2019.05.041. [DOI] [PubMed] [Google Scholar]
  4. Chen X., Liu H., Li C., Xu Y., Xu B. Revealing the characteristic aroma and boundary compositions of five pig breeds based on HS-SPME/GC-O-MS, aroma recombination and omission experiments. Food Research International. 2024;178 doi: 10.1016/j.foodres.2024.113954. [DOI] [PubMed] [Google Scholar]
  5. Duan S., Tian Z., Zheng X., Tang X., Li W., Huang X. Characterization of flavour components and identification of lipid flavour precursors in different cuts of pork by phospholipidomics. Food Chemistry. 2024;458 doi: 10.1016/j.foodchem.2024.139422. [DOI] [PubMed] [Google Scholar]
  6. Gąsior R., Wojtycza K., Majcher M.A., Bielińska H., Odrzywolska A., Bączkowicz M., Migdał W. Key aroma compounds in roasted white kołuda goose. Journal of Agricultural and Food Chemistry. 2021;69(21):5986–5996. doi: 10.1021/acs.jafc.1c01475. [DOI] [PubMed] [Google Scholar]
  7. Han D., Zhang C., Fauconnier M.L., Mi S. Characterization and differentiation of boiled pork from Tibetan, Sanmenxia and Duroc × (Landrac × Yorkshire) pigs by volatiles profiling and chemometrics analysis. Food Research International. 2020;130 doi: 10.1016/j.foodres.2019.108910. [DOI] [PubMed] [Google Scholar]
  8. Heck R.T., Fagundes M.B., Cichoski A.J., de Menezes C.R., Barin J.S., Lorenzo J.M.…Campagnol P.C.B. Volatile compounds and sensory profile of burgers with 50% fat replacement by microparticles of chia oil enriched with rosemary. Meat Science. 2019;148:164–170. doi: 10.1016/j.meatsci.2018.10.017. [DOI] [PubMed] [Google Scholar]
  9. Hua W., Liu H., Fei Q., Wu J., Wei X., Ebaid M., Tao R., Liu D., Gai S. Formation of volatile compounds in mutton during air fryer roasted mutton by means of GC-MS and GC-IMS. Food Research International. 2025;211 doi: 10.1016/j.foodres.2025.116404. [DOI] [PubMed] [Google Scholar]
  10. Ji C., Wu B., Gao S., Wang Y. Impact of roasting time on the color, protein, water distribution and key volatile compounds of pork. Journal of Food Composition and Analysis. 2024;136 doi: 10.1016/j.jfca.2024.106787. [DOI] [Google Scholar]
  11. Leni G., Rocchetti G., Bertuzzi T., Abate A., Scansani A., Froldi F., Prandini A. Volatile compounds, gamma-glutamyl-peptides and free amino acids as biomarkers of long-ripened protected designation of origin Coppa Piacentina. Food Chemistry. 2024;440 doi: 10.1016/j.foodchem.2023.138225. [DOI] [PubMed] [Google Scholar]
  12. Li J., Zhang Y., Zhang R., Yang R., Ma Q., Wang Z., Li P., Xing J., Gao P., Liu H., Gong H. Unraveling the formation mechanism of aroma compounds in pork during air frying using UHPLC-HRMS and Orbitrap Exploris GC-MS. Food Research International. 2024;192 doi: 10.1016/j.foodres.2024.114816. [DOI] [PubMed] [Google Scholar]
  13. Li W., Chen Y., Blank I., Li F., Li C., Liu Y. GC × GC-ToF-MS and GC-IMS based volatile profile characterization of the Chinese dry-cured hams from different regions. Food Research International. 2021;142 doi: 10.1016/j.foodres.2021.110222. [DOI] [PubMed] [Google Scholar]
  14. Liu H., Liu D., Suleman R., Gao P., Li P., Xing J., Ma Q., Hamid N., Wang P., Gong H. Understanding the role of lipids in aroma formation of circulating non-fried roasted chicken using UHPLC-HRMS-based lipidomics and heat transfer analysis. Food Research International. 2023;173 doi: 10.1016/j.foodres.2023.113370. [DOI] [PubMed] [Google Scholar]
  15. Liu H., Ma Q., Xing J., Li P., Gao P., Hamid N., Wang Z., Wang P., Gong H. Exploring the formation and retention of aroma compounds in ready-to-eat roasted pork from four thermal methods: A lipidomics and heat transfer analysis. Food Chemistry. 2024;431 doi: 10.1016/j.foodchem.2023.137100. [DOI] [PubMed] [Google Scholar]
  16. Liu H., Wang Z., Zhang D., Shen Q., Pan T., Hui T., Ma J. Characterization of key aroma compounds in Beijing roasted duck by gas chromatography-olfactometry-mass spectrometry, odor-activity values, and aroma-recombination experiments. Journal of Agricultural and Food Chemistry. 2019;67(20):5847–5856. doi: 10.1021/acs.jafc.9b01564. [DOI] [PubMed] [Google Scholar]
  17. Liu X., Piao C., Ju M., Zhang J., Zhang W., Cui F., Li G., Cui M. Effects of low salt on lipid oxidation and hydrolysis, fatty acids composition and volatiles flavor compounds of dry-cured ham during ripening. LWT- Food Science and Technology. 2023;187 doi: 10.1016/j.lwt.2023.115347. [DOI] [Google Scholar]
  18. Liu Y., Liu C., Sun L., Li M., Zhu Y., Deng W., Yu J., Zhang W., Song Z. Investigating flavor and quality characteristics in Chinese bacon from different regions using integrated GC-IMS, electronic sensory assessment, and sensory analysis. Meat Science. 2025;220 doi: 10.1016/j.meatsci.2024.109709. [DOI] [PubMed] [Google Scholar]
  19. Nie R., Wang Z., Liu H., Wei X., Zhang C., Zhang D. Investigating the impact of lipid molecules and heat transfer on aroma compound formation and binding in roasted chicken skin: A UHPLC-HRMS and GC-O-MS study. Food Chemistry. 2024;447 doi: 10.1016/j.foodchem.2024.138877. [DOI] [PubMed] [Google Scholar]
  20. Pan Q., Shao X., Xiao Q., Gu Q., Chen C., Xu B., Li P. Revealing the flavor changes of spiced beef under different thermal treatment temperatures: A complementary approach with GC-IMS and GC-O-MS. Food Chemistry. 2025;473 doi: 10.1016/j.foodchem.2025.143074. [DOI] [PubMed] [Google Scholar]
  21. Piochi M., Nervo C., Savo F., Chirilli C., Brunori A., Torri L. Firewood as a tool to valorize meat: A sensory and instrumental approach to grilled veal, lamb, and pork meat. Food Research International. 2024;192 doi: 10.1016/j.foodres.2024.114719. [DOI] [PubMed] [Google Scholar]
  22. Ruan J., Wu Z., Xu J., Yu Y., Tang Y., Xie X., Chen J., Wang Z., Zhang D., Tang J., Li H. Effects of replacement partial sodium chloride on characteristic flavor substances of bacon during storage based on GC×GC-MS and non-targeted metabolomics analyses. Food Chemistry. 2023;428 doi: 10.1016/j.foodchem.2023.136805. [DOI] [PubMed] [Google Scholar]
  23. Schieberle P. 1995. New developments in methods for analysis of volatile flavor compounds and their precursors; pp. 403–431. [Google Scholar]
  24. Shi H., Gao R., Liu H., Wang Z., Zhang C., Zhang D. Qualitative and quantitative assessment of key aroma compounds, advanced glycation end products and heterocyclic amines in different varieties of commercially roasted meat products. Food Chemistry. 2024;436 doi: 10.1016/j.foodchem.2023.137742. [DOI] [PubMed] [Google Scholar]
  25. Sun X., Yu Y., Saleh A.S.M., Yang X., Ma J., Gao Z.…Wang Z. Characterization of aroma profiles of chinese four most famous traditional red-cooked chickens using GC-MS, GC-IMS, and E-nose. Food Research International. 2023;173 doi: 10.1016/j.foodres.2023.113335. [DOI] [PubMed] [Google Scholar]
  26. Tian X., Li Z., Chao Y., Wu Z., Zhou M., Xiao S., Zeng J., Zhe J. Evaluation by electronic tongue and headspace-GC-IMS analyses of the flavor compounds in dry-cured pork with different salt content. Food Research International. 2020;137 doi: 10.1016/j.foodres.2020.109456. [DOI] [PubMed] [Google Scholar]
  27. Totlani V.M., Peterson D.G. Reactivity of epicatechin in aqueous glycine and glucose Maillard reaction models quenching of C2, C3, and C4 sugar fragments. Journal of Agricultural and Food Chemistry. 2005;53(10):4130–4135. doi: 10.1021/jf050044x. [DOI] [PubMed] [Google Scholar]
  28. Wang Q., Gao H., Fu Y., Chen Y., Song G., Jin Z., Zhang Y., Yin J., Yin Y., Xu K. Comprehensive characterization of the differences in metabolites, lipids, and volatile flavor compounds between Ningxiang and Berkshire pigs using multi-omics techniques. Food Chemistry. 2024;457 doi: 10.1016/j.foodchem.2024.139807. [DOI] [PubMed] [Google Scholar]
  29. Wang X., Rogers K.M., Li Y., Yang S., Chen L., Zhou J. Untargeted and targeted discrimination of honey collected by Apis cerana and Apis mellifera based on volatiles using HS-GC-IMS and HS-SPME-GC-MS. Journal of Agricultural and Food Chemistry. 2019;67(43):12144–12152. doi: 10.1021/acs.jafc.9b04438. [DOI] [PubMed] [Google Scholar]
  30. Wang X., Wang X., Zhang X., Liu S., Yu J., Cui H.…Ho C.T. Changes of lipid oxidation, volatile and taste-active compounds during pan-heating of pork belly. Food Research International. 2023;172 doi: 10.1016/j.foodres.2023.113106. [DOI] [PubMed] [Google Scholar]
  31. Wei G., Li X., Wang D., Huang W., Shi Y., Huang A. Insights into free fatty acid profiles and oxidation on the development of characteristic volatile compounds in dry-cured ham from Dahe black and hybrid pigs. LWT- Food Science and Technology. 2023;184 doi: 10.1016/j.lwt.2023.115063. [DOI] [Google Scholar]
  32. Wu H., He Z., Yang L., Li H. Generation of key aroma compounds in fat and lean portions of non-smoked bacon induced via lipid pyrolysis reaction. Food Chemistry. 2024;437(1) doi: 10.1016/j.foodchem.2023.137684. [DOI] [PubMed] [Google Scholar]
  33. Wu W., Zhan J., Tang X., Li T., Duan S. Characterization and identification of pork flavor compounds and their precursors in Chinese indigenous pig breeds by volatile profiling and multivariate analysis. Food Chemistry. 2022;385 doi: 10.1016/j.foodchem.2022.132543. [DOI] [PubMed] [Google Scholar]
  34. Yan K., Kong J., Yu L., Yang J., Zeng X., Bai W., Qian M., Dong H. Flavor evolution and identification of the warmed-over flavor (WOF) in pre-cooked goose meat by means of HS-SPME-GC-MS and GC-IMS. Food Chemistry. 2025;481 doi: 10.1016/j.foodchem.2025.143979. [DOI] [PubMed] [Google Scholar]
  35. Zhang R., Zhang Y., Sun Y., Yu H., Yang F., Guo Y., Xie Y., Yao W. High-intensity ultrasound promoted the aldol-type condensation as an alternative mean of synthesizing pyrazines in a Maillard reaction model system of D-glucose-13C6 and L-glycine. Ultrasonics Sonochemistry. 2022;82 doi: 10.1016/j.ultsonch.2022.105913. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. Zhao X., Lai B., Jiang Y., Sun X., Luo Z., Ge Q., Chen J., Yu H. Characterization of flavor profiles of water-boiled pork meatballs at different ultrasonic powers using solid-phase microextraction gas chromatography-mass spectrometry combined with electronic nose. Meat Science. 2025;222 doi: 10.1016/j.meatsci.2025.109756. [DOI] [PubMed] [Google Scholar]
  37. Zhou L., Ren Y., Shi Y., Zhao L., Tian H., Feng X., Li J., Yang Y., Xing W., Yu Y., Zhao Q., Zhang J., Tang C. Investigation on the pro-aroma generation effects of fatty acids in beef via thermal oxidative models. Food Chemistry: X. 2025;26 doi: 10.1016/j.fochx.2025.102291. [DOI] [PMC free article] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Data Availability Statement

Data will be made available on request.

Articles from Food Chemistry: X are provided here courtesy of Elsevier

RESOURCES