Chinese Bacon Research Articles

Investigating flavor and quality characteristics in Chinese bacon from different regions using integrated GC-IMS, electronic sensory assessment, and sensory analysis

To investigate the variance in the quality and flavor profiles of bacon from different regions, gas chromatography-ion mobility spectrometry and electronic sensory techniques (including electronic nose and tongue [e-nose and e-tongue, respectively]) were employed for the flavor analysis of the sourced bacon samples. Both the e-nose and e-tongue successfully distinguished the aromas and flavors of different bacon varieties. Additionally, organic sulfides, aromatic benzenes, and short-chain alkanes, were more abundant in different bacon types. Employing GC-IMS technology, identified 52 volatile flavor compounds within diverse bacon samples, culminating in the establishment of a distinct fingerprint for each individual sample. The relative odor activity value identified 1-propene-3-methylthio, 2-heptanone, phenylacetaldehyde, furfuryl methyl sulfide, and 1-octene as the primary contributors to bacon flavor. These flavor substances were the main cause of the differences in bacon flavor in different regions. The interaction of volatile flavor compounds resulted in notable disparities between the odor profiles detected using the e-nose and e-tongue, even among bacon with similar volatile flavor constituents. In addition, the color and texture of the bacon varied significantly. Bacon from HB (Hubei), YN (Yunnan), and CQ (Chongqing) showed darkness in color. Meanwhile, the hardness of bacon from HN (Hunan), HB (Hubei), and SC (Sichuan) was relatively low. These results not only provide theoretical and technical insights for bacon flavor identification and control but also offer a foundation for consumers to make informed choices when purchasing bacon.

Astral-based DIA proteomics explored the flavor enhancement mechanism of Chinese traditional smoked bacon by staphylococcal co-fermentation

The proteolysis pattern during mixed fermentation of Staphylococcus cohnii WX-M8 and S. saprophyticus MY-A10 on Chinese bacon was still unknown. In this study, the changing laws of protein degradation products during staphylococcal mixed fermentation were analyzed, followed by an investigation of endogenous enzymes and cellular components, and finally an examination of flavor profiles. Results indicated that mixed fermentation improved protein degradation and promoted the production of peptides and free amino acids (FAAs). Proteolysis of S. saprophyticus MY-A10 was non-specific, and it promoted protein degradation by cooperating with cathepsin L1. S. cohnii WX-M8 was specific and acted mainly with calpain-3 in the thin filament. The fulfillment of S. cohnii WX-M8 function was enhanced in the presence of S. saprophyticus MY-A10. Mixed fermentation showed synergism with endogenous peptidases in degrading peptides to small-molecule peptides or FAAs and complementarity with endogenous dehydrogenases in converting FAAs to volatile organic compounds (VOCs).

Characterizing the composition of volatile compounds in different types of Chinese bacon using GC–MS, E-nose, and GC–IMS

Chinese bacon is highly esteemed by consumers worldwide due to its unique aroma. The composition of volatile organic compounds (VOCs) varies significantly among different types of Chinese bacon. This study analyzed the VOCs of Chinese bacon from Sichuan, Hunan, Guangxi, and Shaanxi provinces using gas chromatography-mass spectrometry (GC–MS), an electronic nose (E-nose), and gas chromatography-ion mobility spectrometry (GC–IMS). The results demonstrate that the combination of GC–MS and GC–IMS effectively distinguishes Chinese bacon from different regions. Notably, Guangxi bacon lacks a smoky aroma, which sets it apart from the other types. However, it contains many esters that play a crucial role in its flavor profile. In contrast, phenols, including guaiacol, which is typical in smoked bacon, were present in the bacon from Sichuan, Hunan, and Shaanxi but were absent in Guangxi bacon. Furthermore, Hunan bacon exhibited a higher aldehyde content than Sichuan bacon. 2-methyl-propanol and 3-methyl-butanol were identified as characteristic flavor compounds of Zhenba bacon. This study provides a theoretical foundation for understanding and identifying the flavor profiles of Chinese bacon. Using various analytical techniques to investigate the flavor compounds is essential for effectively distinguishing bacon from different regions.

New insights into the dominance of mixed fermentation of Staphylococcus cohnii and Staphylococcus saprophyticus in Chinese bacon: Complete genomic and comparative genomic perspectives

Previous studies have demonstrated that Staphylococcus cohnii WX_M8 and S. saprophyticus MY_A10 significantly enhanced the flavor of Chinese bacon in a mixed fermentation. However, due to the complexity of the processing, the contribution of the bacteria is deceptive when investigating only the phenotypic changes at the time of fermentation. In order to clarify the metabolic mechanisms of mixed fermentation, a technological characterization, whole genome and comparative genomics analysis, and metabolites were approached in this study. Results showed that differences in tolerance characteristics existed between WX_M8 and MY_A10. And the genomes of both the two strains consisted of one chromosome and four circular plasmids. Their genome sizes were 2.74 Mp and 2.62 Mp, the GC contents were 32.45% and 33.18%, and the predicted coding genes (CDS) were 2564 and 2541, respectively. Based on the annotation of gene functions and assessment of metabolic pathways in the KEGG database, WX_M8 and MY_A10 strains were found to harbor complete protein degradation and amino acid metabolic pathways, pyruvate and butanol metabolic pathways, and isoleucine metabolic pathways, and their diverse enzyme-encoding genes superimposed the metabolic functions, whereas the alcohol dehydrogenase genes, adh and frmA, achieved complementary functions in the production of esters. Comparative genomics analysis revealed a diversity of encoding genes of aminotransferases and a greater metabolism for sulfur-containing amino acids, aromatic amino acids, and branched-chain amino acids in the mixed fermentation of strains WX_M8 and MY_A10. Metabolites analysis showed that MY_A10 focused on the production of soluble peptides and free amino acids (FAAs), while WX_M8 focused on volatile organic compounds (VOCs), resulting in a significant enhancement of the flavor of Chinese bacon when the two were mixed fermented. This result may provide direction for strains WX_M8 and MY_A10 to be used as starter cultures and targeted to regulate flavor.

Effect of staphylococci fermentation and their synergistic Lactobacillus on the physicochemical characteristics and nonvolatile metabolites of Chinese bacon

The impacts of Staphylococcus cohnii, S. saprophyticus and their synergistic Lactobacillus plantarum on the quality and flavor of Chinese bacon were investigated by monitoring the physicochemical characteristics and characterizing metabolites with non-targeted metabolomics. Results showed that S. cohnii could increase the tenderness and decrease the oxidation of muscle, while S. saprophyticus stabilized the springiness and increased the proteolysis. The metabolites produced by the co-fermentation of S. cohnii and S. saprophyticus showed a higher hierarchy, then exhibited the highest hierarchy in synergy with L. plantarum. The promising flavor may be related to the arginine biosynthesis, nicotinic acid and nicotinamide metabolism, and pyrimidine metabolism pathways. Staphylococcus contributed to flavor by promoting the accumulation of di- and tripeptides and activating the amino acid metabolic pathway through arginine metabolism. These findings provide thoughts for understanding the fermentation mechanism of Staphylococcus and the targeted modulation of the flavor of Chinese bacon.

Staphylococcus inoculation enhances the sensorial attributes of Chinese bacon by coordinating the composition of flavor compounds through amino acid metabolism

In this study, we aimed to uncover the potential underlying mechanisms of the flavor modulation of Chinese bacon by Staphylococcus. To that end, taste-enhancing S. cohnii WX-M8 and S. saprophyticus MY-A10 screened from Chinese bacon were used to investigate the effects of their individual and mixed fermentations and their synergistic fermentation with Lactobacillus plantarum BL-1 on the sensorial attributes, physicochemical properties, microbial diversity, and volatile compounds (VOCs) of Chinese bacon. Our results revealed that S. cohnii WX-M8 and S. saprophyticus MY-A10 significantly increased a* (redness) and Aw and reduced thiobarbituric acid reactive substances (TBARS) when fermented in a mixture. Moreover, they promoted the formation of esters, aldehydes (especially straight-chain aldehydes), and phenolic compounds through pathways related to amino acid metabolism, enhancing sensorial attributes. While synergistic fermentation with L. plantarum BL-1 resulted in an improved a* (redness) of Chinese bacon, and the increased microbial metabolism of the carbohydrate and lipid metabolic pathways, the increase in TBARS and the higher content of acidic volatiles, led to a change in the composition of the flavor substances. The advantage of co-fermentation of Staphylococci in sensory attributes can be attributed to their capability to metabolize amino acids and associates. These findings provide insights into the role of Staphylococcus as a starter in regulating bacon flavor.

Exploring the role of bacterial communities on the quality formation and biogenic amines accumulation during ripening and storage of dry-cured Chinese bacon (Larou).

The online version contains supplementary material available at 10.1007/s10068-023-01472-1.

Isolation, characterization, and fermentation potential of coagulase-negative Staphylococci with taste-enhancing properties from Chinese traditional bacon

No proprietary starter cultures for crafting Chinese bacon. This study aimed to isolate Coagulase-negative Staphylococci (CNS) from Chinese bacon, identify their species, and evaluate their ability to produce biogenic amines (BAs), peptides, free amino acids (FAAs), and degrade proteins. Twenty-one isolates were deficient in hemolysis, DNase, and coagulase activities, and exhibited low amino acid decarboxylase activity. Further characterization revealed 11 CNS species showing protease, lipase, or nitrate reductase activities. Specifically, S. cohnii WX-M8 was able to degrade both sarcoplasmic and myofibrillar proteins, while S. saprophyticus MY-A10 was found to only degrade myofibrillar proteins. Both were able to reduce the BAs and increase the content of peptides around day 3. The meat fermented by these two CNS contained FAAs that are more conducive to taste formation, such as Glu and Asp, and reduced the content of bitter FAAs. These findings will provide insights into the use of CNS for Chinese bacon.

Evaluation of effects of ultrasound-assisted curing on the flavor of Chinese bacon

The curing stage is of great importance in flavor formation during Chinese bacon processing. Ultrasound-assisted curing plays an essential role in the Lipid oxidation of meat products. In this study, GC–MS and electronic nose were used to analyze the influence of different power ultrasonic-assisted curing on the flavor formation of Chinese bacon. Through the analysis of phospholipid and lipase, the fundamental precursors of ultrasonic on the flavor of Chinese bacon were determined. It was found that there were differences in the flavor contour description of Chinese bacon between the ultrasonic treatment group, mainly due to the change in the W1W sensor. A total of 28 volatile compounds were detected by GC–MS, and the aldehyde content increased with ultrasonic power. PC and PE are the main flavor precursors in the curing process. This study provides a theoretical basis for improving the curing technology of Chinese bacon.

Volatile compounds comparison and mechanism exploration of non-smoked traditional Chinese bacon in Southwestern China and Eastern China

Non-smoked traditional Chinese bacon is popular in China. However, the aromas of the non-smoked bacon from Eastern China (EC bacon) and Southwestern China (SW bacon) differed significantly. This study investigated these differences and the key volatile compound formation mechanisms. A total of 175 volatile compounds were detected in the bacon samples, while 32 key aroma compounds were screened based on odor activity values (OAVs). Multivariate statistical analysis showed that ten odorants could be considered discriminative compounds, including hexanal, octanal, and 1-octen-3-ol, etc. The fatty aroma of EC bacon was mainly attributed to a higher aldehydes content, which is due to more oxidation of fatty acids. Meanwhile, the SW bacon smelled sweeter since there was more ester in the sample. The correlation analysis between the fatty acid profiles and key aroma compounds indicated that the discriminative aldehyde formation in the EC bacon was primarily attributed to oleic and linoleic acid oxidation, which were both potential biomarkers.

Integrated proteomics and metabolomics analysis revealed the mechanisms underlying the effect of irradiation on the fat quality of Chinese bacon

Irradiation increases the security and storage period of preserved Chinese bacon; nevertheless, the biological mechanisms underlying the changes in fat quality caused by irradiation are unknown. We investigated the influence of irradiation on Chinese bacon by proteomic and metabolomic. We identified 24 proteins that participated in metabolism and 40 common differential metabolites enriched in 16 signalling pathways. Correlation analysis revealed that irradiation altered 11 pathways shared between the proteome and metabolome, including two lipid metabolism pathways. Acetyl-CoA carboxylase, ACSL, octanoic acid, decanoic acid, palmitic acid, and oleic acid participated in fatty acid biosynthesis. Acyl-CoA thioesterase 1/2/4, enoyl-CoA reductase, acetyl-CoA acyltransferase 1, enoyl-CoA hydratase 2, palmitic acid, and oleic acid participated in unsaturated fatty acid biosynthesis. These findings lay the groundwork for multi-omics research on the effects of irradiation on Chinese bacon quality, assisting in assessing irradiated Chinese bacon quality, and developing effective strategies to standardise quality parameters.

Quality relationship between smoked and air-dried bacon of Sichuan-Chongqing in China: Free amino acids, volatile compounds, and microbial diversity

The quality formation of Chinese bacon is closely related to flavor compounds and microbial composition; however, the contribution of microbial to flavor has not been fully explored. Previous studies have focused on the differences in microorganisms and flavor substances in smoked bacon. Thus, this study aims to investigate the relationship among microorganisms, free amino acids (FAAs), and volatile compounds (VOCs) in bacon produced by different drying processes. We analyzed the microbial composition by sequencing the V3–V4 region of the 16S rDNA gene and the fungal ITS2 region and flavor substances using an amino acid analyzer and chromatography-mass spectrometry (GC–MS). Results of taste activity values (TVA) and partial least squares discriminant analysis (PLS-DA) revealed that the flavor components of the two types of bacon had general and specific characteristics, with the key FAAs (glutamic acid, lysine, and alanine) being comparable and the key VOCs being dissimilar. Based on non-metric multidimensional scaling (NMDS) and linear discriminant analysis effect size (LefSe), bacteria had more biomarkers than fungi. Correlation analysis demonstrated that microorganisms, particularly bacteria (Staphylococcus and Salinivibrio), are crucial in regulating and shaping the flavor of bacon. Some sub-abundance of bacteria such as Kocuria enrich the flavor of bacon. These findings indicate that the simultaneous fermentation of multiple microorganisms is conducive to the recreation of the artisan flavor of Chinese bacon.

Study on the roles of microorganisms and endogenous enzymes in the evolution of metabolic characteristics of lean portion during traditional Chinese bacon processing

This study revealed the roles of microorganisms and endogenous enzymes in evolution of the metabolic characteristics of the lean portion of traditional Chinese bacon by exploring the changes in microbial succession, metabolic characteristics, lipid oxidation, lipid hydrolysis, lipoxygenase activity, lipohydrolase activity, protein degradation, and environmental factors during processing. The results showed that Proteobacteria and Firmicutes were the dominant phyla in the lean portion of traditional Chinese bacon, and 16 core genera (relative abundance > 1 %) were identified at the genus level. Significant differences were observed in the metabolic characteristics of different samples. A total of 23 differential metabolites were identified in positive and negative ion modes (P < 0.05, variable importance in the projection > 1.5). Peroxide value (POV), thiobarbituric acid reactive substances value (TBARS), proteolysis index (PI) and the degree of lipid hydrolysis increased during the processing. Phospholipids were the main hydrolysis substrates. Lipoxygenase activity increased first and then decreased, while lipohydrolase activity decreased gradually. The results of canonical correspondence analysis indicated that the salt content was the main environmental factor affecting the microbial composition. The results of Spearman correlation analysis and comprehensive discussion showed that the metabolic characteristics of the lean portion of traditional Chinese bacon during the curing period were mainly due to the catalysis of the endogenous enzymes in meat and the extracellular enzymes secreted by bacteria such as Brochothix, Acinetobacter, Psychrobacter, etc. The extracellular enzymes secreted by Salinivibrio, Vibrio, and Staphylococcus in light-fermented meat and final meat might have important contributions to the metabolic characteristics.

Enhanced preservation effects of clove (Syzygium aromaticum) essential oil on the processing of Chinese bacon (preserved meat products) by beta cyclodextrin metal organic frameworks (β-CD-MOFs)

The applications of clove (Syzygium aromaticum) essential oil (CEO) are limited by instability, low solubility and high volatility. The present study aimed to improve the properties of CEO by microencapsulation with cyclodextrin metal organic frameworks (β-CD-MOFs) to enhance the preservation effects on Chinese bacon (preserved meat products). The microencapsulated CEO by β-CD-MOFs (CEO/β-CD-MOFs) not only did not inhibit the antioxidant activities of CEO, but also showed significant improvements on their ROS scavenging abilities and thermo-/pH-stabilities. The increases of superoxide anion and hydroxyl radical scavenging activities were 20.74% and 12.84%, respectively. In addition, less lipid oxidation, including malondialdehyde (MDA) contents and peroxide values (POV), of Chinese bacon was found after the CEO/β-CD-MOFs treatment than CEO and synthetic antioxidant (BHT) treatments. These results suggested the enhanced preservation effects of microencapsulated CEO on the processing of Chinese bacon and the great potential of β-CD-MOFs as carriers for essential oils in food industry applications.

Comprehensive insights into the evolution of microbiological and metabolic characteristics of the fat portion during the processing of traditional Chinese bacon

Both lean meat and fat together contribute to the consumer impression of traditional Chinese bacon. The quality of this meat product is mainly dependent on numerous biochemical reactions and microbes. For the first time, this study reveals the microbial community succession and metabolic characteristics of the fat portion during the processing of traditional Chinese bacon by high-throughput sequencing and untargeted metabolomics (ultra-high performance liquid chromatography, UHPLC). The results showed that Proteobacteria and Firmicutes were the predominant bacterial phyla in traditional Chinese bacon. At the genus level, 15 core genera (relative abundance >1%) were identified, including Salinivibrio, Staphylococcus, Brochothrix, Vibrio, Psychrobacter, Acinetobacter, Carnobacterium, Aeromonas, Pseudomona, Cobetia, Macrococcus, Enterobacter, Kocuria, unclassified-f-Vibrionaceae, and Empedobacter. Distinct separation between different groups were identified by principal component analysis, revealing significant differences in the metabolic characteristics of different samples. A total of 262 metabolites were identified, and most of the metabolites belonged to lipids and lipid-like molecules, of which 60 were identified as differential metabolites. Results of correlation analysis indicated that some differential metabolites were significantly positively correlated with dominant bacteria, such as Salinivibrio, Vibrio, Cobetia and Staphylococcus, which reinforced the fact that microorganisms have an indispensable role in the quality formation of traditional Chinese bacon.

Changes in volatile organic compounds and lipid oxidation in traditional Chinese bacon during cold smoking

Abstract The smoking time of cold-smoked traditional Chinese bacon (TCB) in northeast Chongqing is not precisely controlled. In this study, the accumulation of, and changes in, volatile organic compounds (VOCs) during smoking were investigated by gas chromatography–ion mobility spectrometry (GC-IMS). Simultaneously, the lipid oxidation and sensory attributes of TCB were assessed. Thirty-nine VOCs were identified in samples, most of which were alcohols, aldehydes, ketones, and esters. Samples smoked for 12 and 15 days contained characteristic VOCs, mainly comprising phenols, esters, and heterocyclic compounds, which produce the flavor of mature TCB. Odorous substances other than characteristic VOCs reached their maximum or sub-maximum on day 12, which was consistent with the sensory assessment results. The peroxide value of TCB increased continuously with smoking; while 2-thiobarbituric acid reactive substances test (TBARS) values were at a lower level between days 9 and 12. Therefore, the recommended smoking time should be about 12 days.

Evaluation of Bacterial Diversity and Quality Features of Traditional Sichuan Bacon from Different Geographical Region

Sichuan bacon is one of the most popular types of Chinese bacon in the domestic market. High-throughput sequencing was used to characterize the bacterial diversity of 39 Sichuan bacon samples collected from 3 geographical regions. The results showed that the bacterial diversity of Sichuan bacon in different regions demonstrated certain specificity as well as similarity, and the shared OTUs were close to 81% of the total number in the basin group, mountain group, and plateau group. At the genus level, Staphylococcus is the most dominant genus among the three groups, covering 26.7%, 20.6%, and 22.7%, respectively. Beta diversity shows significant differences in bacterial compositions in different geographic regions, especially for Pseudomonas, Brochothrix, Lactobacillus, Lactococcus, and Enterococcus. Meanwhile, some physicochemical characteristics were analyzed, and a significant difference (p &lt; 0.05) among the three regions was shown in the Aw, pH, and nitrite content, which were significantly correlated with undesired bacteria. This study provides insights into the understanding of the role of bacterial communities in the microbial safety and quality improvement of Sichuan bacon.

The strategy of biopreservation of meat product against MRSA using lytic domain of lysin from Staphylococcus aureus bacteriophage

Staphylococcus aureus is a notorious foodborne pathogen capable of producing various toxins including heat-stable enterotoxin, forming biofilm, evolving to multidrug-resistant strains including methicillin-resistant S. aureus (MRSA) against antibiotics, and threatening public health, of which the biocontrol garners increasing interest from both researchers and food industry. Recently, bacteriophage lysins, degrading cell wall that is indispensable for bacteria, are deemed promising antimicrobial agents. In this work, the lysin LysGH15 from MRSA phage GH15 demonstrated a broad lytic spectrum to S. aureus, cleaving six test S. aureus strains including MRSA, as well as its catalytic domain CHAPLysGH15 alone. LysGH15 and CHAPLysGH15 exhibited different characteristics to one MRSA strain (MRSA 2701), reaching the highest activity at different conditions (35 °C and pH of 6.0 for LysGH15, 40 °C and pH of 9.0 for CHAPLysGH15). Especially, the different sensitivities of two enzymes to NaCl concentration in foods were found, where 500 mM of NaCl was indispensable for LysGH15's efficient lytic action while high concentration of NaCl impaired the activity of CHAPLysGH15. The susceptibility to NaCl and high optimal antimicrobial pH (9.0) of CHAPLysGH15 enabled its application in low-salt and non-acid foods such as fresh meat, of which the preservation is always an issue in food industry. LysGH15 and CHAPLysGH15 presented a promising biocontrol effect in high-salt food and low-salt food, respectively. The 0.4 nmol/cm2 of LysGH15 and CHAPLysGH15 were applied in Chinese bacon and fresh pork, where they could efficiently decrease MRSA from 104 to 0 CFU/cm2 after 2 h (LysGH15 to bacon, and CHAPLysGH15 to fresh pork).

Effects of partial replacement of NaCl with KCl on bacterial communities and physicochemical characteristics of typical Chinese bacon

This work aimed to determine the effects of partial substitution of NaCl with 0% (control), 30%, 50%, and 70% of KCl on the bacterial communities, proteolysis and lipid oxidation of Chinese bacon during processing. The proportion of genus Lactobacillus increased from 22.45% (fresh meat) to 72.78%, 81.64%, 76.53% and 85.63% at the end of processing for 0%, 30%, 50% and 70% KCl replacement samples, respectively. During the processing, Lactobacillus gradually became the dominant one, and higher the KCl ratio, more rapid was the process. After salting, the TBARS of control was markedly higher (P < 0.05) than that of the others, while a similar lipid oxidation level (P > 0.05) was observed at the end of processing for different groups. After salting, there was no difference in total free amino acids (TFAA) content among four treatments (P > 0.05), whereas KCl replacement samples shared significantly higher (P < 0.05) values than control at the end of processing. Redundancy analysis and Pearson correlation showed positive correlation between Lactobacillus versus TBARS and TFAA. Partial replacement of NaCl with KCl could, directly or subsequently by promoting the growth of Lactobacillus, influence proteolysis and lipid oxidation over the manufacturing process.

NMR-based metabolomics profiling of no-added-nitrite Chinese bacon (unsmoked) during processing.

Variations in the taste quality of no-added-nitrite Chinese bacon (unsmoked) during processing were investigated using 1 H-NMR and multivariate data analysis. The results showed that 21 metabolites were dominant during processing, which involved marinating, air-drying, fermentation, and baking, including amino acids, sugars, organic acids, nucleic acids and their derivatives, and alkaloids. The contents of isoleucine, leucine, valine, alanine, acetate, glutamate, succinate, glycine, sucrose, tyrosine, and phenylalanine increased continuously throughout the process. The lactate, creatine, carnosine, betaine, taurine, hypoxanthine, and AMP contents all significantly increased after baking; the inosine content significantly increased after fermentation and then decreased; the histamine content significantly increased after air-drying and then decreased; and the histidine content decreased. Each processing treatment promoted taste formation in no-added-nitrite Chinese bacon (unsmoked), especially baking. The baking point owned relatively higher levels of metabolites and sensory evaluation compared to other treatments. Sensory evaluation revealed that the ultimate taste of Chinese bacon (unsmoked) at the end of baking tended toward umami (glutamate), sweetness (AMP), and sourness (lactate). The first and second principal components explained 74.0% and 13.4% of the variables, respectively. These findings indicated the potential of NMR-based metabolomics for assessing the taste quality of no-added-nitrite Chinese bacon (unsmoked), which could contribute to a better understanding of taste compound changes in meat products. PRACTICAL APPLICATION: Nitrite is commonly used in Chinese bacon (unsmoked), but excessive intake is not good for human health. Nitrite has been replaced with nitrite substitutes to prepare no-added-nitrite Chinese bacon (unsmoked). The metabolites of no-added-nitrite Chinese bacon (unsmoked) were detected to determine the key treatment that contributes to the formation of taste during processing. This study determined the main taste components of no-added-nitrite Chinese bacon (unsmoked) and its formation process, which provides new insight into the production and characteristics of flavor in Chinese bacon (unsmoked).