A peptidomic approach of meat protein degradation in a low-sodium fermented sausage model using autochthonous starter cultures

Strategies to Reduce Salt Content: PDO and PGI Meat Products Case

The reduction of sodium chloride (NaCl) content, commonly known as salt, in processed meat products is one of the objectives of health organizations and government authorities to achieve healthier products. This reformulation of traditional meat products with protected designations poses more constraints, as they have a more consolidated quality image and less margin for change, since consumers appreciate the products for their unique sensory characteristics. The aim of this work is to present some of the strategies that have been explored to obtain meat products with low sodium content. Information related to the characteristics of traditional meat products with quality marks and geographical indications in different studies is discussed in opposition to the information recorded in their product specifications. It was found that the product specifications of meat products with Portuguese Protected Designation of Origin (PDO) and Protected Geographical Indication (PGI) show a wide variation in the NaCl content, much higher than the recommended values. Thus, one of the requirements to be implemented will be the parameterization of NaCl levels and their monitorization by control and certification organizations as a way to ensure product quality. It is also urgent to examine whether healthy innovation strategies may affect the quality of traditional PDO or PGI meat products and whether they can be included in the respective product specifications.

Influence of sonication pretreatment on antiradical and anti-ACE activity of protein hydrolysates from fermented pork loins

The aim of this study was to assess whether ultrasound treatment (sonification time: 5, 15, and 30 min; constants: ∼40 kHz, ∼2.5 W cm2) can be applied prior to hydrolysis to enhance the anti-radical and angiotensin converting enzyme inhibiting (anti-ACE) effect of the hydrolysates from fermented pork loins. Enzymatic hydrolysis was performed using pepsin, followed by pancreatin. The influence of meat matrix on the course of hydrolysis, shaped using a lactic acid bacteria (LAB)-based starter culture, was also analyzed. It was found that proteases caused a systematic increase in the content of peptides, while pancreatin limited the peptide content in the protein hydrolysate from the loins subjected to spontaneous fermentation. Moreover, for these tests, sonication time had a negligible effect on the peptides content of the hydrolysates. On the other hand, for the sample of LAB-fermented products, both sonication time and stage of hydrolysis promoted the biological activity of the hydrolysates. Samples from the LAB-fermented meat had more peptides at the stage of digestion with pepsin and pancreatin, exhibiting much faster antiradical and anti-ACE activity compared to the control sample. The obtained results suggest that the use of LAB promotes the release of antiradical peptides during the two-step enzymatic hydrolysis, the duration of which can be shortened to achieve satisfactory biofunctionalities. Additional application of sonication pretreatment allows controlling the course of the hydrolysis, as the pro-health, biological effect of some protein-derived sequences is associated with the content of peptides.

Partial Replacement of NaCl by KCl, MgCl2 and CaCl2 Chloride Salts in the Production of Sucuk: Effects on Volatile Compounds, Lipid Oxidation, Microbiological and Sensory Properties

The effects of different chloride salt mixtures (I-control: 100% NaCl, II: 50:50-NaCl:KCl, III: 50:30:20-NaCl:KCl:MgCl2, IV: 50:30:20-NaCl:KCl:CaCl2, V: 50:30:10:10-NaCl:KCl:MgCl2:CaCl2) on the quality properties of sucuk (a dry fermented beef sausage) during ripening were investigated. Lactic acid bacteria reached 8 log cfu/g in the 3 days of fermentation in all treatments. However, salt mixtures including MgCl2 caused an increase in Micrococcus/Staphylococcus. The control group showed the lowest mean aw value at the end of ripening. The salt mixture with 20% CaCl2 showed the lowest mean pH value of 4.97. The mean TBARS value varied between 6.34 and 6.97 µmol MDA/kg but was not affected by the salt mixtures (p > 0.05). According to the results of PCA, salt mixtures I, II and III had a positive correlation in PC1, and PC1 also separated salt mixtures with CaCl2 (IV and V) from other groups. In addition, a strong positive correlation between the control and III group (50:30:20-NaCl:KCl:MgCl2) for sensory properties was determined by heatmap clustering analysis. In addition, the principal component analysis showed that the control, II, and III groups had a stronger correlation with each other for volatile compounds.

Combined effects of lipase and Lactiplantibacillus plantarum 1-24-LJ on physicochemical property, microbial succession and volatile compounds formation in fermented fish product

BACKGROUND

Studies have shown that either the addition of starter culture or enzyme can improve fermentation in fish or other products. However, little research has been carried out on the effects of coupling starter cultures with lipase on the microbial community and product quality. Suanzhayu is a Chinese fermented fish product that mainly relies on spontaneous fermentation, resulting in an unstable flavor and quality. The present study investigated the impact of lipase and Lactiplantibacillus plantarum 1-24-LJ on the quality of Suanzhayu.

RESULTS

Inoculation decreased pH and 2-thiobarbituric acid reactive substances (TBARS) values, and also helped the dominance of the strain in the ecosystem, whereas lipase addition raised TBARS values and had little effect on pH, water activity (a_w ) and microbiota. The addition of lipase and/or Lpb. plantarum increased the content of alcohols, aldehydes, ketones, esters and umami amino acids. The co-additions with the most significant effect and the total contents of volatile compounds (VCs) and free amino acids (FAAs) were 1801.92 g per 100 g and 21 357.05 mg per 100 g, respectively. Former-Lactobacillus was negatively correlated with pH, a_w and Prevotella, but positively with VCs (ethyl ester of heptanoic acid, ethyl ester of octanoic acid) and FAAs (Tyr, Phe). Furthermore, adding Lpb. plantarum 1-24-LJ alone or in combination with lipase shortened the fermentation process.

CONCLUSION

The present study provides a recommended Suanzhayu process approach for improving product quality and flavor, as well as shortening fermentation time, by adding Lpb. plantarum 1-24-LJ with or without lipase. © 2023 Society of Chemical Industry.

Molecular insights into quality and authentication of sheep meat from proteomics and metabolomics

Sheep meat (encompassing lamb, hogget and mutton) is an important source of animal protein in many countries, with a unique flavour and sensory profile compared to other red meats. Flavour, colour and texture are the key quality attributes contributing to consumer liking of sheep meat. Over the last decades, various factors from 'farm to fork', including production system (e.g., age, breed, feeding regimes, sex, pre-slaughter stress, and carcass suspension), post-mortem manipulation and processing (e.g., electrical stimulation, ageing, packaging types, and chilled and frozen storage) have been identified as influencing different aspects of sheep meat quality. However conventional meat-quality assessment tools are not able to elucidate the underlying mechanisms and pathways for quality variations. Advances in broad-based analytical techniques have offered opportunities to obtain deeper insights into the molecular changes of sheep meat which may become biomarkers for specific variations in quality traits and meat authenticity. This review provides an overview on how omics techniques, especially proteomics (including peptidomics) and metabolomics (including lipidomics and volatilomics) are applied to elucidate the variations in sheep meat quality, mainly in loin muscles, focusing on colour, texture and flavour, and as tools for authentication. SIGNIFICANCE: From this review, we observed that attempts have been made to utilise proteomics and metabolomics techniques on sheep meat products for elucidating pathways of quality variations due to various factors. For instance, the improvement of colour stability and tenderness could be associated with the changes to glycolysis, energy metabolism and endogenous antioxidant capacity. Several studies identify proteolysis as being important, but potentially conflicting for quality as the enhanced proteolysis improves tenderness and flavour, while reducing colour stability. The use of multiple analytical methods e.g., lipidomics, metabolomics, and volatilomics, detects a wider range of flavour precursors (including both water and lipid soluble compounds) that underlie the possible pathways for sheep meat flavour evolution. The technological advancement in omics (e.g., direct analysis-mass spectrometry) could make analysis of the proteins, lipids and metabolites in sheep meat routine, as well as enhance the confidence in quality determination and molecular-based assurance of meat authenticity.

Lactiplantibacillus plantarum Strains Modulate Intestinal Innate Immune Response and Increase Resistance to Enterotoxigenic Escherichia coli Infection

Currently, probiotic bacteria with not transferable antibiotic resistance represent a sustainable strategy for the treatment and prevention of enterotoxigenic Escherichia coli (ETEC) in farm animals. Lactiplantibacillus plantarum is among the most versatile species used in the food industry, either as starter cultures or probiotics. In the present work, the immunobiotic potential of L. plantarum CRL681 and CRL1506 was studied to evaluate their capability to improve the resistance to ETEC infection. In vitro studies using porcine intestinal epithelial (PIE) cells and in vivo experiments in mice were undertaken. Expression analysis indicated that both strains were able to trigger IL-6 and IL-8 expression in PIE cells in steady-state conditions. Furthermore, mice orally treated with these strains had significantly improved levels of IFN-γ and TNF-α in the intestine as well as enhanced activity of peritoneal macrophages. The ability of CRL681 and CRL1506 to beneficially modulate intestinal immunity was further evidenced in ETEC-challenge experiments. In vitro, the CRL1506 and CRL681 strains modulated the expression of inflammatory cytokines (IL-6) and chemokines (IL-8, CCL2, CXCL5 and CXCL9) in ETEC-stimulated PIE cells. In vivo experiments demonstrated the ability of both strains to beneficially regulate the immune response against this pathogen. Moreover, the oral treatment of mice with lactic acid bacteria (LAB) strains significantly reduced ETEC counts in jejunum and ileum and prevented the spread of the pathogen to the spleen and liver. Additionally, LAB treated-mice had improved levels of intestinal IL-10 both at steady state and after the challenge with ETEC. The protective effect against ETEC infection was not observed for the non-immunomodulatory TL2677 strain. Furthermore, the study showed that L. plantarum CRL1506 was more efficient than the CRL681 strain to modulate mucosal immunity highlighting the strain specific character of this probiotic activity. Our results suggest that the improved intestinal epithelial defenses and innate immunity induced by L. plantarum CRL1506 and CRL681 would increase the clearance of ETEC and at the same time, protect the host against detrimental inflammation. These constitute valuable features for future probiotic products able to improve the resistance to ETEC infection.

Correlation and Difference between Core Micro-Organisms and Volatile Compounds of Suan Rou from Six Regions of China

Suan Rou (SR), a traditional fermented meat, is widely favored by consumers due to its unique flavor and characteristics. To study the relationship between the core differential micro-organisms and differential volatile organic compounds (VOCs) of SR from six regions of China, high-throughput sequencing (HTS) and gas-chromatography−ion mobility spectrometry (GC-IMS) technologies were used to analyze the correlation between micro-organisms and VOCs in SR from Xiangxi of Hunan, Rongshui of Guangxi, Zunyi of Guizhou, Jinping of Guizhou, Congjiang of Guizhou, and Libo of Guizhou. A total of 13 core micro-organisms were identified at the genus level. Moreover, 95 VOCs were identified in the SR samples by GC-IMS analysis, with alcohols, aldehydes, ketones, and esters comprising the major VOCs among all the samples. The results showed a strong correlation (|r| > 0.8, p < 0.05) between the core differential micro-organisms and differential VOCs, including four bacteria, five fungi, and 12 VOCs. Pediococcus, Debaryomyces, Zygosaccharomyces, and Candida significantly contributed to the unique VOCs of SR.

Peptidomic Characteristic of Peptides Generated in Dry-Cured Loins with Probiotic Strains of LAB during 360-Days Aging

Peptidomics refers to the comprehensive profiling of endogenous peptides obtained from biological sources. The formation of endogenous peptides is dependent on not only endogenous factors but also exogenous factors such as microbial proteases or process conditions, including fermentation. This study analyzed the probiotic strains of Lactobacillus rhamnosus LOCK900 (LOCK), Bifidobacterium animalis ssp. lactis BB-12 (BB12), and potential probiotic Lactobacillus acidophilus Bauer Ł0938 (BAUER) to assess their ability of fermentation and peptide production in dry-cured pork loin. The peptides obtained after in vitro digestion were characterized by liquid chromatography–tandem mass spectrometry. Based on the sequences identified, the degree of similarity or differences between the peptides was determined and presented graphically on the factor plane. The charts showed that the meat products aged for 180 and 270 days were the most diverse when BB12 or BAUER were used as starter cultures. Myosin and keratin were identified as the most likely precursors of bioactive peptides in products obtained using this strain of lactic acid bacteria (LAB). The knowledge acquired from this study may contribute to the design of functional meat products as the results revealed not only the peptidogenic potential of the LAB strains indicated on their beneficial effect on the bioactivity of peptides.

Studies on Flavor Compounds and Free Amino Acid Dynamic Characteristics of Fermented Pork Loin Ham with a Complex Starter

Staphylococcus simulans and Lactobacillus plantarum screened from Guizhou specialty food were used to prepare fermented pork loin ham. The sensory qualities and flavor profiles of fermented pork loin hams from 0 to 42 days were investigated in order to reveal the dynamics of fermented pork loin ham. The results show that total free amino acids (TFAA) content reached the highest value on the 35th day, and the umami amino acids, including aspartic acid (ASP), glutamic acid (GLU), glycine (GLY), and alanine (ALA), were the main amino acids in all periods. Notably, the RV coefficient (0.875) indicates that free amino acids (FAA) are highly correlated with the sensory score of the E-tongue. In terms of the volatile compounds identified, the esters content gradually increased between 7 and 42 days, and ethyl octanoate was the most abundant compound during all periods. These esters imparted a characteristic aroma component to the fermented pork loin ham. The most important finding was that the increase in the content of esters represented by octanoic acid-ethyl ester might be related to the increase in the content of FAA with the increase in fermentation time. Both the E-nose and E-tongue showed good discrimination ability for fermented tenderloin ham with different fermentation times, which was crucial in cases with large clusters. In addition, the multiple factor analysis (MFA) indicated that the E-nose aroma value might be the key factor in distinguishing fermented pork loin ham with different fermentation times.

Dynamics and correlation of microbial community and flavor in Pixian Douban fermented with closed process of constant temperature

BACKGROUND

As a Chinese traditional flavor condiment, Pixian Douban (PXDB) is produced using a traditional open fermentation process. In this study, an experimental fermentation of PXDB was conducted at 40 °C for 90 days in a closed system, which has not been applied to PXDB production. The flavor, microbial community and correlations of the samples in the closed system were compared with those in the traditional fermentation.

RESULTS

The content of organic acids and free amino acids in the closed fermentation of constant temperature (CFCT) achieved the standards of product quality, although they were lower than those in the traditional fermentation. Of the 140 detected aroma components, 98 were shared in the two fermentation processes. Enterobacter, Bacteroides and Megamonas were the core microbial genera related to 26 flavor components in the traditional fermentation, while Pantoea was the core microbial genus related to 18 flavor components in CFCT. The CFCT has its own unique advantages over traditional fermentation in forming aromas. It produced a greater impact on the succession of fungi than those of bacteria after changing traditional fermentation to CFCT. The influence of microorganisms on the formation of flavor components was relatively more balanced in CFCT, while the changed fermentation process impacted greatly on the functions of Zygosaccharomomyces and Pichia but little on those of Sphingomonas, Megamonas and Parabacteroides.

CONCLUSION

The study indicated that it was feasible to ferment PXDB in the closed system, and provides a basis to realize controllable PXDB production. © 2020 Society of Chemical Industry.

Relationship between volatile organic compounds, free amino acids, and sensory profile of smoked bacon

Flavor is one of the most important characteristics of smoked bacon, strongly affecting its liking by consumers. The smoking process, lipid oxidation and proteolysis contribute to bacon quality through the generation of odors and flavor compounds. In this study, the relationships between free amino acids (FAAs), volatile organic compounds (VOCs) and sensory characteristics of smoked bacon stored for 60 days at 5 °C were investigated. Smoked bacon stored for 30 days was characterized by VOCs associated with the smoking process and lipid oxidation. After 30 days of storage, the bacon samples presented an increase in FAAs produced mainly by proteolysis. Smoked bacon was characterized by the attributes smoky, crunchy, salty, soft and bright. This study demonstrated that VOCs, FAAs and their interactions are responsible for generating sensory attributes and increasing overall liking.

Indigenous Microbiota to Leverage Traditional Dry Sausage Production

The main issue addressed in this review is the need for innovation in the artisanal production of dry fermented sausages-leveraging rather than discarding tradition, together with some practical strategies available to achieve it. Throughout the text, emphasis is placed on the autochthonous microbiota responsible for the identity and unique sensory characteristics of these products. The available strategies to introduce innovation in this manufacturing process rely on metabolic flexibility of microbial strains. In this sense, this review evaluates the application of several tools aimed at improving the quality and safety of artisanal dry fermented sausages focusing on the microbial community role. The most studied alternatives to enhance dry sausage production comprise the use of autochthonous starter cultures-including functional and/or probiotic strains, the production of bacteriocins, and the generation of bioactive peptides, which have been thoroughly covered herein. The purpose of this work is to review recent research about novel different strategies available for food technologists to improve safety and quality in the manufacture of dry fermented sausages. Additional support strategies-quality product registers and innovation through tradition-have been suggested as complementary actions towards a successful introduction of indigenous microbial communities into traditional dry sausage production.

Characterisation of the flavour profile of dry fermented sausages with different NaCl substitutes using HS-SPME-GC-MS combined with electronic nose and electronic tongue

The effects of different sodium substitutes on the physical and bacterial properties, flavour profile and sensory evaluation of dry fermented sausage were investigated. There were three different salt formulations, including control (C: 100%NaCl), S1 (70%NaCl and 30%KCl) and S2 (70%NaCl, 20%KCl and 10% flavour enhancers). Higher moisture content and lactic acid bacteria count, and lower pH and Staphylococcus count were observed in NaCl substitution treatments compared to the control (P < 0.05). Sixty-two volatiles were detected in sausages, and 26 compounds were regarded as key volatile compounds based on the odour activity values. The electronic tongue result and sensory evaluation showed that the taste profile of S2 treatment was similar to control treatment; and the electronic nose, volatile compound results and hierarchical cluster analysis showed that the sodium substitutes had a more significant effect on the odour profile. Overall, S2 may be an ideal low-sodium substitute to achieve a 30% reduction in NaCl and provide a better flavour profile of fermented sausages.

Synergistic effects of Lactobacillus plantarum and Staphylococcus carnosus on animal food components

Introduction. Various cultures of microorganisms have recently been used to accelerate technological processes. In this regard, it appears highly relevant to study the action of beneficial microorganisms on the components of food systems. Study objects and methods. The study objects included a model mixture of beef muscle and pork fat tissue with 2% salt, as well as a model protein. Lactobacillus plantarum and Staphylococcus carnosus were used in an amount of 1×107 CFU/g of raw material. The compositions of free amino and fatty acids, carbohydrates, and other components were analyzed by liquid and gas chromatography with mass-selective detection. Results and discussion. We studied the effect of L. plantarum and S. carnosus on protein, lipid, and carbohydrate components of food systems based on animal raw materials. We found that the combined effect of the cultures was by 25% as effective as their individual use at 4×109 CFU/kg of raw material. The three-week hydrolysis of proteins to free amino acids was almost a third more effective than when the cultures were used separately. The synergistic effect of L. plantarum and S. carnosus on fat components was not detected reliably. Free monosaccharides formed more intensively when the cultures were used together. In particular, the amount of free lactose almost doubled, compared to the cultures’ individual action. Conclusion. We described culture-caused quantitative changes in the main components of animal-based food systems: amino acids, fatty acids, carbohydrates, and basic organic compounds. Also, we identified substances that can affect the taste and aroma of final products when the cultures are used together or separately. These results make it possible to obtain products with a wide variety of sensory properties.

Co-fermentation with Lactobacillus curvatus LAB26 and Pediococcus pentosaceus SWU73571 for improving quality and safety of sour meat

Lactic acid bacteria of Lactobacillus curvatus LAB26 and Pediococcus pentosaceus SWU73571 isolated from traditional sour meat were prepared to a double-starter culture for sour meat processing. The results showed that the counts of total bacteria and lactic acid bacteria in inoculating group reached 9.37 ± 0.11 log cfu/g and 8.73 ± 0.14 log cfu/g on the 30th day, and were higher than those in natural fermentation (7.02 ± 0.11 log cfu/g and 6.93 ± 0.17 log cfu/g). Compared to natural fermentation, the double-starter culture increased the L* and a*values, amino nitrogen content, free amino acid content of sour meat significantly, and lowered the b* value, restrained the coliform count, nitrite, biogenic amines, total volatile basic nitrogen and malondialdehyde in sour meat. Moreover, the pH and water activity were reduced to 3.91 ± 0.01 and 0.831 ± 0.002, respectively. These results proved that the inoculation of double-starter culture could improve the quality and safety of sour meat. This double-starter culture has great potential for application to the manufacture of fermented meat.

Effects of starter culture inoculation on microbial community diversity and food safety of Chinese Cantonese sausages by high-throughput sequencing

Effects of starter culture composed of Lactobacillus sakei, Pediococcus pentosaceus, Staphylococcus xylosus and Staphylococcus carnosus at the ratios (w/w) of 1:1:1:1 on bacterial community diversity and food safety of Chinese Cantonese sausages were demonstrated by high-throughput sequencing technology. At genus level, spoilage organisms and pathogenic bacteria such as Vibrio spp., Acinetobacter spp., Enterobacter spp., Yersinia spp. accounted for 54.13%, 10.01%, 6.94% and 5.35% of bacterial in the initial fermentation of spontaneous sausage, and the dominant bacteria of Lactobacillus spp. reached 84.61% on day 20. Accordingly, the total proportion of Pediococcus spp., Lactobacillus spp. and Staphylococcus spp. were present higher than 98% during fermentation in fermented sausage by starter culture inoculation, and Pediococcus spp. was dominant genus and increased from 53.53 to 74.09% during whole fermentation process. Moreover, the histamine accumulation was lower 84.17% in sausage fermented by starter culture inoculation than that of spontaneous sausage, suggesting that starter culture could decrease histamine accumulation of sausages significantly (P < 0.01). These results revealed that the starter culture inoculation was conducive to improve the microbial quality and food safety of Chinese Cantonese sausages.

Detection of protein aggregation markers in raw meat and finished products

The effect of animal and plant proteases as well as starters, or starter cultures, on protein aggregates for- mation in raw pork and beef as well as meat products was studied. The proteomic analysis of raw meat revealed that animal proteases – pepsin and trypsin – caused the aggregation of isoform 2 of protein 1 containing 4.5 LIM domains. Vacuum packaged meat showed the same results during storage, while unpacking led to the acceleration of the aggregation process due to autolysis. In addition, mixed aggregated fragments, such as muscle creatine phos- phokinase and glutathione-S-transferase, actin and perilipin, and type II keratin appeared in those samples. Starters with Pediococcus pentosaceus 31 from the Russian National Collection of Industrial Microorganisms (VKPM-8901) caused myoglobin and troponin I aggregation, while the formation of soy proteins aggregates (glycinin G1 and glyci- nin A3B4) was detected in meat products as a result of the autolysis process and the use of cholesterol-lowering star- ters. All in all, proteases which cause protein aggregation may be less effective for raw meat tenderization, whereas the proteins identified may be used as quality biomarkers.

Draft Genome Sequence of Lactobacillus plantarum CRL681, Isolated from Argentinean Artisanal Fermented Sausages

Lactobacillus plantarum CRL681 was isolated from Argentinean artisanal fermented sausages. Here, the draft genome sequence of the CRL681 strain is described. The reads were assembled into contigs with a total estimated size of 3,370,224 bp. A total of 3,300 open reading frames (ORFs) were predicted, including 3,126 protein-coding sequences. The draft genome sequence of L. plantarum CRL681 will be useful for understanding the organism's metabolic activities and for biotechnological applications.

Shortening Fermentation Period and Quality Improvement of Fermented Fish, Chouguiyu, by Co-inoculation of Lactococcus lactis M10 and Weissella cibaria M3

Chouguiyu, a Chinese traditional fermented fish, is famous for its uniquely strong odor and desirable taste. However, traditional spontaneous fermentation often resulted in contamination and unstable quality of products. In this study, individual or conjunctive inoculation of two indigenous lactic acid bacteria (LAB), Lactococcus lactis M10 and Weissella cibaria M3, was tested for their effect on improving Chouguiyu's quality. It was shown that inoculation would not affect the system's pH, while increased the total bacteria count and lactic acid bacteria amounts. Matrix-assisted laser desorption/ionization time-of-flight mass (MALDI-TOF) analysis results revealed that Lactoc. lactis M10 and W. cibaria M3 could quickly occupy a dominant position in the ecosystem, and Lactoc. lactis M10 played an important role in the control of spoilage bacteria. Volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS), and biogenic amines results also showed that Lactoc. lactis M10 had a positive effect on improving the product's quality. Co-inoculation of Lactoc. lactis M10 and W. cibaria M3 could promote the formation of flavor according to the E-nose and gas chromatography-mass spectrometer (GC-MS) analyses, especially for the aroma-active and key volatile compounds. PCA plots of E-nose and hierarchical clustering analysis of GC-MS profiles revealed that the co-inoculation sample at the fifth day (LW5) was the most similar to the natural fermentation sample at the seventh day (C7). The overall acceptance of LW5 was also the closest to that of C7 in sensory evaluation. In conclusion, mixed starter culture was shown to have a good effect on improving product quality and enhancing flavor with fermentation time shortened by 29%.