Effect of NaCl substitutes on the physical, microbial and sensory characteristics of Harbin dry sausage

Effect of curdlan on the physicochemical properties and microscopic morphology of spiced beef during cooking and freezing

This study aimed to establish the functional influence of curdlan (0 %, 1.0 %, 2.0 %, and 3.0 %) on the quality of spiced beef through monitoring changes in cooking yield, textural properties, pH, oxidative stability, and micromorphology during marination, cooking and freezing. The results showed significant enhancements (P < 0.05) of viscosity and absorption yield of the marinade solution as well as the freezing rate of spiced beef upon, increasing the curdlan concentration. At a 2.0 % curdlan addition level, spiced beef showed the maximum tenderness (shear force), increased springiness and elasticity. Meanwhile, the colorimetric values were improved and lipid oxidation (peroxide; malonaldehyde) was consistently reduced during storage up to 14 days, whereas 3.0 % curdlan on day 14 exacerbated oxidation. Scanning electron microscopy and confocal laser scanning microscopy imaging of beef samples treated with 1.0 % and 2.0 % curdlan showed a relatively even distribution of curdlan within muscle fiber bundles, contrasting to 3.0 % curdlan treatment where curdlan accumulated mostly in the gaps between muscle bundles and fibers. Additionally, low-field NMR analysis demonstrated that the inclusion of 2.0 % curdlan significantly increased the immobile water content (P23). In corroboration, sensory analysis indicated that spiced beef treated with 2.0 % curdlan had the highest appearance, juiciness, taste, and flavor scores, suggesting that muscle structural improvement by the curdlan inclusion, optimal at the 2.0 % level, played a principal role in the quality enhancements of marinaded spiced beef.

Characterization of emulsion co-encapsulated with probiotics and quercetin and its effect on the storage quality of Harbin red sausage

In this study, emulsions co-encapsulated with Bifidobacterium bifidum (B. bifidum) and quercetin (BQE) were prepared, and the encapsulation efficiency, antioxidant properties, storage stability, and digestive stability of emulsions containing different concentrations of quercetin were investigated. The results indicate that the prepared emulsion possesses excellent encapsulation efficiency and stability at quercetin concentration of 500 μg/mL. After in vitro digestion, the survival of B. bifidum improved, and the bioaccessibility of quercetin increased to 40.76 ± 1.10 % compared with that of free quercetin (25.16 ± 1.79 %). In addition, the emulsions were also combined with sodium alginate (SA) coating and applied to Harbin red sausage for storage. The results demonstrate that the coating exhibits certain antioxidant and aerobic bacterium-inhibiting effects. The moisture content of 1.5 %-BQE-SA coating was 42.48 % at 12 d, which was 4.14 % more than that of the control. The pH, color, and texture of Harbin red sausage were effectively preserved, successfully extending its shelf life by at least 3 days. Therefore, this study offers new insights into improving the stability of B. bifidum and quercetin, which can be employed to improve the quality of Harbin red sausage during storage.

Revealing the effects of compound curing agents on the microbial community and metabolites of Nuodeng ham based on high-throughput sequencing and metabolomics

To elucidate the effects of compound curing agent on the microbial community and metabolite composition of Nuodeng ham. The microbial community and small molecule metabolites of Nuodeng ham were analyzed using high-throughput sequencing and UPLC-QE-MS technology in this study. Staphylococcus, Acinetobacter, and Lactobacillus were found to be the dominant bacterial genera in Nuodeng ham. The compound curing agent promoted the formation of L-proline, phenylalanine, L-aspartic acid, and taurine. Through correlation analysis, it was found that Staphylococcus was positively correlated with L-proline and phenylalanine, while Acinetobacter was positively correlated with taurine. This study provides scientific theoretical support for compound curing agents, as well as insight into Nuodeng ham quality.

Techniques and Emerging Trends in Flavor and Taste Development in Meat

Flavor and taste are critical factors influencing consumer attraction for meat, shaping preferences and commercial demand. This review examines conventional and novel approaches to flavor and taste creation in the meat business, highlighting ways that improve sensory profiles and meet consumer demands. Conventional methods, such as aging and marination, are analyzed in conjunction with new technologies, including enzymatic treatment, fermentation, genetic treatments to alter texture and enhance umami. This study also emphasizes innovative methods to improve flavor of plant-based meat products, designed to meet the increasing demand for healthier, sustainable, and customizable meat products. The paper examines various methodologies and trends, offering a thorough grasp of flavor creation in the meat sector and highlighting the potential of creative approaches to transform meat flavor and taste profiles in response to evolving consumer and industry demands.

Effect of NaCl replacement by other salt mixtures on myofibrillar proteins: Underlining protein structure, gel formation, and chewing properties

The protein structure, gel changes, and chewing properties of low-sodium myofibrillar protein (MP) prepared by compound chloride salts (KCl/MgCl2, KCl/CaCl2, and KCl/MgCl2/CaCl2) and different substitution degrees (10%, 25%, and 40%) at same ionic strength (0.6 M) were investigated. The results revealed that the low-sodium MP gels containing CaCl2 manifested more liquid loss and less moisture content accompanied by obvious morphological shrinkage, while KCl/MgCl2 contributed to the gel juiciness. At high substitution degree of 40%, KCl/CaCl2 substitution rendered the gel with dense structure and highest strength, but worse water retention capacity. Using other compound chloride salts influenced the chewing efficiency, and CaCl2 substitution made the gel relatively hard to chew. The inhomogeneous structure accompanied by cluster blocks in KCl/CaCl2-substituted MP gel accelerated the overall fracture rate. During heating process, more proteins in CaCl2-substituted MP did not participate in gel formation, intervening the final gel properties. The chloride salt mixtures containing MgCl2, rather than CaCl2, avoided or alleviated the liquid loss and shrinkage of low-sodium MP gel within the substitution degree of 10%-40%, and substitution degree not exceeding 25% was more reasonable for the controlled qualities.

Improving the storage quality of Harbin red sausages by quaternized chitosan/sodium alginate coating curcumin nano-emulsion

In this study, the effect of sodium alginate and quaternized chitosan bis-polysaccharide-based shell transport curcumin nano-emulsions (Cur@QCS/SA) on the microbiological, physicochemical properties, quality characteristics of Harbin red sausage during storage is investigated. According to the microbiological results, the shelf life of Harbin red sausage is extended from 3 d to 6 d by adding 0.15% Cur@QCS/SA, and Bacillus is the most predominant bacterial before 6 d. Additionally, the physicochemical properties change significantly, the pH, weight loss (WL), water holding capacity (WHC), water activity (aw), L*, and a* of red sausage decrease gradually with the extension of storage time, as well as b*, lipid oxidation, proteolysis increase significantly (P < 0.05). Secondly, it is found that 0.15% treatment group can better maintain the quality characteristics of Harbin red sausage according to texture profile analysis (TPA), electronic nose (E-nose), and electronic tongue (E-tongue) (P < 0.05). This study provides a new way for nano-emulsions in food applications and a new option for the preservation of Harbin red sausage as well as other low-temperature meat products.

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.

Effects of umami substances as taste enhancers on salt reduction in meat products: A review

Sodium is one of the essential additives in meat processing, but excessive sodium intake may increase risk of hypertension and cardiovascular disease. However, reducing salt content while preserving its preservative effect, organoleptic properties, and technological characteristics poses challenges. In this review, the mechanism of salt reduction of umami substances was introduced from the perspective of gustation-taste interaction, and the effects of the addition of traditional umami substances (amino acids, nucleotides, organic acids(OAs)) and natural umami ingredients (mushrooms, seaweeds, tomatoes, soybeans, tea, grains) on the sensory properties of the meat with reduced-salt contents were summarized. In addition, the impacts of taste enhancers on eating quality (color, sensory, textural characteristics, and water-holding capacity (WHC)), and processing quality (lipid oxidation, pH) of meat products (MP) and their related mechanisms were also discussed. Among them, natural umami ingredients exhibit distinct advantages over traditional umami substances in terms of enhancing quality and nutritional value. On the basis of salt reduction, natural umami ingredients improve the flavor, texture, WHC and antioxidant capacity. This comprehensive review may provide the food industry with a theoretical foundation for mitigating salt consumption through the utilization of umami substances and natural ingredients.

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.

Oregano essential oil encapsulated in zein-pectin-chitosan nanoparticles to improve the storage quality of Harbin red sausage

In this study, the effect of oregano essential oil loaded in zein-pectin-chitosan (Zein-PC-CS-OEO) nanoparticles on the quality of Harbin red sausage during storage was examined. Zein-PC-CS-OEO nanoparticles exhibit the better encapsulation efficiency, antioxidant and antibacterial properties than these of other prepared nanoparticles, which were subsequently incorporated into Harbin red sausage with different concentrations. The physicochemical properties, bacterial community structure, and flavor characteristics of the Harbin red sausage were determined. Both thiobarbituric acid values and the growth of dominant spoilage bacteria in Harbin red sausage are inhibited by Zein-PC-CS-OEO nanoparticles, while the total aerobic bacteria count is reduced. These results indicate that the storage quality of Harbin red sausage is improved by Zein-PC-CS-OEO nanoparticles. It is worth noting that the shelf life of Harbin red sausage supplemented with 0.1 % Zein-PC-CS-OEO nanoparticles is extended to 9 d, and the flavor characteristics of which are better maintained. This study provides a new approach to extend the application of essential oil and improve the storage quality of Harbin red sausage.

Screening and evaluating microorganisms with broad-spectrum biogenic amine-degrading ability from naturally fermented dry sausage collected from Northeast China

This study aimed to screen autochthonous strains with broad-spectrum biogenic amine (BA) degradation ability from traditional dry sausages and to evaluate their BA-degrading ability in dry sausages. A total of 120 strains were isolated from dry sausages collected from various regions in Northeast China, and 35 of 120 isolates were identified as non-BA producing strains by the in vitro agar method. The random amplified polymorphic DNA polymerase chain reaction technique genotyped these 35 isolates into 18 biotypes. Moreover, high performance liquid chromatography (HPLC) quantification showed that six strains (Latilactobacillus sakei MDJ6; Lactiplantibacillus plantarum SH7; Weissella hellenica DQ9; Staphylococcus saprophyticus JX18 and SYS8; and Macrococcus caseolyticus SYS11) of the 18 biotypes exhibited broad-spectrum BA-degrading ability, all of which had various levels of amine oxidase activity with monoamine oxidase and diamine oxidase activities ranged of 6.60-619.04 and 26.32-352.81 U/mg protein, respectively. These six strains were subsequently inoculated into dry sausages and the results showed that they exhibited varying degrees of BA-degrading ability, of which strain Lat. sakei MDJ6 allowed to have less BA production on dry sausage with a final concentration of 61.33 mg/kg.

Hydrolysis of Beef Sarcoplasmic Protein by Dry-Aged Beef-Isolated Penicillium oxalicum and Its Associated Metabolic Pathways

Yanbian cattle have a unique meat flavor, and high-grade meat is in short supply. Therefore, in this study, we aimed to improve the added value of Yanbian cattle low-fat meat and provide a theoretical reference for the subsequent development of an excellent starter. Rump meat from Yanbian cattle was dry-aged and then screened for protease-producing fungi. Three protease-producing fungi (Yarrowia hollandica (D4 and D11), Penicillium oxalicum (D5), and Meesziomyces ophidis (D20)) were isolated from 40 d dry-aged beef samples, and their ability to hydrolyze proteins was determined using bovine sarcoplasmic protein extract. SDS-PAGE showed that the ability of Penicillium oxalicum (D5) to degrade proteins was stronger than the other two fungi. In addition, the volatile component content of sarcoplasmic proteins in the D5 group was the highest (45.47%) and comprised the most species (26 types). Metabolic pathway analysis of the fermentation broth showed that phenylalanine, tyrosine, and tryptophan biosynthesis was the most closely related metabolic pathway in sarcoplasmic protein fermentation by Penicillium oxalicum (D5). Dry-aged beef-isolated Penicillium oxalicum serves as a potential starter culture for the fermentation of meat products.

Bodybuilders and high-level meat consumers' behavior towards rabbit, beef, chicken, turkey, and lamb meat: A comparative review

In bodybuilders' diets, protein plays a crucial role in supporting muscle growth and repairing damaged muscle tissue. These individuals meet their protein needs by combining dietary sources with supplements. Animal-based proteins are often preferred over plant-based proteins because they are believed to better support muscle protein synthesis. This review explores the meat consumption patterns of bodybuilders and high-level meat consumers, focusing on rabbit, beef, chicken, turkey, and lamb. We describe and compare the types of meat bodybuilders commonly consume and provide an overview of protein supplements, including meat-based options, plant-based alternatives, and whey-based products. Our aim is to gain insight into the dietary preferences of bodybuilders and high-level meat consumers, considering their nutritional requirements and the potential effect on the meat industry. We conducted an extensive search across various databases, including Scopus, Web of Science, PubMed, and Google Scholar. We found that individual choices vary based on factors such as attitudes, trust, taste, texture, nutritional content, ethical considerations, and cultural influences. Nutritional factors, including protein content, amino acid profiles, and fat levels, significantly influence the preferences of bodybuilders and high-level meat consumers. However, it is crucial to maintain a balance by incorporating other essential nutrients such as carbohydrates, healthy fats, vitamins, and minerals to ensure a complete and balanced diet. The findings from this review can inform strategies and product development initiatives tailored to the needs of bodybuilders and discerning meat enthusiasts.

Impact of Micronized Salt in Reducing the Sodium Content in Fresh Sausages

This study aimed to investigate the incorporation of micronized salt (MS) to reduce sodium content in fresh sausages while preserving technological, chemical, textural, and sensory characteristics. Four treatments were prepared: control (C) with 2.0% regular salt; M2.0% with 2.0% micronized salt; M1.5% with 1.5% micronized salt; and M1.0% with 1.0% micronized salt, containing 1004, 1133, 860, and 525 mg of sodium/100 g of product, respectively. To characterize the samples, analyses of sodium content, cooking loss, relative myoglobin content, and instrumental color were carried out. The sensory analysis was performed using the Temporal-Check-All-That-Apply (TCATA) method. Half of the micronized salt treatment was mixed with the fat during the processing of the fresh sausages. It was possible to achieve a 50% reduction in sodium (M1.0%) in the fresh sausages without negative effects on most technological, chemical, and textural parameters, which did not differ from the control treatment (C). Conversely, "chewiness" decreased in M2.0% compared to the control (C) due to mixing micronized salt with the fat. The sodium reduction did not impact the temporal sensory profile and overall liking. Therefore, using micronized salt in fresh sausages reduces sodium content without affecting sensory traits and product stability.

Effects of Saccharomyces cerevisiae and Kluyveromyces marxianus on the Physicochemical, Microbial, and Flavor Changes of Sauce Meat during Storage

Saccharomyces cerevisiae (S. cerevisiae) and Kluyveromyces marxianus (K. marxianus) are often used as fermenters in yogurt and alcohol, and have been less studied within meat products. The yeasts were added to sauce meat, and the uninoculated group served as a control in this study to examine and compare the changing patterns of physicochemical and flavor characteristics of S. cerevisiae and K. marxianus on sauce meat during storage. The changes in moisture content, aw, pH, thiobarbituric acid reactive substances (TBARS), and other flavor characteristics were measured in sauce meat during the first, second, fourth, and sixth months after production. The following factors were examined: moisture content, aw, pH, TBARS, peroxide value (POV), acid value (AV), soluble protein (SP), free amino acid (FAA), and volatile flavoring compounds. With VIP > 1 and p < 0.05 as the screening conditions, the partial least squares model (PLS-DA) was used to assess the distinctive flavor components in the sausages. The findings demonstrated that the three groups' changes in sauce meat were comparable during the first two months of storage but differed significantly between the 4th and 6th months. The moisture content, water activity, and pH of the sauce meat decreased gradually with the storage time; TBARS, AV, and FAA increased significantly; SP decreased significantly from 2.61 to 1.72, while POV increased to 0.03 and then decreased to 0.02. The POV and TBARS values of the yeast-infected meat were substantially lower than those of the control group, and the POV and TBARS values of the meat inoculated with S. cerevisiae were particularly decreased (p < 0.05). The POV and TBARS values of SC (S. cerevisiae group) decreased by 49.09% and 40.15%, respectively, compared to CK (the control group) at the time of storage until June. The experimental group (KM: K. marxianus group) significantly increased the SP and FAA values of the sauce meat (p < 0.05) by 32.4% and 29.84% compared to the CK group, respectively. Esters and olefins as well as alcohols and esters were much greater in meat that had been supplemented with S. cerevisiae and K. marxianus than in meat from the control group. In conclusion, inoculating sauce meat with S. cerevisiae can significantly enhance the quality and flavor of sauce meat while it is being stored.

Effects of ultrasound-assisted curing on the quality and microstructure of low-sodium beef jerky

The effects of ultrasonic brine on the physicochemical properties, sensory quality and microstructure of low-sodium beef jerkies were investigated. Compared with control jerky brined in 1.5% NaCl solution, both of the direct reduction and partial replacement of 50% NaCl by KCl decreased the sodium content. Ultrasonic treatment resulted in sharp reduction in shear force. KCl substitution together with ultrasonic treatment caused the highest yield, a* value and water content, and the water activity of all groups were below 0.85. Only the direct reduction of NaCl had negative effects on the sensory quality. KCl substitution combined with ultrasonic treatment was the most suitable for producing low-sodium beef jerkies with high quality, possibly because the mixed salt had equal total salt content to control. Meanwhile, the cavitation and mechanical effects of ultrasound may unfold protein structure, increase myofibrillar fragmentation index and break the muscle fiber, thus improving the quality of beef jerky.

The Effect of Plasma-Activated Water Combined with Rosemary Extract (Rosmarinus officinalis L.) on the Physicochemical Properties of Frankfurter Sausage during Storage

This study investigated the impact of plasma-activated water (PAW) and rosemary extract on the bacterial inactivation and quality attributes of Frankfurter sausages during a 6-day storage period. The antibacterial activity, total phenol content (TPC), and total flavonoid content (TFC) of the rosemary extract were evaluated. The TPC of the rosemary extract was 89.45 mg gallic acid/g dry weight, while the TFC was 102.3 mg QE/g dry weight. Even at low concentrations, the rosemary extract effectively inhibited the growth of all the tested pathogens using the Well Diffusion Agar method (WDA). The sausages were treated with different concentrations of PAW and rosemary extract and stored for 1 and 6 days. Sample B (100% rosemary extract + PAW treatment) showed the greatest reduction in microbial load and was selected for further analysis. Throughout the storage period, Sample B exhibited no significant changes in pH, moisture content, textural parameters, or sensory evaluation compared to the control group. However, the hardness and color parameters (L*, a*) of Sample B decreased, while the TBARS value increased after 6 days of storage. The combination of PAW and rosemary extract, particularly Sample B, effectively inhibited bacterial growth in the Frankfurter sausages without compromising most quality attributes. Some changes in hardness, color, and lipid oxidation were observed over the extended storage period.

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.

Effects of replacement partial sodium chloride on characteristic flavor substances of bacon during storage based on GC×GC-MS and non-targeted metabolomics analyses

Comprehensive 2D gas chromatography-mass spectrometry (GC × GC-MS) and non-targeted metabolomics were employed to investigate the differences in key volatile flavor substances between bacon salted with alternative salt and traditional bacon during storage. The GC × GC-MS analysis revealed that among 146 volatile compounds in both types of bacon, alcohol, aldehydes, ketones, phenols, and alkenes were the most abundant. Additionally, non-targeted metabolomics indicated that the changes in amino acids and the oxidation degradation of lipids could be the main reasons for the flavor differences among the two kinds of bacon. Furthermore, the acceptability scores of both bacon types showed a general upward trend as the storage time increased, indicating that the metabolic of substances occurring during bacon storage significantly impact its overall quality. By partially substituting sodium chloride with 22% potassium chloride and 11% calcium ascorbate, coupled with appropriate storage conditions, the quality of bacon can be improved.

Flavour Profile of Traditional Dry Sausage Prepared with Partial Substitution of NaCl with KCl

The effects of partial substitution of NaCl with 0%, 20%, 30% and 40% KCl on the physical characteristics, bacterial community and flavour profile of traditional dry sausage were investigated in this study. With the increase in KCl substitution ratio, the moisture content, astringency, bitterness and umami increased significantly, and the saltiness gradually decreased (p < 0.05). The high-throughput sequencing results showed that the dry sausages with KCl substitution had relatively high abundances of Staphylococcus. For volatile compounds, increasing the KCl substitution ratio reduced the formation of aldehydes, ketones and some alcohols, but promoted the formation of acids and esters (p < 0.05). Sensory evaluation and partial least square regression analysis showed that the dry sausages with 20% and 30% KCl were similar in overall physical and microbial properties, flavour profiles and sensory attributes, and the sausages with 40% KCl were characterized by taste defects. Overall, partial substitution of NaCl with 30% KCl could ensure the acceptable flavour and sensory attributes of dry sausages.

Effects of sorbitol-mediated curing on the physicochemical properties and bacterial community composition of loin ham during fermentation and ripening stages

In this study, the impacts of loin ham with sorbitol-mediated curing on its physicochemical properties and bacterial community composition during fermentation and ripening were investigated. The salt content, pH, and water activity (a_w) were lower in the sorbitol group than in the control group throughout the fermentation and ripening stages (P < 0.05). In addition, the L* values were higher in the sorbitol group (P < 0.05). Additionally, microbial diversity diminished in all groups as the fermentation and ripening process proceeded, with Lactobacillus turning into the dominant genus in the control group and Staphylococcus and Lactobacillus becoming dominant in the sorbitol group. Pearson's correlation analysis confirmed that the physicochemical properties have been significantly correlated with the bacterial community. In conclusion, sorbitol-mediated curing not only facilitates salt reduction while prolonging the storage period of loin ham, but also improves the distribution of bacterial community in loin ham and enhances its quality.

Insights into the flavor perception and enhancement of sodium-reduced fermented foods: A review

Salt (sodium chloride, NaCl) is a vital ingredient in fermented foods, which affects their safety, texture, and flavor characteristics. Recently, the demand for reduced-sodium fermented foods has increased, as consumers have become more health-conscious. However, reducing sodium content in fermented foods may negatively affect flavor perception, which is a critical quality attribute of fermented foods for both the food industry and consumers. This review summarizes the role of salt in the human body and foods and its role in the flavor perception of fermented foods. Current sodium reduction strategies used in the food industry mainly include the direct stealth reduction of NaCl, substituting NaCl with other chloride salts, and structure modification of NaCl. The odor-induced saltiness enhancement, application of starter cultures, flavor enhancers, and non-thermal processing technology are potential strategies for flavor compensation of sodium-reduced fermented foods. However, reducing sodium in fermented food is challenging due to its specific role in flavor perception (e.g., promoting saltiness and volatile compound release from food matrices, inhibiting bitterness, and changing microflora structure). Therefore, multiple challenges must be addressed in order to improve the flavor of low-sodium fermented foods. Future studies should thus focus on the combination of several strategies to compensate for the deficiencies in flavor resulting from sodium reduction.

Physicochemical property, bacterial diversity, and volatile profile during ripening of naturally fermented dry mutton sausage produced from Jianzhou big-eared goat

Physicochemical properties, bacterial communities, and volatile compounds of mutton sausage produced from Jianzhou Big-Eared goat meat during natural ripening were investigated. Firmicutes and Bacteroidetes accounted for over 66% of all operational taxonomic units (OTUs) throughout the whole process, with Lachnospiraceae_NK4A136_group and Staphylococcus as the predominant genus during the early and later ripening periods, respectively. The evolution of microbial composition became less rich and diverse. The uncultured bacterium, the Lachnospiraceae_NK4A136_group, and Staphylococcus were marker bacteria on days 0, 7, and 26, respectively, with none on day 16. The bacteria distribution seemed to influence the volatile profile of mutton sausage throughout processing, with the bacterial composition on day 0 and day 7 clustered separately from day 16 and day 26, and the same pattern for the volatile profile. Meanwhile, the concentration of total volatile fraction significantly increased, and the majority of the volatile compounds were generated during late ripening. Non-anal, hexanal, decanal, heptanal, dodecyl aldehyde, benzaldehyde, 3-methylbutanal, γ-dodecalactone, 2-pentylfuran, and 1-octen-3-ol were key volatile compounds, contributing to the overall mutton sausage flavors. Based on Spearman’s correlation analysis, Staphylococcus as well as Psychrobacter were positively correlated with the production of the key volatile compounds, and other bacteria such as Lachnospiraceae_NK4A136_group, Bacteroides, Lactobacillus, Prevotella_1, Odoribacter, and so on were associated with the production of most alcohols and esters.

Bacterial community diversity and its potential contributions to the flavor components of traditional smoked horsemeat sausage in Xinjiang, China

Smoked horsemeat sausage is a famous fermented traditional food in Xinjiang, China. However, the microbial diversity and its potential contributions to the flavor components of smoked horsemeat sausage are unclear. In this study, the microbial community and flavor components of smoked horsemeat sausage from six regions of Xinjiang were measured by using amplicon sequencing and headspace solid-phase microextraction combined with gas chromatography–mass spectrometry (HS-SPME-GC–MS) technology, respectively. Relations among microbial communities, flavor components and environmental factors were subsequently predicted based on redundancy analysis (RDA) and Monte Carlo permutation tests. Although smoked horsemeat sausage samples from different regions possessed distinct microbial communities, lactic acid bacteria (LAB) were identified as the dominant consortium in smoked horsemeat sausage. Lactobacillus, Vagococcus, Lactococcus, and Carnobacterium were detected at high abundance in different sausages. The moisture content, nitrite content, and pH of the sausage might be important factors influencing the dominant bacterial community, according to the RDA. Among the dominant consortia, the eight core bacterial genera showed considerable correlations with the formation of sixteen volatile compounds in smoked horsemeat sausage based on multivariate statistical analysis. For example, the levels of Leuconostoc and Lactobacillus were positively correlated with those of 1-hexadecanol, hexyl acetate, 2-methyl-phenol, 1-pentanol, d-limonene, and 2-heptanone, and the levels of Leuconostoc, Lactobacillus, and Weissella were negatively correlated with those of 1-octanol, acetic acid, octanal, heptanal, and 1-hexanol. This study will provide a theoretical basis for understanding the microbial metabolic modes of Xinjiang smoked horsemeat sausages.

Evaluation of Hesperidin on Sausages Stuffed in a New Modified Casing during Long-Term Storage—A Preliminary Study

The effects of hesperidin and different casings on pH, moisture content, water-holding capacity, and total viable count (TVC) of sausages stored for 171 days were evaluated by principal component analysis (PCA) and discriminant analysis (DA). Sausages stuffed in a modified casing with treatment B (soy lecithin concentration: 1:30, soy oil concentration: 2.5%, lactic acid concentration: 21 mL/kg NaCl [solid], treated time: 90 min) had a significantly lower pH value (6.89 ± 0.01) at d 31 but higher (6.55 ± 0.03) than that of control casings at d 171 (p < 0.05). Hesperidin plays an important role in antimicrobial property that renders the sausages with modified casing by treatment A (soy lecithin concentration: 1:27.5, soy oil concentration: 1.25%, lactic acid concentration: 19.5 mL/kg NaCl [solid], treated time: 75 min) stable (p > 0.05), with the final TVC of 5.03 ± 0.10 log cfu/g. According to the PCA results, water-holding capacity has a positive correlation to pH. Moisture content was the best discriminator for differentiating sausages with control and modified casings, whilst pH was able to discriminate sausages stored after 138 days from other days.

Evaluation and monitoring of the quality of sausages by different analytical techniques over the last five years

Sausages are among the most vulnerable and perishable products, although those products are an important source of essential nutrients for human organisms. The evaluation of the quality of sausages becomes more and more required by consumers, producers, and authorities to thwarter falsification. Numerous analytical techniques including chemical, sensory, chromatography, and so on, are employed for the determination of the quality and authenticity of sausages. These methods are expensive and time consuming, and are often sensitive to significant sources of variation. Therefore, rapid analytical techniques such as fluorescence spectroscopy, near infrared (NIR), mid infrared (MIR), nuclear magnetic resonance (NMR), among others were considered helpful tools in this domain. This review will identify current gaps related to different analytical techniques in assessing and monitoring the quality of sausages and discuss the drawbacks of existing analytical methods regarding the quality and authenticity of sausages from 2015 up to now.

Flavour Compensation Role of Yeast Strains in Reduced-Salt Dry Sausages: Taste and Odour Profiles

The effects of different yeast strains including Pichia kudriavzevii, Torulaspora delbrueckii, and Debaryomyces hansenii on the taste and odour profiles of reduced-salt dry sausages were explored. Inoculation of P. kudriavzevii and D. hansenii compensated for the lack of saltiness and umami tastes of reduced-salt sausages. Furthermore, inoculation of P. kudriavzevii and T. delbrueckii resulted in an odour profile in the reduced-salt dry sausages that was similar to traditional dry sausages. According to the volatile analysis, the contents of certain alcohols, acids, esters and terpenes were higher in the inoculated sausages. Finally, the sensory evaluation indicated that the inoculation of P. kudriavzevii and D. hansenii contributed positively to the aroma and saltiness of reduced-salt dry sausages. In conclusion, P. kudriavzevii and D. hansenii can be employed as effective starter cultures to compensate for the flavour deficiencies of reduced-salt dry sausages.

Influence of Partial Replacements of NaCl by KCl on Quality Characteristics and the Heterocyclic Aromatic Amine Contents of Bacon

The influence of partial replacements of NaCl by KCl (0, 10, 20, and 30%) on the heterocyclic aromatic amine (HAAs) contents and quality characteristics of bacon were investigated. The Na⁺ content, moisture, a_w, pH, L* value, and sensory saltiness decreased and K⁺ content, a* value, and sensory bitterness increased significantly with increased substituting rates of NaCl by KCl (p < 0.05). There were no significant differences between the control and KCl substitution samples for the b* value, redness, and sensory off-odor (p > 0.05). The creatine content was not affected by the different KCl-substituting rates during the marinating process (p > 0.05), but it diminished in the smoking and frying processes (p < 0.05). The increase in the KCl-substituting rates increased the total heterocyclic aromatic amine (HAA) contents in fried bacon (p < 0.05). Moreover, the nonpolar HAA content in bacon was higher than the polar HAA content (p < 0.05). In summary, the partial replacement of NaCl by KCl increased the total HAA content and led to changes in bacon quality.

Recent advances in the development of healthier meat products

Meat products are an excellent source of high biological value proteins, in addition to the high content of minerals, vitamins, and bioactive compounds. However, meat products contain compounds that can cause a variety of adverse health effects and pose a serious health threat to humans. In this sense, this chapter will address recent strategies to assist in the development of healthier meat products. The main advances about the reduction of sodium and animal fat in meat products will be presented. In addition, strategies to make the lipid profile of meat products more nutritionally advantageous for human health will also be discussed. Finally, the reduction of substances of safety concern in meat products will be addressed, including phosphates, nitrites, polycyclic aromatic hydrocarbons, heterocyclic aromatic amines, as well as products from lipid and protein oxidation.

Characterisation of changes in physicochemical, textural and microbiological properties of Njeguška sausage during ripening

The purpose of this paper was to investigate effect of ripening time on physicochemical, textural and microbiological properties of Njeguška (dry fermented sausage) during ripening and to conduct sensory and free fatty acid characterization of final product. Ripening time significantly (p < 0.05) affected all physicochemical parameters. Moisture content dropped below national regulation limit (35%) after 12 days, which indicates that production process could be shortened for 4 days. Total weight loss was 36.34%. Due to its final pH (5.54), Njeguška can be classified as low-acid sausage which microbial safety mostly relies on its low water activity (< 0.80). Final TBARS value was 0.27 mg MDA/kg. Levels of tyramine (36.9 mg/kg) and putrescine (16.7 mg/kg) were the highest among all biogenic amines while levels of remaining amines were under 5 mg/kg. Hardness, gumminess and chewiness significantly (p < 0.05) increased during processing to reach final values of 65.59 N, 33.60 N and 19.12 N, respectively. Ripening time had significant effect on color (L^*, a^* and b^*) of surface, meat and fat parts which were all measured separately. Total viable count, lactic acid bacteria and Micrococcaceae counts increased from 5.11 log cfu/g, 3.90 log cfu/g and 2.41 log cfu/g to 7.96 log cfu/g, 7.04 log cfu/g and 4.86 log cfu/g, respectively. Results of sensory characterization showed high scores for smoky flavor, consistency, fattiness, fat/meat cohesiveness and saltiness while lactic acid odor and overall acidity were rated low.

Effect of Salt Content Reduction on Food Processing Technology

Higher salt intake is associated with the risk of cardiovascular and kidney diseases, hypertension and gastric cancer. Salt intake reduction represents an effective way to improve people’s health, either by the right choice of food or by a reduction of added salt. Salt substitutes are often used and also herb homogenates are treated by high pressure technology. Salt reduction significantly influences the shelf life, texture, pH, taste, and aroma of cheese. The composition of emulsifying salts or starter cultures must be modified to enact changes in microbial diversity, protease activity and the ripening process. The texture becomes softer and aroma atypical. In bakery products, a salt reduction of only 20–30% is acceptable. Water absorption, dough development, length and intensity of kneading and stability of dough are changed. Gluten development and its viscoelastic properties are affected. The salt reduction promotes yeast growth and CO₂ production. Specific volume and crust colour intensity decreased, and the crumb porosity changed. In meat products, salt provides flavour, texture, and shelf life, and water activity increases. In this case, myofibrillar proteins’ solubility, water binding activity and colour intensity changes were found. The composition of curing nitrite salt mixtures and starter cultures must be modified.

Microbial Diversity and Non-volatile Metabolites Profile of Low-Temperature Sausage Stored at Room Temperature

Sausage is a highly perishable food with unique spoilage characteristics primarily because of its specific means of production. The quality of sausage during storage is determined by its microbial and metabolite changes. This study developed a preservative-free low-temperature sausage model and coated it with natural casing. We characterized the microbiota and non-volatile metabolites in the sausage after storage at 20°C for up to 12 days. Bacillus velezensis was the most prevalent species observed after 4 days. Lipids and lipid-like molecules, organoheterocyclic compounds, and organic acids and their derivatives were the primary non-volatile metabolites. The key non-volatile compounds were mainly involved in protein catabolism and β-lipid oxidation. These findings provide useful information for the optimization of sausage storage conditions.

Changes in chilled beef packaged in starch film containing sea buckthorn pomace extract and quality changes in the film during super-chilled storage

This study aimed to evaluate the effects of super-chilled storage (-1.3 °C) combined with starch film packaging containing different contents of sea buckthorn pomace extract (SSF, 0, 1, 2, and 3%, w/w) on the quality of chilled beef. The release kinetics, microstructure, and mechanical properties of the film were also measured to investigate its suitability for super-chilled storage. The results of the meat quality assessment showed that the L*, a*, and sensory evaluation values of the SSF-3% samples were significantly higher (P < 0.05), and the pH, b*, thiobarbituric acid reactive substance (TBARS), total volatile basic nitrogen (TVB-N), and total viable count (TCA) were significantly lower (P < 0.05) than the SSF-0%. The release of SBP from the SSF film was controlled by diffusion. Furthermore, SSF-3% was found to have a compact microstructure and good mechanical properties at the end of the super-chilled storage. The results demonstrated that SSF is an effective packaging material for beef at super-chilling temperatures.

Composite Gel Fabricated with Konjac Glucomannan and Carrageenan Could Be Used as a Cube Fat Substitute to Partially Replace Pork Fat in Harbin Dry Sausages

The effect of the partial replacement of pork back-fat with a cube fat substitute (CFS) fabricated from konjac glucomannan and carrageenan on the physicochemical and sensory characteristics of Harbin dry sausages during 7 days of fermentation was investigated. There were the following five treatments: control (100% back-fat), FS1 (80% back-fat, 20% CFS), FS2 (60% back-fat, 40% CFS), FS3 (40% back-fat, 60% CFS) and FS4 (20% back-fat, 80% CFS). The results showed no significant differences (p > 0.05) in the physicochemical and sensory characteristics among the control, FS1 and FS2 treatments. However, higher replacement levels (60% and 80%) rendered higher degrees of change in the characteristics of the sausages, lowering the moisture content and a_w and increasing the pH, hardness, chewiness and atypical appearance at the end of fermentation. Moreover, electronic nose analysis and hierarchical cluster analysis demonstrated that the FS3 and FS4 treatments destroyed the characteristic quality of the sausage. Overall, our results indicated that, to ensure the traditional characteristics of Harbin dry sausages, the upper limit of the fat replacement level with CFS should be set at 40%.

Cyprus Sausages' Bacterial Community Identification Through Metataxonomic Sequencing: Evaluation of the Impact of Different DNA Extraction Protocols on the Sausages' Microbial Diversity Representation

Cyprus traditional sausages from the Troodos mountainous region of Pitsilia gained the protected geographical indication (PGI) designation from the European Committee (EU 2020/C 203/06). Still, we lack authentication protocols for the distinction of “Pitsilia” from industrially produced Cyprus sausages. Microbial activity is an essential contributor to traditional sausages’ sensorial characteristics, but whether the microbial patterns might be associated with the area of production is unclear. In the present research, we applied high-throughput sequencing (HTS) to provide a linkage between the area of production and Cyprus sausages’ bacterial diversity. To strengthen our findings, we used three different DNA extraction commercial kits: (i) the DNeasy PowerFood Microbial Kit (QIAGEN); (ii) the NucleoSpin Food Kit (MACHEREY-NAGEL); and (iii) the blackPREP Food DNA I Kit (Analytik Jena), in which we applied three different microbial cell wall lysis modifications. The modifications included heat treatment, bead beating, and enzymatic treatment. Results regarding metagenomic sequencing were evaluated in terms of number of reads, alpha diversity indexes, and taxonomic composition. The efficacy of each method of DNA isolation was assessed quantitatively based on the extracted DNA yield and the obtained copy number of (a) the 16S rRNA gene, (b) the internal transcribed spacer (ITS) region, and (c) three Gram-positive bacteria that belong to the genera Latilactobacillus (formerly Lactobacillus), Bacillus, and Enterococcus via absolute quantification using qPCR. Compared with some examined industrial sausages, Pitsilia sausages had significantly higher bacterial alpha diversity (Shannon and Simpson indexes). Principal coordinates analysis separated the total bacterial community composition (beta diversity) of the three Pitsilia sausages from the industrial sausages, with the exception of one industrial sausage produced in Pitsilia, according to the manufacturer. Although the eight sausages shared the abundant bacterial taxa based on 16S rDNA HTS, we observed differences associated with bacterial diversity representation and specific genera. The findings indicate that the microbial communities may be used as an additional tool for identifying of the authenticity of Cypriot sausages.