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

Inoculation with autochthonous yeast strains in Harbin dry sausages with partial substitution of NaCl by KCl: Bacterial community structure and flavour profiles

The effects of two autochthonous yeast strains (Pichia kudriavzevii and Debaryomyces hansenii) on the physicochemical characteristics, bacterial community structure, and flavour profile of the dry sausages with 40% substitution of NaCl by KCl were evaluated in this study. The results revealed that the inoculation of yeast strains increased the pH and yeast counts of low-sodium sausages. Higher contents of total esters, aldehydes, and ketones were detected in the inoculated sausages (P < 0.05). Based on the results of high-throughput sequencing, the inoculation of P. kudriavzevii decreased the abundance of Lactobacillus, Weissella, and Leuconostoc. However, the inoculation of D. hansenii increased the abundance of Lactobacillus, Weissella and Staphylococcus, which may help to inhibit the growth of pathogenic microorganisms in sausages. Electronic tongue analysis as well as sensory evaluation revealed that D. hansenii reduced bitter, astringent, and metallic tastes (P < 0.05). Overall, D. hansenii can be used as the prospective stater culture to compensate the flavour defects and improve the safety of the dry sausage with NaCl substitutes.

Coinoculation of autochthonous starter cultures: A strategy to improve the flavor characteristics and inhibit biogenic amines of Harbin dry sausage

The effects of separately coinoculating Lactiplantibacillus plantarum S8 (LP) with Staphylococcus carnosus L8 (LP + SC), Pichia kudriavzevii M6 (LP + PK), and S. carnosus L8 and P. kudriavzevii M6 (LP + SC + PK) on the flavor characteristics and biogenic amines (BAs) production in Harbin dry sausages were investigated. The coinoculated sausages exhibited higher free amino acids (FAAs) content than the noninoculated and LP sausages. Moreover, inoculated dry sausages exhibited lower BA contents (174.45, 239.43, 190.24, and 206.7 mg/kg for the LP, LP + SC, LP + PK, and LP + PK + SC sausages, respectively) than the noninoculated sausage (339.73 mg/kg). Meanwhile, the LP + PK and LP + SC + PK sausages had the highest contents of esters (996.70 μg/kg) and alcohols (603.46 μg/kg), respectively. A sensory evaluation demonstrated that the LP + SC + PK sausage had the highest fermented odor and the lowest fatty odor. Pearson correlation analysis revealed that FAAs were correlated with most key volatile compounds and BAs. This study provides new insights into flavor development and BA inhibition in dry sausages through coinoculation.

Dual Role of Yeasts and Filamentous Fungi in Fermented Sausages

This contribution aims to review the presence and the potential double role-positive or beneficial and negative or harmful-of fungi in fermented sausages as well as their use as starter cultures. Traditionally, studies have been focused on lactic acid bacteria; however, over the years, interest in the study of fungi has increased. The important contribution of yeasts and filamentous fungi to the quality and safety of fermented sausages has emerged from reviewing the literature regarding these fermented products. In conclusion, this review contributes to the existing literature by considering the double role of filamentous fungi and yeasts, the global fermented sausage market size, the role and use of starters, and the starters mainly present in the worldwide market, as well as the main factors to take into account to optimize production. Finally, some suggestions for future broadening of the sector are discussed.

Two Debaryomyces hansenii strains as starter cultures for improving the nutritional and sensory quality of dry-cured pork belly

Dry-cured meat products are gaining attention owing to their distinctive sensory characteristics and health benefits. In this study, two Debaryomyces hansenii strains were investigated for their potential as starter cultures for dry-cured pork belly products. After preliminary screening, these D. hansenii strains, namely, S20 and S26, both exhibiting with excellent aroma-producing capacity in a dry-cured meat model, were selected as single-strain starter cultures. For comparison, a non-inoculated control was also evaluated. In S20- and S26-inoculated pork belly, yeast dominated the microbiota and improved microbiological safety by suppressing Enterobacteriaceae growth. Compared with the non-inoculated control, the inoculated pork belly yielded higher hardness and redness (a*) values. Starter culture inoculation accelerated proteolysis in pork belly, improving the content of total free amino acids (TFFAs) and several essential free amino acids (Thr, Val, Met, Ile, Leu, and Phe) at the end of processing. Moreover, the inoculated samples exhibited higher levels of fat oxidation-derived aldehydes as well as esters, acids, alcohols and other compounds than the non-inoculated control at the end of the 95-day ripening period. Overall, these findings provide new insights into the application of D. hansenii isolated from dry-cured ham to dry-cured pork belly.

Effect of Yeast Inoculation on the Bacterial Community Structure in Reduced-Salt Harbin Dry Sausages: A Perspective of Fungi-Bacteria Interactions

Yeast strains are promising starters to compensate for the flavor deficiencies of reduced-salt dry sausages, but their influence on the bacterial community's structure has not yet been clarified. In this study, the effect of separately inoculating Pichia kudriavzevii MDJ1 (Pk) and Debaryomyces hansenii HRB3 (Dh) on the bacterial community structure in reduced-salt dry sausage was investigated. The results demonstrated that the inoculation of two yeast strains significantly reduced the pH, and enhanced the total acid content, lactic acid bacteria (LAB) counts, and total bacterial counts of reduced-salt sausages after a 12-day fermentation (p < 0.05). Furthermore, high-throughput sequencing results elucidated that the inoculation of yeast strains significantly affected the bacterial composition of the dry sausages. Especially, the relative abundance of bacteria at the firmicute level in the Pk and Dh treatments exhibited a significant increase of 83.22% and 82.19%, respectively, compared to the noninoculated reduced-salt dry sausage treatment (Cr). The relative abundance of Latilactobacillus, especially L. sakei (0.46%, 2.80%, 65.88%, and 33.41% for the traditional dry sausage (Ct), Cr, Pk, and Dh treatments, respectively), increased significantly in the reduced-salt sausages inoculated with two yeast strains. Our work demonstrates the dynamic changes in the bacterial composition of reduced-salt sausages inoculated with different yeast strains, which could provide the foundation for the in-depth study of fungi-bacteria interactions in fermented foods.

Insight into the Quality Development and Microbial Dynamics of Meat and Meat Products

Meat and meat products play a vital role in the daily diet due to their desirable texture, delicious flavor and nutritional value [...].

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.