Effect of inoculation of starter on physicochemical properties and texture characteristics of fermented beef jerky

Effect of Zanthoxylum bungeanum extract on the quality and cathepsin L activity of Niuganba

Niuganba (NGB) is a traditional fermented beef product. Protease activity typically significantly affects the quality of NGB. Some natural food extracts may markedly influence NGB's protease activity and performance. This study aims to investigate the effect of Zanthoxylum bungeanum extract (ZBE) on the quality and cathepsin L activity of NGB. Following ZBE treatment, the myofibril fragmentation index (MFI), the content of TCA-soluble peptides, surface hydrophobicity, disulfide bond content, and cathepsin L activity of NGB significantly decrease. The content of free thiol groups and β-sheet significantly increases. Scanning electron microscopy (SEM) reveals that the arrangement of muscle fibers in the cross-section of NGB is more compact after ZBE treatment. The research results indicate that ZBE effectively inhibits cathepsin L activity, alleviates the degradation of myofibrillar proteins, improves the physicochemical characteristics of NGB, and enhances its structural stability.

The Effect of Lactiplantibacillus plantarum x3-2b Bacterial Powder on the Physicochemical Quality and Biogenic Amines of Fermented Lamb Jerky

In this study, a protective agent was added to prepare a high-activity Lactiplantibacillus plantarum x3-2b bacterial powder as a fermentation agent and explore its effect on the physicochemical quality, biogenic amines, and flavor of fermented lamb jerky. A composite protective agent, composed of 15% skim milk powder and 10% trehalose, was used, and bacterial mud was mixed with the protective agent at a 1:1.2 mass ratio. The resulting freeze-dried bacterial powder achieved a viable count of 5.1 lg CFU/g with a lyophilization survival rate of 87.58%. Scanning electron microscopy revealed enhanced cell coverage by the composite protective agent, maintaining the cell membrane's integrity. Inoculation with x3-2b bacterial powder increased the pH and the reduction in aw, enhanced the appearance and texture of fermented lamb jerky, increased the variety and quantity of flavor compounds, and reduced the accumulation of biogenic amines (phenethylamine, histamine, and putrescine). This research provides a theoretical basis for improving and regulating the quality of lamb jerky and establishes a foundation for the development of bacterial powder for the commercial fermentation of meat products.

The combination of high-throughput sequencing and LC-MS/MS reveals the mechanism of Staphylococcus inoculation on bacterial community succession and taste development during the processing of dry-cured bacon

BACKGROUND

To understand the mechanism of co-inoculation of Staphylococcus vitulinus and Staphylococcus xylosus (SX&SV) on taste quality of dry-cured bacon, physicochemical parameters, microbial community, metabolite compositions and taste attributes were investigated during the processing of dry-cured bacon with Staphylococcus inoculation. The potential correlation between core bacteria and metabolites was evaluated, and the metabolic pathway of key metabolites was further explored.

RESULTS

The values of pH, water activity and adhesiveness were significantly lower in SX&SV, and more than 2.56- and 2.15-fold higher values in richness and overall acceptance were found in SX&SV bacon than in CK bacon. The overwhelming advantage of Staphylococcus was confirmed in SX&SV by high-throughput sequencing. Sixty-six metabolites were identified by liquid chromatography-tandem mass spectrometry, and oligopeptides, amino acid derivatives and organic acids were the key components. Pearson correlation demonstrated that the accumulation of oligopeptides, amino acid derivatives and organic acids were positively correlated with high abundance of Staphylococcus. The pathways of purine metabolism, glutathione metabolism and glutamate metabolism were mainly involved in developing the taste quality of SX&SV.

CONCLUSION

The co-inoculation of Staphylococcus vitulinus and Staphylococcus xylosus enhanced the taste attributes of dry-cured bacon. The present study provides the theoretical reference with respect to regulating the taste quality of fermented meat products by starter cultures of Staphylococcus during manufacture. © 2023 Society of Chemical Industry.

The potentials and challenges of using fermentation to improve the sensory quality of plant-based meat analogs

Despite the advancements made in improving the quality of plant-based meat substitutes, more work needs to be done to match the texture, appearance, and flavor of real meat. This review aims to cover the sensory quality constraints of plant-based meat analogs and provides fermentation as a sustainable approach to push these boundaries. Plant-based meat analogs have been observed to have weak and soft textural quality, poor mouth feel, an unstable color, and unpleasant and beany flavors in some cases, necessitating the search for efficient novel technologies. A wide range of microorganisms, including bacteria such as Lactobacillus acidophilus and Lactiplantibacillus plantarum, as well as fungi like Fusarium venenatum and Neurospora intermedia, have improved the product texture to mimic fibrous meat structures. Additionally, the chewiness and hardness of the resulting meat analogs have been further improved through the use of Bacillus subtilis. However, excessive fermentation may result in a decrease in the final product's firmness and produce a slimy texture. Similarly, several microbial metabolites can mimic the color and flavor of meat, with some concerns. It appears that fermentation is a promising approach to modulating the sensory profiles of plant-derived meat ingredients without adverse consequences. In addition, the technology of starter cultures can be optimized and introduced as a new strategy to enhance the organoleptic properties of plant-based meat while still meeting the needs of an expanding and sustainable economy.

Significance of Fermentation in Plant-Based Meat Analogs: A Critical Review of Nutrition, and Safety-Related Aspects

Plant-based meat analogs have been shown to cause less harm for both human health and the environment compared to real meat, especially processed meat. However, the intense pressure to enhance the sensory qualities of plant-based meat alternatives has caused their nutritional and safety aspects to be overlooked. This paper reviews our current understanding of the nutrition and safety behind plant-based meat alternatives, proposing fermentation as a potential way of overcoming limitations in these aspects. Plant protein blends, fortification, and preservatives have been the main methods for enhancing the nutritional content and stability of plant-based meat alternatives, but concerns that include safety, nutrient deficiencies, low digestibility, high allergenicity, and high costs have been raised in their use. Fermentation with microorganisms such as Bacillus subtilis, Lactiplantibacillus plantarum, Neurospora intermedia, and Rhizopus oryzae improves digestibility and reduces allergenicity and antinutritive factors more effectively. At the same time, microbial metabolites can boost the final product's safety, nutrition, and sensory quality, although some concerns regarding their toxicity remain. Designing a single starter culture or microbial consortium for plant-based meat alternatives can be a novel solution for advancing the health benefits of the final product while still fulfilling the demands of an expanding and sustainable economy.

Effects of Process Parameters on the Quality of Suantang Beef

Suantang beef is a traditional delicious Chinese food cooked in Suantang (ST, a sour soup fermented by microorganisms). However, the impact of ST on beef quality is unclear, and the process of ST beef lacks unified technical standards. In the presented study, we found that the additional amount of salt, cooking time, meat thickness, and beef-ST ratio significantly affect the quality of ST beef. After optimization, it was found that when salt addition was 1%, cooking time was 3 min, meat thickness was 2 cm, and beef-ST ratio was 40%, the color determined by colorimeter, texture determined by texture analyzer, and sensory scores of beef cooked by ST were improved compared with boiled beef. ST decreased the pH value and cathepsin L activity of beef, increased the content of organic acid, and changed the protein composition of beef. ST made the beef have higher hardness, and have better chewiness and cohesion. At the same time, ST reduced the disagreeable odors of beef and improved beef flavor. In addition, 88 volatile compounds were detected in ST beef by HS-SPME/GC-MS. According to odor, threshold, and odor activity value (OAV), 24 critical aroma-active compounds were confirmed in ST beef. This study provides a basis for the potential industrialized production of ST beef.