Effect of nisin on the storage of sous vide processed Korean seasoned beef

Comparative analysis of the qualities of traditional and sous-vide marinated duck drumsticks

The sous-vide technique is increasingly used to improve the quality of poultry meat; the study aimed to compare the quality of traditional and sous-vide marinated (SVM) duck drumsticks by analyzing the sensory-related, nutritional, storage-related, and in vitro digestive-related quality of duck meat. The results showed that the sensory quality scores of color, odor, and appearance, L* and a* values of duck drumsticks in SVM group were significantly increased compared with the traditional marinated (TM) group (t-test, p < 0.05, the same below), and the b* values on the outside and inside of duck drumsticks were decreased by 22.47% and 38.04%, respectively. Compared with TM group, hardness, springiness, chewiness, adhesion, cohesion, and resilience of duck drumsticks in SVM group decreased by 43.32%, 29.52%, 65.08%, 62.35%, 20.23%, and 30.33%, respectively. The moisture content and total fat content of duck drumsticks in SVM group were significantly higher than those in TM group (p < 0.05), and the protein loss, total volatile basic nitrogen, and thiobarbituric acid reactive substances values were decreased by 61.4%, 25.86%, and 20.45%, respectively. The results of in vitro digestion experiments showed that the content of free sulfhydryl groups of duck drumsticks in SVM group was significantly increased (p < 0.05), and the contents of Schiff base and carbonyl groups were significantly decreased compared with the TM group (p < 0.05). In conclusion, the SVM technology could significantly improve the sensory-related qualities, reduce the loss of nutrients, and improve the storage-related qualities of duck drumsticks. This study provided theoretical reference for the high-value application of SVM technology in duck meat.

Cyclic peptide production from lactic acid bacteria (LAB) and their diverse applications

In recent years, cyclic peptides gave gained increasing attention owing to their pH tolerance, heat stability and resistance to enzymatic actions. The increasing outbreaks of antibiotic resistant pathogens and food spoilage have prompted researchers to search for new approaches to combat them. The increasing number of reports on novel cyclic peptides from lactic acid bacteria (LAB) is considered as a breakthrough due to their potential applications. Although an extensive investigation is required to understand the mechanism of action and range of applications, LAB cyclic peptides can be considered as potential substitutes for commercially available antibiotics and bio preservatives. This review summarizes the current updates of LAB cyclic peptides with emphasis on their structure, mode of action and applications. Recent trends in cyclic peptide applications are also discussed.

Polymeric Antimicrobial Food Packaging and Its Applications

Food corruption and spoilage caused by food-borne pathogens and microorganisms is a serious problem. As a result, the demand for antibacterial drugs in food packaging is growing. In this review, biodegradable and non-biodegradable materials for food packaging are discussed based on their properties. Most importantly, antibacterial agents are essential to inhibit the growth of bacteria in food. To keep food fresh and prolong the shelf life, different kinds of antibacterial agents were used. The composition and application of natural antibacterial agents and synthetic antibacterial agents are discussed. Compared with natural antibacterial agents, synthetic antibacterial agents have the advantages of low cost and high activity, but their toxicity is usually higher than that of natural antibacterial agents. Finally, future development of antimicrobial food packaging is proposed. It is an urgent problem for researchers to design and synthesize antibacterial drugs with high efficiency and low toxicity.

Bacteriocinogenic LAB Strains for Fermented Meat Preservation: Perspectives, Challenges, and Limitations

Over the last decades, much research has focused on lactic acid bacteria (LAB) bacteriocins because of their potential as biopreservatives and their action against the growth of spoilage microbes. Meat and fermented meat products are prone to microbial contamination, causing health risks, as well as economic losses in the meat industry. The use of bacteriocin-producing LAB starter or protective cultures is suitable for fermented meats. However, although bacteriocins can be produced during meat processing, their levels are usually much lower than those achieved during in vitro fermentations under optimal environmental conditions. Thus, the direct addition of a bacteriocin food additive would be desirable. Moreover, safety and technological characteristics of the bacteriocinogenic LAB must be considered before their widespread applications. This review describes the perspectives and challenges toward the complete disclosure of new bacteriocins as effective preservatives in the production of safe and "healthy" fermented meat products.

Kinetic modeling to study the quality of tambaqui (Colossoma macropomum) sous vide during storage at different temperatures

This study aimed to assess the changes in quality of tambaqui sous vide during refrigerated storage using degradation kinetics. Tambaqui sous vide was prepared and stored at three temperatures (1, 4, 10 °C). The microorganism counts and the physicochemical analyses were analyzed every three days. The results obtained were fitted to the Labuza models and by Arrhenius equation. The results of the microbiological and physicochemical analyses obtained better fits to the zero-order model. The Arrhenius equation better fit to the velocity constants of the zero-order model, which showed that the changes in the values of attributes are related to temperature. Higher Ea values were found for the microorganism counts than for the physicochemical parameters, which proves the greater dependency of microorganisms on variations in temperature. The assessment of changes in quality based on temperature allows the storage conditions to be optimized.

Nisin as a Food Preservative: Part 1: Physicochemical Properties, Antimicrobial Activity, and Main Uses

Nisin is a natural preservative for many food products. This bacteriocin is mainly used in dairy and meat products. Nisin inhibits pathogenic food borne bacteria such as Listeria monocytogenes and many other Gram-positive food spoilage microorganisms. Nisin can be used alone or in combination with other preservatives or also with several physical treatments. This paper reviews physicochemical and biological properties of nisin, the main factors affecting its antimicrobial effectiveness, and its food applications as an additive directly incorporated into food matrices.

Effect of sous vide processing on physicochemical, ultrastructural, microbial and sensory changes in vacuum packaged chicken sausages

The processing of sous vide chicken sausages was optimized under vacuum packaging condition and cooking at 100 ℃ for 30 min (SV30), 60 min (SV60) and 120 min (SV120) and compared with aerobically cooked control at 100 ℃ for 30 min. Sous vide processing of chicken sausages (SV30) produced higher ( p < 0.05) cooking yield, Hunterlab a* values and sensory attributes without affecting proximate composition and shear force values relative to control. The sodium dodecyl sulphate-polyacrylamide gel electrophoresis and scanning electron microscopy results revealed no significant changes in protein quality and emulsion ultra-structure due to SV30 processing relative to control sausages. Sous vide processing of chicken sausages enriched with rosemary diterpene phenols retained the freshness and quality up to 120 days during storage at 4 ± 1 ℃ relative to control sausages that were spoiled on 20th day. Lipid oxidation and microbial growth remained below the spoilage levels for all the SV-processed sausages throughout the storage and addition of rosemary diterpene mixture at 0.02% v/w reduced the microbial growth and improved ( p < 0.05) the sensory attributes. Our results demonstrate that sous vide processing minimizes lipid oxidation and microbial growth of chicken sausages with improved product quality and shelf-life at 4 ± 1 ℃.

Antimicrobial Effect of Nisin against Bacillus cereus in Beef Jerky during Storage

The microbial distribution of raw materials and beef jerky, and the effect of nisin on the growth of Bacillus cereus inoculated in beef jerky during storage, were studied. Five strains of pathogenic B. cereus were detected in beef jerky, and identified with 99.8% agreement using API CHB 50 kit. To evaluate the effect of nisin, beef jerky was inoculated with approximately 3 Log CFU/g of B. cereus mixed culture and nisin (100 IU/g and 500 IU/g). During the storage of beef jerky without nisin, the number of mesophilic bacteria and B. cereus increased unlikely for beef jerky with nisin. B. cereus started to grow after 3 d in 100 IU nisin/g treatment, and after 21 d in 500 IU nisin/g treatment. The results suggest that nisin could be an effective approach to extend the shelf-life, and improve the microbial safety of beef jerky, during storage.

Using numerical analysis to develop and evaluate the method of high temperature sous-vide to soften carrot texture in different-sized packages

The high-temperature sous-vide (HTSV) method was developed to prepare carrots with a soft texture at the appropriate degree of pasteurization. The effect of heating conditions, such as temperature and time, was investigated on various package sizes. Heating temperatures of 70, 80, and 90 °C and heating times of 10 and 20 min were used to evaluate the HTSV method. A 3-dimensional conduction model and numerical simulations were used to estimate the temperature distribution and the rate of heat transfer to samples with various geometries. Four different-sized packages were prepared by stacking carrot sticks of identical size (9.6 × 9.6 × 90 mm) in a row. The sizes of the packages used were as follows: (1) 9.6 × 86.4 × 90, (2) 19.2 × 163.2 × 90, (3) 28.8 × 86.4 × 90, and (4) 38.4 × 86.4 × 90 mm. Although only a moderate change in color (L*, a*, and b*) was observed following HTSV cooking, there was a significant decrease in carrot hardness. The geometry of the package and the heating conditions significantly influenced the degree of pasteurization and the final texture of the carrots. Numerical simulations successfully described the effect of geometry on samples at different heating conditions.

Inhibitory effects of nisin against Clostridium perfringens food poisoning and nonfood-borne isolates

The enterotoxigenic Clostridium perfringens type A is the causative agent of C. perfringens type A food poisoning (FP) and nonfood-borne (NFB) human gastrointestinal diseases. Due to its ability to form highly resistant endospores, it has become a great concern to the meat industry to produce meat free of C. perfringens. In this study, we evaluated the antimicrobial effect of nisin against C. perfringens FP and NFB isolates. No inhibitory effect of nisin was observed against germination of spores of both FP and NFB isolates in laboratory medium. However, nisin effectively arrested outgrowth of germinated spores of C. perfringens in rich medium. Interestingly, germinated spores of NFB isolates possessed higher resistance to nisin than that of FP isolates. Furthermore, nisin exhibited inhibitory effect against vegetative growth of both FP and NFB isolates in laboratory medium, with vegetative cells of NFB isolates showing higher resistance than that of FP isolates. However, the antimicrobial activity of nisin against C. perfringens was significantly decreased in a meat model system. In conclusion, although nisin showed inhibitory effect against spore outgrowth and vegetative cells of C. perfringens FP and NFB isolates in laboratory conditions, no such effect was observed against C. perfringens spores inoculated into a meat model system.