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The effects of combining a polyamide-alginate casing incorporated with nisin (100 ppm and 200 ppm) and ε-polylysine (500 ppm and 1000 ppm) nanoparticles and a mixed plant extract as ingredient in sausage formulation (500 ppm; composed of olive leaves (OLE), green tea (GTE) and stinging nettle extracts (SNE) in equal rates) were studied to improve the shelf life and safety of frankfurter-type sausage. The film characteristics and microbiological properties of sausage samples were evaluated. Sausage samples were packaged in polyethylene bags (vacuum condition) and analysed during 45 days of storage at 4 °C. Control sausages were also treated with 120 ppm sodium nitrite. Polyamide-alginate films containing 100 ppm nisin and 500 ε-PL nanoparticles had the highest ultimate tensile strength compared to other films. However, 100 ppm nisin and 500 ε-PL nanoparticles decreased water vapour permeability of films. The results also revealed that nisin nanoparticles had significantly (p < 0.05) low inhibitory effects against Escherichia coli, Staphylococcus aureus, molds and yeasts and total viable counts compared to control and ε-PL nanoparticles. Furthermore, 1000 ppm ε-PL nanoparticles displayed the highest antimicrobial activity. Based on the obtained results, the films containing ε-PL nanoparticle could be considered as a promising packaging for frankfurter-type sausages.

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DNA markers help detect the intraspecific genetic diversity of yeast strains. Eight ISSR (Inter Simple Sequence Repeats) primers were used to assess the intraspecific diversity of Saccharomyces cerevisiae (n = 96) from different populations (n = 3), evaluate the technological characteristics, and investigate trait-loci associations. The primers amplified 154 reproducible and scorable bands, of which 79.87% were polymorphic. The UPGMA (unweighted pair group method with arithmetic mean) dendrogram clustered 96 isolates into two main clusters, supported by STRUCTURE HARVESTER results (ΔK = 2). Analysis of molecular variance (AMOVA) indicated significant genetic differences between (15%) and within the populations (85%) (p < 0.001). Twenty-nine genetically distinct strains were selected for the technological characterization. Principal component analysis (PCA) revealed that five strains with high fermentation capacity, leavening activity, high growth index at 37 °C, and harsh growth conditions were technologically relevant. Trait-loci association analyses indicated that the highest correlation (r = 0.60) was recorded for the fermentation capacity on the 8th and 113th loci, amplified by ISSR-1 and ISSR-6 primers, respectively (p < 0.05). The strains yielding high performances and the associated loci amplified by ISSR markers possess a high potential to generate locus-specific primers to target the strains with high fermentation capacity.

This study aimed to evaluate the hemolytic activity and antibiotic susceptibility of enterococci isolated from Tulum cheese samples sold in Aksaray province. The isolates were identified as E. faecium (n = 30), E. faecalis (n = 25), and E. durans (n = 7) as a result of 16S rRNA gene sequencing. Three strains (E. faecalis ATC12, E. faecium ATC49, and E. faecium ATC54) exhibited ß-hemolytic activity, whereas others were non-hemolytic. Enterococci were found to have an intermediary or high resistance to nalidixic acid (%100), oxacillin (92%), and streptomycin (72.6%), respectively. E. faecalis strains had more resistant phenotypes to various clinically significant antibiotics than E. faecium and E. durans. Multi-drug resistance was found in 41.93% of the isolates. According to the results, Tulum cheese produced in Aksaray could be a potential vehicle for the transmission of antibiotic resistance via the food chain.

Beef is an animal food sensitive to deterioration with short shelf-life due to its rich nutrient content. Many studies concerned with the use of edible coating are carried out to increase the shelf life of beef. In this study, it was aimed to extend the shelf life of beef using chitosan. For this purpose, the bovine meat was coated with chitosan and stored at +4 ºC for 7 days. Total mesophilic aerobic bacteria, Stapylococcus aureus, Pseudomonas spp. counts and thiobarbituric acid values were analyzed. As a result, it was found that the chitosan coating reduced the TMAB, Pseudomonas spp. counts and TBARS values (P < 0.05) and inhibited all S. aureus up to day 5 of storage. According to the data obtained from this study, it has been concluded that chitosan can be used as a bio-preservative in the meat industry due to the antimicrobial and antioxidantive properties.