This study determined the proximate composition, energy value, amino acid profile, and protein quality of the muscle tissue of four food fish species. The fish analyzed contained 78.90–69.89% water, 18.25–15.69% protein, and 2.28–12.57% fat. The energy value of the muscle tissue ranged from 93.50 to 175.83 kcal/100 g. The contents of amino acids in 100 g of protein were 47.64–45.86 g for total essential amino acids (TEAA), 52.36–54.14 g for total neutral amino acids (TNAA), 3.14–2.25 g for total sulphur amino acids (TSAA), and 7.23–7.81 g for total aromatic amino acids (TArAA). The essential amino acid (EAA) composition of the fish was compared with the standard protein, and Chemical Score (CS), Protein Digestibility-Corrected Amino Acid Score (PDCAAS), and Essential Amino Acid Index (EAAI) were calculated. The quality of the muscle tissue proteins of all four fish species was high. These fish can constitute a healthy addition to the human diet.

The aim of this study was to determine the microbiological quality of raw cow milk from direct sale points. Raw cow milk samples were collected from 5 randomly selected direct sale points for microbiological evaluation. The samples were analyzed to determine total aerobic bacterial count, somatic cell count (SCC), counts of Enterobacteriaceae, Enterococcus, Escherichia coli, and Staphylococcus, and presence of Salmonella, Listeria monocytogenes, and inhibitory substances. The mean counts of total aerobic bacterial in samples from all direct sale points were between 9.2×10(4) and 3.6×10(7) cfu/mL. Milk samples collected from 5 direct sale points revealed counts Enterobacteriaceae ranging from 6.4×10(1) to 1.7×10(6) cfu/mL. Escherichia coli were detected in 12 milk samples with counts ranging from 5.0×10(0) to 1.1×10(2) cfu/mL. Staphylococcus spp. bacteria were found in all milk samples, at counts ranging from 1.6×10(3) to 5.1×10(4) cfu/mL. Listeria monocytogenes bacteria were detected in 1 sample, and SCC in all samples ranged from 78,000 to 1,730,000/mL. The examined samples did not contain Salmonella rods or inhibitory substances. In the samples examined in this study, international hygiene standards were exceeded for total aerobic bacterial count (n=48) as well as for SCC (n=19). Two milk samples contained pathogenic bacteria (Listeria monocytogenes and Staphylococcus aureus) that pose a potential hazard for consumer health.

The current study aimed to assess the effects of dietary alpha-ketoglutarate (AKG) supplementation to laying hens on the fatty acid (FA) profile and cholesterol levels of the egg yolk at the end of production cycle. The experiment was performed on forty-eight Bovans Brown laying hens randomly assigned to either a control group (CONT) or a group supplemented with AKG. The CONT group was fed the basal diet, and the AKG group was fed the basal diet plus 1.0% AKG from the 31st until the 60th week of age, when FA profile, fat and cholesterol content of the egg yolks were determined. No significant changes in the cholesterol and total fat content of the egg yolks were observed. However, there were positive (the decrease in n-6 FA and the increase in MUFA), and negative (decrease in PUFA and n-3 FA, increase in TI and n-6/n-3 ratio) changes in FA profile following AKG supplementation. In conclusion, it was shown that dietary AKG after a 30-week long supplementation influence FA profile in egg yolk and its nutritional value.

Fish can be a valuable element of the human diet. Consequently, it is recommended in preventive and therapeutic diets. The subject of this review is a presentation of the nutritional value of fish species commercialized globally on a large scale. The content of nutrients important in terms of nutritional value was compared, and significant individual interspecies and intraspecies differences were highlighted. In addition, potential variability factors affecting the chemical composition of fish muscle tissue were shown. The presented data clearly indicated that in the case of food fish, available food nutrition tables cannot be used as universal reference data for planning a balanced diet and the current recommendations for frequency and amount of fish consumption are too general. Variability factors may substantively change the nutrient content in fish muscle tissue, even causing differences between specimens of the same species.

Artisanal cheeses can be sources of Listeria monocytogenes and cause disease in humans. This bacterial pathogen is a species of diverse genotypic and phenotypic characteristics. The aim of the study was to characterize 32 isolates of L. monocytogenes isolated in 2014–2018 from artisanal cheeses. The isolates were characterized using whole genome sequencing and bioinformatics analysis. The artisanal cheese isolates resolved to four molecular groups: 46.9% of them to IIa (1/2a-3a), 31.2% to IVb (4ab-4b-4d-4e), 12.5% to IIc (1/2c-3c), and 9.4% to IIb (1/2b-3b-7). Two evolutionary lineages emerged: lineage II having 59.4% of the isolates and lineage I having 40.6%. The sequence types (ST) totaled 18: ST6 (15.6% of the isolates), ST2, ST20, ST26, and ST199 (each 9.4%), ST7 and ST9 (each 6.3%), and ST1, ST3, ST8, ST16, ST87, ST91, ST121, ST122, ST195, ST217, and ST580 (each 3.1%). There were 15 detected clonal complexes (CC): CC6 (15.6% of isolates), CC9 (12.5%), CC2, CC20, CC26, and CC199 (each 9.4%), CC7 and CC8 (each 6.3%), and CC1, CC3, CC14, CC87, CC121, CC195, and CC217 (each 3.1%). The isolates were varied in their virulence genes and the differences concerned: inl, actA, LIPI-3, ami, gtcA, aut, vip, and lntA.

Heavy metals are introduced into water due to anthropogenic activities and can significantly affect an entire ecosystem. Due to their close integration with the water environment, fish are a sensitive indicator of contamination. In addition, fish is an important element in human diets, therefore, monitoring the concentrations of metallic contaminants in their meat is particularly important for food safety. This study aimed to assess the pollution of water ecosystems with selected toxic heavy metals in lakes Dratów, Czarne Sosnowickie, and Syczyńskie. The concentration of Pb, Cd, and Hg in water, sediment, and freshwater fish muscle tissue was determined, and a food safety assessment was performed. The analysis of water and sediments showed that the sediments were characterised by a significantly higher concentration of heavy metals. Presumably, this ecosystem element plays an important role in the uptake of heavy metal contaminants by fish whose levels were higher in planktonophagous and benthophagous fish species as compared to predatory fish. The food safety assessment showed that amounts of heavy metals in the muscle tissue posed no threat to the health of consumers ingesting that fish species, neither individually (THQ) nor collectively (TTHQ).