Grapevines (Vitis spp.) produce several valuable polyphenol-type secondary metabolites including various stilbenoids. Although the potential application of stilbenes may offer alternative solutions to food safety or health challenges, only little information is available on their antibacterial activity against foodborne pathogens. In this work, high-performance liquid chromatography was used to analyze the stilbenoid profile of various wild Vitis species, including V. amurensis, V. davidii, V. pentagona, and V. romanetii, selected from the gene bank for grapes at the University of Pécs, Hungary. We found that the stilbene profile of cane extracts is strongly genotype-dependent, showing the predominant presence of ε-viniferin with a wide concentration range ≈ 320–3870 µg/g dry weight. A novel yet simple and efficient extraction procedure was developed and applied for the first time on grape canes, resulting in ε-viniferin-rich crude extracts that were tested against Listeria monocytogenes, an important foodborne pathogen. After 24 h exposure, V. pentagona and V. amurensis crude extracts completely eliminated the bacteria at a minimum bactericidal concentration of 42.3 µg/mL and 39.2 µg/mL of ε-viniferin, respectively. On the other hand, V. romanetii extract with 7.8 µg/mL of ε-viniferin resulted in 4 log reduction in the viable bacterial cells, while V. davidii extract with 1.4 µg/mL of ε-viniferin did not show significant antibacterial activity. These findings indicate that the ε-viniferin content was directly responsible for the antibacterial effect of cane extract. However, pure ε-viniferin (purity > 95%) required a higher concentration (188 µg/mL) to eradicate the bacteria under the same conditions, suggesting the presence of other antibacterial compounds in the cane extracts. Investigating the onset time of the bactericidal action was conducted through a kinetic experiment, and results showed that the reduction in living bacterial number started after 2 h; however, the bactericidal action demanded 24 h of exposure. Our results revealed that the canes of V. pentagona and V. amurensis species are a crucial bio-source of an important stilbene with antimicrobial activity and health benefits.

Background: Wine production generates significant amounts of grape marc, which can serve as a potential source of bioactive compounds, including polyphenols. Objectives: In this study, we aimed to investigate the polyphenol content of skin and seeds separated from grape marc, and test their extracts against two significant bacteria, Listeria monocytogenes (LM) and Staphylococcus aureus (SA). Methods: A comprehensive analysis of the phenolic composition in the skin, seeds, and juice/wine derived from Cabernet Sauvignon grape berries was conducted over an 18-day fermentation period. High-performance liquid chromatography was performed to identify and quantify the main flavan-3-ols, flavonols, anthocyanins, and stilbenes. In addition, the total phenolic content (TPC) was determined by the Folin–Ciocalteu method. Results: The TPC of both seeds and skins significantly decreased over time. In parallel, the TPC in the wine gradually increased, indicating a release of phenolic compounds into the wine. We found that the TPC in seeds was consistently higher than in the skin at all examined time points. The main flavonoids in seeds were flavan-3-ols (catechin and epicatechin), while anthocyanins (delphinidin-, cyanidin-, petunidin-, peonidin-, and malvidin-3-O-glucoside) were the predominant ones in skins. Crude seed and skin extracts enriched in phenolics were prepared, of which only the crude seed extract was proven effective against LM and SA. Following the time-kill assay, our findings revealed that the minimal bactericidal concentration of the crude seed extract against LM was 5.02 mg/mL after 12 h incubation, demonstrating the eradication of the living bacterial cell number by ~6 log. A 24 h exposure time was required for complete inactivation of SA, but a lower concentration was sufficient (2.54 mg/mL). Conclusions: Grape waste remains a valuable source of polyphenols, with grape seeds, in particular, exhibiting significant antimicrobial activity against certain foodborne pathogens.

Polyphenols are plant secondary metabolites widely recognized for their antioxidant properties and potential health benefits. Grapevine leaves are a rich yet underexplored source of these bioactive compounds. In this study, caftaric acid, and predominant flavonol glycosides were characterized in leaves of seventeen grapevine genotypes by high-performance liquid chromatography, while total phenolic content (TPC) was determined using the Folin–Ciocalteu assay. In addition, the growth-promoting effect of a polyphenol-rich Vitis amurensis leaf extract on Lactiplantibacillus plantarum and its protective effect under H₂O₂-induced oxidative stress were evaluated. Both TPC and phenolic composition were strongly genotype-dependent, with TPC ranging from approximately 20 to 100 mg gallic acid equivalents (GAE) g⁻¹ dry weight (DW). Quercetin and kaempferol glycosides were the predominant flavonols, and quercetin-3-O-glucuronide, one of the most abundant derivatives, varied nearly tenfold among genotypes (approximately 2100–20,000 mg kg⁻¹ DW). The leaf extract of V. amurensis, the genotype with the highest TPC, significantly promoted the in vitro growth of L. plantarum in a dose-dependent manner, resulting in higher viable cell counts after 24 h. The extract also markedly enhanced bacterial survival under H₂O₂-induced oxidative stress. At 2 mM H₂O₂, no bacterial growth was detected in the absence of the extract, whereas extract-supplemented cultures maintained substantial growth and reached a viable cell count of 1.8 × 10⁸ colony-forming units (CFU) mL⁻¹ after 24 h. The phenolic patterns identified across the investigated genotypes provide a basis for selecting Vitis genotypes as sources of specific flavonol glycosides. Furthermore, our microbiological results provide preliminary evidence of the beneficial effects of V. amurensis leaf extract on L. plantarum and warrant further investigation of its potential functional applications.

Canned fish products enable long-term preservation of fish, a vital source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Despite research on lipid composition, gaps remain in understanding the bidirectional fatty acid (FA) exchange between fish muscle and coating media during processing and storage. After a systematic literature search across five databases (PubMed, Scopus, Web of Science, Wiley Online Library, Cochrane Library), 20 studies were included examining FA profiles across fish species, filling media (vegetable oils, brine, tomato sauce), and storage durations (up to 5 years). Five studies showed that n-3 FAs migrate from fish to the filling medium, enhancing its nutritional value, while fish muscle absorbs FAs from the oil, increasingly resembling the filling medium. The use of n-6 FA-rich oils (sunflower, soybean) lowered the n-3/n-6 ratio in flesh. Conversely, aqueous media (brine) and tomato sauce maintained better ratios. EPA and DHA content generally decreased due to canning and storage, with retention varying by fish species, filling medium, and sterilization method. This review underscores significant FA exchange between fish and filling media, confirming bidirectional lipid interchange during processing. To optimize health benefits, aqueous packing media are recommended to preserve lipid profiles or to consume the covering oil to recover nutrients. Further research is needed on other factors altering FA content in canned fish such as environmental and geographical variables (including catching season), pre-canning preparation and sterilization steps (such as freezing, steaming, and frying), sterilization conditions (time, temperature, F₀ value) and lipid oxidation induced by thermal processing.