Fruit and fruit juices are a valuable source of bioactive compounds, which can protect our organisms from oxidative stress. The phenolic compounds and other phytochemicals may affect the antimicrobial properties of juices. The aim of this study has been to evaluate antioxidant and antimicrobial properties of selected berry juices and vitamin C-rich fruit juices. The research material was composed of seven juices, including three from berries (elderberry chokeberry, cranberry), three from vitamin C-rich fruit (sea buckthorn, wild rose, Japanese quince) and one exotic juice from noni fruit. Antioxidant capacity, total polyphenol, total flavonoid and total anthocyanin content were determined. Furthermore, the antimicrobial activity and the minimal inhibitory concentration (MIC) as well as the minimal bactericidal concentration (MBC) were evaluated. The research showed that fruit juices from wild rose, chokeberry and Japanese quince had the highest antioxidant capacity. These juices were characterised by the rich content of polyphenols. Elderberry and chokeberry juices had the highest total anthocyanins. The juices differed in the content of bioactive compounds and specific bactericidal properties against Gram-positive or Gram-negative bacteria. Fruit juices from cranberry, Japanese quince and sea buckthorn had the highest antimicrobial activity. Wild rose, chokeberry and elderberry juices, despite their high antioxidant properties, showed antimicrobial activity only against Gram-positive strains, except Enterococcus faecalis and Clostridium perfringens. Significant differences in the content of bioactive compounds in fruit juices affect the antimicrobial properties juices.

Group A Streptococci (GAS) or Streptococcus pyogenes is responsible for acute bacterial pharyngitis in children as well as adults. Streptococcal pharyngitis is initiated by successful attachment and colonization of the bacteria, followed by the establishment of the biofilm in various environments. In this study, we examined the antibacterial activities of in-house prepared aqueous and ethanolic extracts of 10 Atlantic Canada fruits in the context of minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), time-kill kinetics, and adhesion inhibition properties against S. pyogenes. Per our findings, MIC and MBC for all the tested extracts ranged from 0.25 to 8 mg/mL and from 4 to 64 mg/mL, respectively. Accordingly, at 1/2 x MBC, cranberry and sumac extracts also lowered the attachment of GAS to the uncoated and fibronectin-coated substratum. Particularly, cranberry and sumac aqueous extracts were more effective against the adhesion of S. pyogenes ATCC 19615 to the fibronectin-coated surface than a clinical strain. In conclusion, ethanolic and aqueous extracts of cranberry and sumac could potentially be incorporated into natural health products designed for the amelioration of strep throat, yet a detailed understanding of its mode of action (e.g., biofilm inhibition and eradication) could pave its path to the field of antibacterial natural health product discovery, design, and development.

Research about biodegradable antimicrobial films continues to receive a lot of attention due to the plastic pollution crisis and the need for environment-friendly and safe food products. In this study, we developed chitosan-based antimicrobial films using a combination of encapsulated lemon essential oil (LEO) by ionic gelation and cranberry juice and evaluated the performance of the films. Our results indicated that the incor-poration of LEO microspheres and cranberry juice into the chitosan films improved the UV barrier and thermal properties as well as antioxidant activity of the films. The increase in antioxidants was consistent with the chemical components in LEO and cranberry juice as determined by GC-MS; some of which possess antioxidant properties. Furthermore, following antimicrobial activity test, considerable inhibition halo of 11 and 20 mm were observed respectively against fungi Candida albicans and Penicillium roqueforti, particularly in presence of the film containing both LEO microspheres and cranberry juice.