ABSTRACT
Propolis is a naturally occurring substance with beneficial properties; bees produce it from various plant sources, and it is an anti-inflammatory and therapeutic resinous substance. This study aimed to enhance the biological features of propolis extract by loading it onto active film. Firstly, extraction was performed using three solvent systems, and their total phenolic, flavonoid, and antioxidant activity was measured. Propolis ethanol extract (EEP) was evaluated for phenolic fraction content and then chosen to prepare a chitosan-loaded emulsion with several concentrations. The antibacterial, anti-mycotic, and anti-mycotoxigenic properties of the extract and nanoemulsion were assessed. PPE's cytotoxicity and nanoemulsion were evaluated using brine shrimp and cell line assays. Results indicate higher phenolic (322.57 ± 4.28 mg GAE/g DW), flavonoid (257.64 ± 5.27 mg QE/g DW), and antioxidant activity of the EEP. The phenolic fraction is distinguished by 18 phenolic acids with high p-hydroxybenzoic content (171.75 ± 1.64 µg/g) and 12 flavonoid compounds with high pinocembrin and quercetin content (695.91 ± 1.76 and 532.35 ± 1.88 µg/g, respectively). Phenolic acid derivatives (3,4-Dihydroxybenzaldehyde, 3,4-Dihydroxyphenol acetate, and di-methoxy cinnamic) are also found. Concentrations of 50, 100, 150, and 200 ng EEP loaded on chitosan nanoemulsion reflect significant antibacterial activity against pathogenic bacteria, particularly methicillin-resistant Staphylococcus aureus (MRSA) and toxigenic fungi, particularly Fusarium. Among the four EEP-loaded concentrations, the nanoemulsion with 150 ng showed outstanding features. Using a simulated medium, 150 and 200 ng of EEP-loaded chitosan nanoemulsion concentrations can stop zearalenone production in Fusarium media with complete fungi inhibition. Also, it reduced aflatoxins production in Aspergillus media, with fungal inhibition (up to 47.18%). These results recommended the EEP-chitosan application for pharmaceutics and medical use as a comprehensive wound healing agent.
ABSTRACT
Natural antibacterial agents such as citrox are effective against many foodborne pathogens and foods contaminated with bacteria. We studied the antimicrobial effects of citrox solutions (1% and 2%) on the total viable counts of methicillin-resistant Staphylococcus aureus (MRSA) in chicken meat fillets. The total coliform group counts found in the chicken samples were also determined. The samples were treated with S. aureus at a concentration of 106 colony-forming units (cfu)/g of meat and vacuum-packed (VP) at 4 °C for 3, 6, 9, 12, 15, 18, and 21 days. We also studied the effect of citrox on the total volatile basic nitrogen (TVBN) content and pH changes during the storage period of the meat samples. The results revealed that citrox inhibited the growth of MRSA in the chicken fillets. The total viable counts of MRSA decreased after treatment with 2% citrox in all treated samples that were stored at 4 °C by approximately 2 log units compared with the samples inoculated with S. aureus (Chicken-Staph groups) after 3, 6, 9, and 12 days of storage, and by approximately 1 log unit compared with the control samples treated with salt (Chicken-Salt groups) after 3, 6, and 9 days of storage. TVBN was reduced in the Chicken-Citrox-treated samples stored at 4 °C compared with the Chicken-Staph- and Chicken-Salt-treated samples. The results indicated that citrox is effective in reducing the total counts of MRSA and in improving the quality of chicken during the first three days of storage by reducing the number of bacteria by 1 log unit and extending the shelf life of chicken.
