Anti-bacterial Activities of EGCG Nanoparticles

OBJECTIVES: Active packaging based on natural phytochemicals is of great importance in food preservation against quality degradation, spoilage, and waste generation, and in food safety against foodborne outbreaks. Epigallocatechin gallate (EGCG), a major green tea catechin, has antioxidant and antimicrobial properties. It is, however, unstable and easily degraded during storage. Nanoencapsulation can overcome this issue. The objective of this project is to make biocompatible EGCG-encapsulated lipid nanoparticles (EGCG-NPs) and determine their anti-bacterial activities using Salmonella enteritidis, Escherichia coli, and Staphylococcus aureus. METHODS: EGCG-NPs were prepared using soy phosphatidylcholine, α-tocopherol acetate, α-tocopherol nicotinate, surfactant, EGCG by a sonication method. The size and polydispersity index of NPs were measured using Zetasizer Pro. EGCG-NPs were applied on chitosan-soaked nanofiber, and their anti-bacterial activities were determined using Salmonella enteritidis, Escherichia coli, and Staphylococcus aureus. The number of bacteria was determined by counting the colony forming unit formed on the agar plates. RESULTS: EGCG encapsulation efficiency was more than 90%. The mean particle size of EGCG-NPs was about 70 nm. Their polydispersity index was less than 0.2. The anti-bacterial activity of EGCG-NPs was more potent in Salmonella enteritidis than it in Escherichia coli, and Staphylococcus aureus. EGCG-NPs killed about 80% of Salmonella enteritidis after 1-hour incubation. CONCLUSIONS: EGCG-NPs was successfully prepared. EGCG-NPs had potent anti-bacterial activities, especially to Salmonella enteritidis. FUNDING SOURCES: Arizona State University.