14B-10
Production and characterization of emulsifier-based nanoparticles to encapsulate phytophenol antimicrobials
S. G. SEGURA, P. M. Davidson, and J. Weiss. Dept. of Food Science & Technology, Univ. of Tennessee, 2605 River Dr., Knoxville, TN 37996-4500
Phytophenols such as eugenol and carvacrol are antimicrobials that can inhibit growth of foodborne pathogens. However, their activity in food systems is reduced because of low solubility and/or interference from food components. Encapsulation in nanoparticles may offer a new method to increase solubility in the aqueous phase.
The objective of this study was to determine properties and efficiency of encapsulation of phytophenols in emulsifier-based nanoparticles.
Aqueous Surfynol 485W and Surfynol 465 solutions were prepared at 1, 2, 3.5, 5, 7.5 and 10%w/w. Eugenol (2-methoxy-4-(2-propenyl)-phenol) and carvacrol (2-methoyl-5-(1-methylethyl)phenol) were added to emulsifier solutions at concentrations ranging from 0.05-5wt%. Solutions were continuously shaken to initiate encapsulation and turbidity of solutions was measured after equilibration for 24h. Size of nanoparticles was determined using dynamic light scattering prior to and after encapsulation.
Turbidity decreased within 10min. upon addition of carvacrol and eugenol to surfactant solutions indicating that nanoparticles rapidly incorporated phytophenols. Below the maximum additive concentration (MAC), carvacrol and eugenol were completely encapsulated and solution turbidity became zero. The MAC increased with increasing Surfynol concentration, .e.g., the MAC of carvacrol in 7.5wt% S.485W was 1wt% compared to ~0.2wt% in 2wt% S.485W solution. The rise in MAC with increasing emulsifier concentration depended on molecular properties of both emulsifier and antimicrobial (Figure 1). S.465 was more efficient than S.485W in encapsulating both eugenol and carvacrol. Dynamic light scattering showed that the size of the empty nanoparticles was 15 and 52nm, for S.485W and S.465 respectively and increased to 43 and 123nm, upon incorporation of phytophenols. Nevertheless, nanoparticles were thermodynamically stable and no change in size was observed for 2 months.
Results show that encapsulation of phytophenols in surfactant nanoparticles dramatically increases solubility solving the major problem that currently prevents phytophenols application in many food systems.
Session 14B, Food Chemistry: Physicochemical properties
8:30 AM - 12:00 PM, Sunday AM