[5-1015-A] Food Safety (2)

[5-1015-A-04] Cinnamon Oil Nanoemulsion as a Natural Microbial Decontaminant of Chilled Fish Flesh

Piyanan Chuesiang^1,2, Romanee Sanguandeekul¹, *Ubonrat Siripatrawan^1,2 (1. Chulalongkorn University, Department of Food Technology, Faculty of Science(Thailand), 2. The Novel Technology for Food Packaging & Control of Shelf Life Research Group, Chulalongkorn University(Thailand))

Keywords:Essential oil, Nanoemulsion , Phase inversion temperature, Antimicrobial , Cell morphology

Economic losses caused by foodborne pathogen and spoilage are a driving force to apply food preservatives in perishable food products. However, the increasing awareness in recent years of the health risks for chemical preservatives added to the increasing demands of consumers for natural antimicrobial agents. This study aimed to develop cinnamon (Cinnamomum verum) essential oil nanoemulsion (CEO-NE) as a natural fledgling microbial decontaminant of a chilled fish product. The optimum CEO-NE formulation contained cinnamon essential oil with medium chain triglyceride (MCT) = 10 wt%, a non-ionic surfactant (Tween 80) =15 wt%, and deionized water 75 wt%. The CEO-NE was fabricated using a low energy Phase Inversion Temperature (PIT) method. Sea bass fish flesh was used to represent a seafood product. The fish flesh was artificially contaminated with Escherichia coli (ATCC 25922) prior to dipping into the CEO-NE solution at its minimum inhibitory concentration (MIC) determined from the previous experiments. The samples were stored at 4 C. The growth of E. coli and total viable counts of the CEO-NE treated samples was examined in comparison to those treated with bulk CEO and untreated (control) samples. The results showed that CEO-NE effectively inhibited E. coli and total aerobic bacteria better than bulk CEO. The bacterial cell morphological deformation by the CEO-NE was evidenced by field emission scanning electron microscopy (FE-SEM). The antimicrobial activity of the CEO-NE against E. coli was attributed to its ability to disrupt bacterial cell wall structures and promote expulsion of internal cellular material. The results suggest that the encapsulation of cinnamon oil in nanoemulsion enhanced its bactericidal activity against the targeted foodborne microorganism. The developed CEO-NE has potential to be used as natural antimicrobial agent for ensuring food safety of fish flesh or other seafood products.