1197Cellulose-based foam-mat freeze-dried clove essential oil nanoemulsion as a natural food preservative

Puncharat Pilong1,2, Kazufumi Osako3, Jie-Ting Geng3 , Dharmendra K. Mishra4, Ubonrat Siripatrawan5*

1Program in Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
2Department of Food Science and Nutrition, Faculty of Agricultural Product Innovation and Technology, Srinakharinwirot University, Nakhon Nayok, Thailand
3Department of Food Sciences and Technology, Faculty of Marine Science, Tokyo University of Marine Science and Technology, Tokyo, Japan
4Department of Food Science, College of Agriculture, Purdue University, IN, USA
5Department of Food technology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand

Cellulose-based foam-mat freeze-dried clove essential oil nanoemulsion (FFD-CN) was fabricated and investigated for its efficiency to preserve food quality. The clove essential oil nanoemulsion (CN) was prepared from 1% (v/v) clove essential oil and 3% (v/v) Tween® 80 using ultrasonication. The optimal condition for fabrication of FFD-CN, optimized using response surface methodology, was found at 3% (v/v) of methyl cellulose (Methocel™) as a foaming agent, 60 °C drying temperature, and 72 h drying time. The obtained FFD-CN had the droplet size of 26.14 nm, polydispersity index (PDI) of 0.193, water activity (aw) of 0.273, solubility of 88.71%, and viscosity of 12.85 cP. The FFD-CN exhibited good stability and antimicrobial activity during 3 month storage at 25°C. The FFD-CN and CN were then applied as a natural preservative to preserve quality of shrimp. The shrimp samples were monitored for trimethylamine, total volatile basic nitrogen, total viable count, and color during chilled storage at 4 ± 2°C. The results showed FFD-CN outperformed CN for preserving the quality of whiteleg shrimp. Gas chromatography-mass spectrometry results revealed that FFD-CN can stabilize eugenol, a major volatile bioactive compound in clove oil, better than liquid-formed nanoemulsion. This suggested that methyl cellulose, due to its surface-active properties and ability to stabilize the resulting foam structures, can effectively provide a protective layer around the essential oil nanoemulsion, which improves long-term stability. FFD-CN can effectively be used as a natural preservative for maintaining the quality of shrimp