TIChE International Conference 2011 November 10 – 11, 2011 at Hatyai, Songkhla THAILAND Paper Code: ms023 ms023‐1 Nano-Particle Emulsion from Coconut Oil Using High Pressure Jet M. N. Eshtiaghi 1*, K. Phurahong 1,* , G. Puengpipattrakul 1 J. Kuldiloke 1 Department of Chemical Engineering, Faculty of Engineering, Mahidol University, Nakornpathom, 73170, Thailand *e-mail: egmne@mahidol.ac.th __________________________________________________________________________________ Abstract - The Effects of high hydrostatic pressure jet (HPJ) on oil droplet size of virgin coconut oil (VCO) during injection of oil in the mixture of emulsifier and water was studied.. Pressure level as well as emulsifier concentration had distinct effect on oil droplet size of HPJ treated samples. Increasing the pressure from 1000 bar to 3000 bar and surfactant concentration (up t0 19% w/w) resulted decreasing of oil droplet size. In contrast, oil concentration between 2 to 10% (v/w) have no or slight effect on oil droplet size in nano emulsion. HPJ application resulted oil droplet size reduction of about 165 nm- 360 nm in very short treatment time (less than 1 min). In addition, the effects HPJ on turbidity, emulsion stability, and viscosity of prepared nano-emulsions were studied. Keyword: Nano-emulsion, High Hydrostatic Pressure Jet, coconut oil _________________________________________________________________________________ 1. Introduction Nano-emulsions are oil-in-water (o/w) or water-in- oil (w/o) transparent or translucent colloidal dispersions; usually in the 20–500 nm size range [1]. Nano- emulsions are thermodynamically stable solutions containing nano-sized droplets of an immiscible liquid dispersed in another liquid. [3]. Nano-emulsions have a number of advantages over larger scale emulsions. They can be stabilized to increase the shelf life of products particle size. They are suitable to carry active ingredients. The basic color of emulsions is white. If the emulsion is dilute, the Tyndall effect will scatter the light and distort the color to blue ; if it is concentrated, the color will be distorted towards yellow. Microemulsions and nano-emulsions tend to appear clear due to the small size of the disperse phase. High- pressure homogenization is a technology that has been applied for many years in various area for the production of emulsions and suspension. A distinct advantage of this technology is its ease for scaling up, even to very large volumes. Most of the homogenizers used are based on the piston-gap principle, an alternative is the jet stream technology. Marie et al. (2002) investigate the effect of high pressure (up to 350 MPa) on producing of oil-in-water emulsions with or without Tween 20 as an emulsifier. An increase in the oil content leads, without emulsifier, to an increase in the particle size at both 200 and 350MPa. Virgin coconut oil (VCO) is growing in popularity as functional food oil and the public awareness of it is increasing. It is expected that VCO will experience a dramatic growth in the market. Virgin coconut oil is oil extracted from fresh coconut (not copra) meat by mechanical or natural means. It can be obtained with or without using heat. To protect the oil’s essential properties, the production of virgin coconut oil does not undergo chemical refining, bleaching, or deodorizing. Said to be high in vitamins and minerals, it is fit for consumption without the need for further processing. Virgin Coconut oil has been documented as having more beneficial effects in clinical trials such as Strengthen skin tissues, Repair skin damage, Preventing wrinkles, Prevents destructive free-radical formation. [2]. The aim of this study was to produce nano-emulsion from coconut oil using High Pressure Jet (HPJ) as a novel technique and to determine the physical properties of produced nano-emulsions (Oil droplet size, turbidity, viscosity, refractive index and emulsion stability). 2. Materials and Methods 2.1 Materials The in Mahidol University prepared cold pressed, deodorized (using activated carbon) virgin coconut oil was used as raw material. Polysorbate 80 (Tween 80),was used as emulsifier. Response Surface Methodology (RSM) with 3 variables (pressure, oil content, surfactant concentration) by using Box-Behnken designs was applied for HPJ to find out the effect of pressure level, surfactant concentration and oil content on oil droplet size as well as the properties (stability, turbidity measurement, transparency).of prepared nano emulsion. 3 variables, emulsifier concentration (X1=3, 11, 19%), oil content (X2= Oil content 2, 6, 10 %) and pressure