MOHSEN RADI, SOLEIMAN ABBASI*, ZOHREH HAMIDI, MOHAMMAD-HOSSEIN AZIZI

* Corresponding author

Food Colloids and Rheology Lab., Department of Food Science and Technology,
Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran

Abstract

In this study, a lecithin-based microemulsion system, as anovel technique,is introduced for extraction of edible oil. For this purpose, the pseudoternary phase diagram of canola oil/lecithin:propanol/water was constructed and the effect of temperature on the microemulsion formation was evaluated. The results showed that the microemulsion areas increased with temperature and the 2:1lecithin:propanolmicroemulsion system led toa reasonably highextraction yield (82.5%). In addition, some qualitative parameters (lower peroxide value, higher acidity and low lecithin content) of the oil which was extracted bymicroemulsionsystem werecomparable with conventional one (hexane extraction). These findings revealed the potency of lecithin-based microemulsion systemas a safe procedure to be used for extraction of edible oils.

INTRODUCTION

Microemulsions are systems composed of water, oil, and surfactants, which are single-phase, thermodynamically stable and isotropic.Some advantages of microemulsions such as thermodynamic stability, spontaneous formation, easy scale up, large interfacial area, nano-size droplets, isotropy, and low viscosity have made them applicable in many fields of science and technology (1-3). One of the successful applications of microemulsions is their use for extraction processes which even has been used at large scale applications such as enhanced oil recovery and soil decontaminations(1, 3). Microemulsions also have been applied for extraction of heavy metals (4). Biological substances such as amino acids (5), hemoglobin(6), serum albumin, and β-lactoglobulin(7) also have been extracted by microemulsion systems. High solubilization power of microemulsions for organic and inorganic compounds favors their use in extraction applications (3).
Vegetable oils are commonly extracted by mechanical pressing or by solvents. The most common extraction method of oils from oilseeds is hexane extraction which has some disadvantages. Hexane is highly volat ...