POMEGRANATE SEED OIL: EXTRACTION, SHELF LIFE PREDICTION, AND MICROENCAPSULATION

Abstract

Interest in oils rich in polyunsaturated fatty acids has increased in recent years about their beneficial effects on human health. Pomegranate seed is an industrial by-product that has a large variety of nutritional value. Pomegranate seed oil (PSO) has an exceptional fatty acid profile. Lipid oxidation is one of the important parameters that limits its use in food products. Thus, the objectives of this study were to evaluate the effects of extraction methods (Soxhlet and stirring) and solvents (n-hexane, petroleum ether, diethyl ether, and ethanol) on oxidation parameters in the extraction of PSO, to predict the shelf life of PSO by Rancimat and to encapsulate PSO by spray drying to extend its shelf life. PSO yield varied between 1.88 and 14.32%. The lowest peroxide (2.88 meq O2/kg), p-Anasidine (6.56 meq p- Anisidine/kg), and TOTOX (12.13) values were observed when PSO was extracted by stirring using n-hexane as solvent. The shelf lives of PSO at 0, 4, and 20 oC using Rancimat were predicted as 11593, 8088, and 1916 h, respectively. The main fatty acid in PSO was punicic acid and derivatization had a significant effect on the determination of punicic acid by GC (sodium methoxide, 84.75% and potassium hydroxide, 81.79%). Inlet air temperature of 140 degrees C, oil: wall material ratio of 1:2 (w/w), and maltodextrin: gum Arabic ratio of 1:1 (w/w) were selected as favorable conditions in microencapsulation of PSO. The addition of antioxidants into feed solutions had no positive effects on oxidation during spray drying.