Lipid and phytochemicals profiles of non heat treated virgin coconut oil

Abstract

The production of virgin coconut oil (VCO) was carried out using three processing methods; the wet, dry and integrated wet process. The highest processing temperature was set at 50ºC in order to preserve the heat labile components in VCO. In this study, the yield, the chemical composition, minor bioactive components, descriptive sensory analysis and lipid profiles were investigated. The VCO yield (%) from the wet, dry and integrated wet process was 19.82±0.46%, 43.28±2.0% and 36.71±1.6% respectively. VCO extracted by integrated wet process exhibit the highest quality of oil in addition to preservation of the minor bioactive compounds; a-tocopherol (40.0±0.11 ppm) and polyphenol (4.34 ± 0.09mg GAE/g oil). Eventhough the yield were slightly lower than dry process, the concentration of the labile compounds was higher. VCO extracted by wet process appeared colorless and exhibited a slight detectable rancidity. On the other hand, VCO extracted by integrated wet process was clear in appearance, sweet in aroma, taste and flavor. The VCO extracted by dry process was slightly yellow in colour and had nutty aroma and flavor. The lipid profiling study was carried out using Ultra Performance Liquid Chromatography- Electrospray Ionization - tandem Mass Spectrometry (UPLC-ESIMS/ MS). The lipid profiles of coconut oil indicated that the neutral lipids accounted for 17.4% of the total lipid formed. Meanwhile, 82.6% was accounted for polar lipids with the value for phospholipids, glycolipid and sphingolipid of 21.5%, 33.0% and 45.4%, respectively. VCO extracted by integrated wet process contain only triacylglycerols (TAG) while the wet and the dry process exhibit diacylglycerides (DAG), monogalactosyl diacylglycerides (MGDG), suloquinorosyl diaclyglycerides (SQDG) and digalactosyl diacylcerides (DGDG). The present study using UPLCESI- MS/MS to profile the lipid content of VCO demonstrated that the integrated wet process is better than the wet and dry process in preserving the minor components and TAG.