Determination of Hexanal Using Static Headspace GC-FID Method and Its Correlation with Oxidative Rancidity in Edible Oils

A static headspace gas chromatography coupled with flame ionisation detector (SHS-GC-FID) has been used to develop a method for the identification and quantification of hexanal in various fresh and stored edible oils to assess their oxidative rancidity. The optimization has been done for three parameters, i.e. time, temperature and amount of sample. The method has been validated for linearity, limit of detection and quantification, accuracy, precision and recovery. The SHS-GC method has been successfully applied to six types of edible oils, i.e. soybean, sunflower, coconut, mustard, rice bran and palm oil. Simultaneously, oxidative rancidity parameters have been determined, and Pearson’s correlation analysis has been done between these parameters and hexanal concentration. The results clearly demonstrated positive correlation between the main oxidative rancidity indicating parameters and hexanal concentration. Also, the effect of storage at two different temperatures (25 °C and 45 °C) on the hexanal concentration in edible oils has been monitored for 3 months.