Liquid and gas chromatographic analyses of triacylglycerols for Asian sesame oil traceability

Abstract

This study aimed to investigate the triacylglycerol (TAG) composition of Asian sesame oils and to differentiate the geographic origins of the oils using the analytical data in combination with canonical discriminant analysis (CDA). The TAG compositions of 51 Korean, 19 Chinese, and 14 Indian sesame oil samples were analyzed by liquid chromatography‐evaporative light scattering detector (LC‐ELSD) and GC‐FID, separately. The TAG content values determined by LC‐ELSD showed strong positive linear correlation to those measured by GC‐FID. The CDA results showed that good discrimination (hit ratio, ∼92%) between the oil samples was achieved by applying the respective canonical variables generated from the LC‐ELSD and GC‐FID data. The CDA using GC‐FID data accurately characterized the origins of all the four additional commercial oil samples (two Korean and two Chinese products), whereas the CDA using LC‐ELSD data correctly characterized the origins of only two samples. This study demonstrated that both LC‐ELSD and GC‐FID analyses of TAG compositions were useful tools for characterizing the geographic origin of the oils and the separation of the Korean sesame oils from the other two groups of oils using the GC‐FID data was more efficient than that using the LC‐ELSD data.Practical applications: The simplicity and universality of GC‐FID and LC‐ELSD make the analysis of TAG composition using these chromatographic systems a practical and feasible procedure for tracing the geographic origin of the sesame oils. The combination of TAG analysis with methods to analyze different constituents in sesame oils would enhance the accuracy of the oil traceability.Score plots of two canonical variables derived from CDA using liquid chromatography‐evaporative light scattering detector (LC‐ELSD) data and GC‐FID data for the Korean, Chinese, and Indian roasted sesame oils.