Differential scanning calorimetric analysis of edible oils: Comparison of thermal properties and chemical composition

• Published in: Journal of the American Oil Chemists' Society 2000-02, Vol.77 (2), p.143-155
• Main Authors: Tan, C. P., Che Man, Y. B.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Composition effects; Crystallization; differential scanning calorimetry; edible oil; Fat industries; fatty acid composition; Fatty acids; Food industries; Fundamental and applied biological sciences. Psychology; gas chromatography; General aspects; Glycerol; High performance liquid chromatography; Iodine; Melting; Methods of analysis, processing and quality control, regulation, standards; Plants (botany); Saturation (materials composition); thermal properties; Thermodynamic properties; triacylglycerol composition
• ISSN: 0003-021X; 1558-9331
• DOI: 10.1007/s11746-000-0024-6

The thermal profiles of 17 edible oil samples from different plant origins were examined by differential scanning calorimetry (DSC). Two other confirmatory analytical techniques, namely gas‐liquid chromatography (GLC) and high‐performance liquid chromatography (HPLC), were used to determine fatty acid (FA) and triacylglycerol (TAG) compositions. The FA and TAG compositions were used to complement the DSC data. Iodine value (IV) analysis was carried out to measure the degree of unsaturation in these oil samples. The DSC melting and crystallization curves of the oil samples are reported. The contrasting DSC thermal curves provide a way of distinguishing among these oil samples. Generally, the oil samples with a high degree of saturation (IV65). Each thermal curve was used to determine three DSC parameters, namely, onset temperature (To), offset temperature (Tf) and temperature range (difference between To and Tf). Reproducibility of DSC curves was evaluated based on these parameters. Satisfactory reproducibility was achieved for quantitation of these DSC parameters. The results show that To of the crystallization curve and Tf of the melting curve differed significantly (P