Roasting effects on fatty acid distributions of triacylglycerols and phospholipids in sesame (Sesamum indicum) seeds

• Published in: Journal of the science of food and agriculture Vol. 81; no. 7; pp. 620 - 626
• Main Authors: Yoshida, Hiromi, Abe, Sayaka, Hirakawa, Yuki, Takagi, Sachiko
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 15.05.2001; Wiley
• Subjects: Biological and medical sciences; domestic electric oven; Fat industries; fatty acids; Food industries; Fundamental and applied biological sciences. Psychology; phosphatidylcholine; phosphatidylethanolamine; phosphatidylinositol; positional distribution; roasting; sesame seeds; triacylglycerols; Heat treatment; Oilseed; Chemical analysis; Phospholipid; Lipids; Foodstuff; Antioxidant; Fatty acids; Thermal stability; Sesame seed; Electric oven; Triacylglycerol; Roasting(food); Phosphatidylcholine; Chemical composition
• ISSN: 0022-5142; 1097-0010
• DOI: 10.1002/jsfa.857

Sesame seeds were roasted at different temperatures (180–220 °C) using a domestic electric oven. The positional distribution of fatty acids in triacylglycerols (TAGs) and phosphatidylcholine (PC) isolated from total lipids in these seeds was investigated as well as the naturally occurring antioxidants that are present. Major lipid components were TAGs and phospholipids (PLs), while steryl esters (SEs), free fatty acids (FFAs) and sn‐1,3‐ and sn‐1,2‐diacylglycerols (DAGs) were minor ones. Following roasting, a significant increase (P < 0.05) was observed in FFAs and in both forms of DAG (primarily sn‐1,3‐DAG). The greatest PL losses (P < 0.05) were observed in phosphatidylethanolamine (PE), followed by PC and phosphatidylinositol (PI). On the other hand, the amounts of γ‐tocopherol and sesamin remained at over 80 and 90% respectively of the original levels after roasting at 220 °C. The principal characteristics of the positional distribution of fatty acids were still retained after 25 min of roasting: unsaturated fatty acids, especially linoleic and/or oleic, were predominantly concentrated in the sn‐2‐position, and saturated fatty acids, especially stearic and/or palmitic, primarily occupied the sn‐1‐ or sn‐3‐position. The results suggest that unsaturated fatty acids located in the sn‐2‐position are significantly protected from oxidation during roasting at elevated temperatures. © 2001 Society of Chemical Industry