Characterization of Wheat Germ Oil in Terms of Volatile Compounds, Lipid Composition, Thermal Behavior, and Structure

Abstract

In this study, the volatile compounds, lipid composition, thermal behavior, and structure of wheat germ oil were analyzed. Forty-four volatile compounds, mainly alcohols, esters, alkenes, and aldehydes, were isolated by headspace solid phase micro extraction. The major constituents were found to be hexanal (15.97%), 2-methyl-2-butene (10.43%), 2,4-heptadienal (8.53%), and limonene (6.83%). The oil was rich in unsaturated fatty acid (83.45%), especially in linoleic acid (64.82%), and there were 75.49% unsaturated fatty acid distributed in Sn-2 position. The main content of unsaponifiable matters was sterol, especially β-sitosterol (64.64%). The thermogravimetric analysis results showed one major regime of weight loss over a temperature range of 280–500°C and an exothermic behavior was observed by the differential scanning calorimetry data.

Keywords:

• Wheat germ oil
• Volatile compounds
• Triacylglycerol
• Thermal behavior

ACKNOWLEDGMENTS

This work was financially supported by the National Key Technology Research and Development Program in the 11th Five Year Plan of China (2010BAD01B07), and the High-Tech Research and Development Program of China (2010AA101503).