Effect of Roasting Conditions on the Chemical and Functional Properties of Oat Oil

Oats (Avena sativa) are a nutritionally dense cereal crop. They are appreciated for their characteristic flavour and high levels of essential nutrients, particularly high-quality oil enriched with unsaturated fatty acids and antioxidants. This study evaluates the influence of various roasting conditions on oat oil's chemical composition and functional quality. Roasting, a widely used food processing method, enhances flavour and digestibility while inducing structural and compositional modifications in cereal grains.

Oat grains were roasted at different temperatures, and the oil was extracted using Soxhlet and supercritical carbon dioxide methods. Gas Chromatography (GC) was used to analyse the fatty acid composition, and oxidative stability was measured using Pressure Differential Scanning Calorimetry (PDSC). The peroxide and acid values were analysed using standard titrimetric methods. Molecular-level changes in the oil were examined using Fourier Transform Infrared (FTIR) spectroscopy within the 4000–400 cm⁻¹ range, followed by chemometric analysis.

The results demonstrate that roasting significantly affects the yield and quality of oat oil. Roasting at slightly higher temperatures, specifically between 160°C and 190°C for 20 to 50 minutes, enhances the oil's ability to resist oxidation. FTIR spectroscopy and multivariate statistical tools effectively distinguished roasted from unroasted samples, revealing distinct thermal-induced alterations in the oil's chemical profile. These findings contribute to a deeper understanding of how thermal processing impacts oat oil's nutritional and functional properties, offering valuable implications for developing health-oriented food products.