Influence of roasting pretreatment on high‐oleic rapeseed oil quality evaluated by analytical and sensory approaches

Abstract

Summary Qualitative and quantitative effects on the contents of minor components of cold‐pressed high‐oleic rapeseed oil (HORO) were evaluated in a function of different roasting temperatures (80, 100, 120 and 140 °C). Along with roasting temperature elevation, a significant increase in the content of total tocopherols up to 32% (mainly γ‐T homologue) and a slight increase of total sterols concentration (up to 5%) were observed, whereas no significant changes in the fatty acid composition occurred during seeds thermal pretreatment. Additionally, an increased degree of hydrolysis and lipid oxidation was reported; however, obtained results were within codex limits. The peroxide value of the oil ranged from 1.30 to 2.34 mEq O 2 kg −1 , while the acid value did not exceed 0.46 mg/KOH g. Principal component analysis was capable of differentiating between rapeseed oils acquired from seeds pretreated with different roasting temperatures.