Influence of de-hulled rapeseed roasting on the physicochemical composition and oxidative state of oil

• Main Authors: A. Rękas, A. Siger, M. Wroniak, I. Ścibisz, D. Derewiaka, A. Anders
• Format: Article
• Language: English
• Published: Consejo Superior de Investigaciones Científicas 2017-03-01
• Series: Grasas y Aceites
• Subjects: bioactive compounds; de-hulling; oxidative stability; radical scavenging activity; rapeseed oil; roasting
• Online Access: http://grasasyaceites.revistas.csic.es/index.php/grasasyaceites/article/view/1642

The effect of roasting time on the contents of bioactive compounds (tocopherols, phytosterols, phenolic compounds), antioxidant capacity and physicochemical properties of rapeseed oil pressed from de-hulled seeds was investigated. The de-hulled seeds were roasted at a temperature of 165 °C for 20, 40, 60, 80, and 100 min. The results of this study show that a roasting pre-treatment led to a gradual increase in canolol content (from 1.34 to 117.33 mg/100 g), total phytosterols (from 573.51 to 609.86 mg/100 g) and total carotenoids (0.82 to 2.41 mg/100 g), while only slight changes in the contents of tocopherols were noted. With the increase in roasting time a gradual increase in oxidative stability (from 4.27 to 6.85 h), and antioxidant capacity, seen mainly in the hydrophilic fraction of oil (from 0.32 to 2.30 mmol TEAC/l) was found. Although roasting resulted in the formation of primary and secondary oxidation products, the quality parameters of oils were within Codex Alimentarius limits.