title: Dehulling and microwave pretreatment effects on the physicochemical composition and antioxidant capacity of virgin rapeseed oil.
abstract: The effect of microwave heating (800 W) of whole and dehulled rapeseeds for 2 to 8 min was investigated in order to evaluate the impact of dehulling in conjunction with microwaving on the nutritional value, antioxidant activity and physicochemical properties of virgin rapeseed oil. Control oil produced from dehulled seeds (DRO) had higher amounts of bioactive compounds, such as tocochromanols and phytosterols, lower content of pigments, and higher content of primary and secondary oxidation products compared to oil pressed from whole seeds (WRO). Oils pressed from seeds that had previously undergone thermal treatment demonstrated gradual increase of oxidative stability, radical scavenging activity, moreover microwave treatment to caused darkening of oil, assessed in terms of changes in L*a*b* coordinates as well as browning index. Thermally-induced compositional changes were seen mainly in canolol, phytosterols, and carotenoids content, while only slight increase of tocopherols and phenolics was observed. The most pronounced effect of microwave pretreatment was noted for canolol formation-for 8-min MV exposure canolol quantity was approximately 7- and 23-fold higher, in comparison with control WRO and DRO samples, respectively (increase from 61.39 to 456.04 µg/g, and from 13.39 to 320.44 µg/g).
authors.affiliation: Department of Food Technology, Faculty of Food Sciences, Warsaw University of Life Sciences, Nowoursynowska St. 159c, 02-787 Warsaw, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Rękas
authors.affiliation: Department of Food Biochemistry and Analysis, Faculty of Food Sciences and Nutrition, Poznań University of Life Sciences, Wojska Polskiego St. 28, 60-637 Poznań, Poland.
authors.forename: Aleksander
authors.initials: A
authors.lastname: Siger
authors.affiliation: Department of Food Technology, Faculty of Food Sciences, Warsaw University of Life Sciences, Nowoursynowska St. 159c, 02-787 Warsaw, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Wroniak
authors.affiliation: Department of Food Technology, Faculty of Food Sciences, Warsaw University of Life Sciences, Nowoursynowska St. 159c, 02-787 Warsaw, Poland.
authors.forename: Iwona
authors.initials: I
authors.lastname: Ścibisz
authors.affiliation: Department of Biotechnology, Microbiology and Food Evaluation, Faculty of Food Sciences, Warsaw University of Life Sciences, Nowoursynowska St. 159c, 02-787 Warsaw, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Derewiaka
authors.affiliation: Department of Machines and Research Methodology, Faculty of Technical Sciences, University of Warmia and Mazury in Olsztyn, M. Oczapowskiego St. 11, 10-736 Olsztyn, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Anders
keywords: Bioactive compounds; Dehulling; Microwave treatment; Physicochemical properties; Radical scavenging activity; Rapeseed oil