β-Sitosterol and campesterol stabilisation by natural and synthetic antioxidants during heating
Author: Dominik Kmiecik and Józef Korczak and Magdalena Rudzińska and Joanna Kobus-Cisowska and Anna Gramza-Michałowska and Marzanna Hęś
The aim of this study was to estimate the effect of natural and synthetic antioxidants in protecting phytosterols during heating at 180 °C. Green tea extract, rosemary extract, a mix of tocopherols from rapeseed oil, a mix of synthetic tocopherols, phenolic compounds extracted from rapeseed meal, sinapic acid and BHT were used. After 4 h of heating in oxygen atmosphere β-sitosterol and campesterol oxidation products (7α- and 7β-hydroxysterol, 5α,6α- and 5β,6β-epoxysterol, 7-ketosterol and triols) were estimated by GC. Total content of phytosterol oxidation products in samples ranged from 137 to 374 mg/kg of sample. The effectiveness of antioxidants decreased in the following order: synthetic tocopherols > green tea extract > natural tocopherols from rapeseed oil > rosemary extract > phenolic compounds extracted from rapeseed meal > sinapic acid > BHT.
