Impact of Canolol-Enriched Extract from Heat-Treated Canola Meal to Enhance Oil Quality Parameters in Deep-Frying: a Comparison with Rosemary Extract and TBHQ-Fortified Oil Systems
Canolol-enriched extracts obtained from the extraction of fluidized bed treated canola meal with super-critical carbon dioxide were added to high-oleic canola oil in different concentrations (200, 500 and 750 mg/kg). After 30 h of deep-fat frying, oils fortified with canolol-enriched extracts showed a two to three times better frying performance in comparison to the commonly used antioxidants (TBHQ, 200 mg/kg; rosemary extract, 40 and 200 mg/kg) and a control without antioxidants with regards to the formation of di- and polymer triacylglycerols, total polar compounds, secondary degradation products (anisidine value) and the iodine value. The canolol-enriched extracts were also able to slow down the degradation of α- and γ -tocopherol during frying resulting in significant amounts of tocopherols after 30 h of frying in comparison to the other oils. The influence of the canolol-enriched extracts indicated strongly concentration-dependent performance. With increasing concentration of the extract, the thermal stability of the fortified oil was improved.