foods Article Different Processing Practices and the Frying Life of Refined Canola Oil Randy Adjonu 1,2,* , Zhongkai Zhou 1,3,4, Paul D. Prenzler 1,2 , Jamie Ayton 5 and Christopher L. Blanchard 1,2 1 ARC Industrial Transformation Training Centre for Functional Grains, Charles Sturt University, Wagga Wagga, NSW 2650, Australia;
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[email protected] (C.L.B.) 2 Graham Centre for Agricultural Innovations, Charles Sturt University, Wagga Wagga, NSW 2650, Australia 3 Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin 300457, China 4 School of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China 5 NSW Department of Primary Industries, Wagga Wagga Agriculture Institute, Wagga Wagga, NSW 2650, Australia;
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[email protected]; Tel.: +61-2-6933-2339 Received: 9 October 2019; Accepted: 21 October 2019; Published: 24 October 2019 Abstract: Refined expeller-pressed (RCanO-I and RCanO-II) and expeller-pressed and solvent-extracted blended (RCanO-III and RCanO-IV) canola oils were compared to determine the effect of processing (extraction) practice on the frying life of canola oil. Samples were from the 2016/2017 and 2017/2018 production seasons and were used to fry potato chips for 36 to 48 cycles. Frying life was assessed by the total polar compounds, retention of tocopherols, antioxidant activity, and other quality indices. RCanO-II exhibited significantly, the longest frying life as compared with the other three oils and this correlated with tocopherol retention and antioxidant activity (p < 0.05).