Value-Added Potential of Expeller-Pressed Canola Oil Refining: Characterization of Sinapic Acid Derivatives and Tocopherols from Byproducts

Valuable phenolic antioxidants are lost during oil refining, but evaluation of their occurrence in refining byproducts is lacking. Rapeseed and canola oil are both rich sources of sinapic acid derivatives and tocopherols in commercially produced expeller-pressed canola oils subjected to various refining steps and the respective byproducts were investigates Loss of canolol (3) and tocopherols were observed during bleaching (84.9%) and deodorization (37.6%), respectively. sinapic acid (2) (42.9 mu g/g), sinapine (1) (199 mu g/g), and canolol (344 mu g/g) were found in the refining byproducts, namely, soap stock, spent bleaching clay, and wash water, for the first time Tocopherols (3.75 mg/g) and other nonidentified phenolic compounds (2.7 mg sinapic acid equivalent/g) were found in deodistillates, a byproduct of deodorization. DPPH radical scaenging confirmed the antioxidant potential of the byproducts This study confirms the value-added potential of byproducts of refining as sources of endogenous phenolics.