Dual-resource prioritisation of canola oil refining by-products for integrated valorisation strategies

This study evaluated industrial canola oil refining by-products from Australian chemical and physical refining plants to assess their potential for integrated valorisation through phytonutrient recovery combined with valorisation of the fatty acid-rich fraction. Tocopherols and phytosterols, representing the unsaponifiable fraction, were analysed using GC-QTOF-MS, while fatty acids, as the saponifiable fraction, were quantified using GC-FID. Compositional analysis confirmed that deodoriser distillates contained the highest phytonutrient fraction, with total tocopherols of ∼12.0-34.2 g/kg dw and total phytosterols of ∼24.7-77.4 g/kg dw, as well as considerable fatty acids (∼290-813 mg/g dw), ranking distillates as the most promising resource for integrated valorisation. Soapstock-gum presented intermediate potential, with ∼6.4-13.8 g/kg dw total phytosterols and ∼ 92-608 mg/g dw total fatty acids. In contrast, oils from spent bleaching earth were low in phytonutrients, but retained considerable levels of fatty acids, supporting their lipid-focused valorisation, while gum showed low potential for these valorisation routes.