Efficacy of green processing techniques on the recovery of phenolic compounds from canola meal

• Published in: Applied Food Research
• Main Authors: Olamide S. Fadairo, Ruchira Nandasiri, Soleiman Abbasi, N.A. Michael Eskin, Rotimi E. Aluko, Martin G. Scanlon
• Format: Article
• Language: English
• Published: Elsevier 2025-06-01
• Subjects: Green extraction; Supercritical CO2 extraction; Microemulsion extraction; Canola; phenolic antioxidants
• Online Access: http://www.sciencedirect.com/science/article/pii/S2772502225002847

The current study investigated how supercritical CO2 (SCCO2) and micro-emulsion techniques (MT) used as green processing methods for the extraction of oil from canola press cake affected availability of phenolics from canola (Brassica napus). Canola press cakes obtained from expeller-pressed canola seeds at 60 ℃ from two different sources were subjected to various SCCO2 and MT protocols. The resultant partially defatted meals obtained from SCCO2 with various levels of residual oil and from MT had their phenolics extracted using ultrasound-assisted extraction (UAE). The phenolic-rich extracts were analysed and quantified by HPLC-DAD. The antioxidant potential of the extracts was also evaluated using in-vitro antioxidant assays (DPPH radical scavenging, metal ion chelation, and ferric reducing power). Results were compared with extracts from de-oiled canola meal prepared by solvent extraction. The results showed that MT defatted meal resulted in the lowest amount of sinapine (219 ± 5 µg/g DW) (M2) while SCCO2 defatted meal showed better total phenolic contents (4.65 ± 0.19 mg GAE/g) compared to MT (M2) (0.30 ± 0.04 mg GAE/g). The results of antioxidant activity indicated that extracts from MT defatted meal exhibited the highest metal chelating capacity (75.5 %) while extracts from SCCO2 defatted meals generally showed increased potential for scavenging the DPPH free radical and reducing the ferric ion to the stable ferrous ion, both different aspects of lipid peroxidation. These findings provide insights on the use of green technologies that will enhance the utilization of canola meal protein for food applications.