Table 3 Antioxidant potential of flaxseed cake
Component | Antioxidant Assessment Method | Major findings | References |
|---|---|---|---|
Defatted flaxseed extracts Non- Defatted flaxseed extracts | DPPH FRAP | -DPPH radical levels ranged from 19.7 to 76.1% and 28.7–76.3% for defatted and non-defatted flaxseed extracts respectively. -Non-defatted extracts had higher scavenging activity The DPPH scavenging activity increased with extract concentration. -The FRAP values for defatted and non-defatted flaxseed extracts were found to be 0.058 and 0.062 mmol TE/g, respectively. Non-defatted extracts showed lower ferric reducing capacity The antioxidants in flaxseed oil lowers DPPH capacity of defatted flaxseed | Brodowska et al. (2014) |
Flaxseed cake extract | β- carotene coupled oxidation DPPH Reducing antioxidant BHT was used as a control. | -The β-carotene coupled oxidation value (73.52%), DPPH value (55.28%), and reducing antioxidant value (4240 µg/g) of flaxseed cake extract strongly suggest its antioxidant power. -For β-carotene coupled oxidation and DPPH when compared to BHT (82.91% and 61.72%), the value of the extract is slightly lower. For reducing antioxidants, the value for flaxseed extract was found to be significantly lower. | Akl et al. (2020) |
Flaxseed extracts (from different varieties) | DPPH(g/L) ABTS (mmol Trolox/g) FRAP (mmol FeSO4 /g) Chelating activity (g/L) | -The ethanolic extracts contained 6–11 times higher phenolics when compared to the aqueous extracts. The ethanolic extraction is more selective than aqueous extraction for phenolic compounds. A similar trend was found in the case of DPPH and ABTS assays as ethanolic extracts were 5-8.5 and 7.5-9 times higher than the aqueous extracts, respectively. -The difference in the values of different extracts is due to the contents of phenolics. | Waszkowiak et al. (2015) |
Flaxseed cake extracts from- Hot-pressed cake (HPC) Cold-pressed cake (CPC) n-Hexane cake (HC) Supercritical CO2 cake (SCC) Subcritical n-butane cake (SBC) | DPPH FRAP ABTS Reducing power | -The DDPH scavenging activity of HPC was found to be highest followed by CPC, SCC, SBC, and HC. Bound phenolics are generally released upon heating which justifies the highest value of HPC. Also, the DPPH scavenging activity of pressed cake extract was twice as compared to solvent-extracted cakes. -The FRAP values were in a sequence of highest to lowest as-HPC followed by SCC, SBC, CPC, and HC. The higher the FRAP value, the higher the antioxidant capacity. FRAP values of press cakes were higher than solvent-extracted cakes. -HPC showed the highest values for scavenging ABTS free radicals. -HPC extract showed the highest total reducing power. The extracts of pressed cakes possess reducing agents when compared to solvent-extracted cakes. | |
Flaxseed cake(FSM) extract Flaxseed cake extract | DPPH (mmol TE/g) ABTS (mmol TE/g) FRAP (mmol TE/g) DPPH | -Methanol (high polarity) and ethyl acetate (low polarity) were used as solvent for extraction. The value of DPPH for methanolic extracts of FSM is three-fold higher than the ethyl acetate extracts. ABTS values of methanolic extracts of FSM were twice as compared to flaxseed. -For flaxseed cake, the FRAP value of methanolic extracts was eight times higher than that of ethyl acetate extracts. -Extracts made with 60% and 80% ethanol showed 21.22% and 72.95% scavenging activity whereas a 100% ethanolic extract showed ineffective results. Also, hydrolyzed extracts showed double values of scavenging activity due to the breakage of linkages and deglycosylation of phenolic compounds. Natural antioxidants and flaxseed cake extract showed comparable values for radical scavenging activities. | Quezada and Cherian (2012) Pag et al. (2014) |