The aim of this study was to explore the effect of atmospheric pressure plasma jet (APPJ) on the physicochemical, functional, and antioxidant properties of flaxseed protein following APPJ treatment (0 to 240 s). The results showed that the pH value continuously dropped with the minimum value of 3.45 ± 0.15 after 240 s of APPJ treatment (–61.7%, P < 0.05). The relative protein solubility significantly declined after 15 s of APPJ treatment (–43.1%, P < 0.05), which was accompanied by the evident increase in mean particle size of flaxseed protein in aqueous solution (+157%, P < 0.05). Moreover, the surface hydrophobicity and contents of disulfide bonds gradually raised when the APPJ exposure time extended from 30 to 240 s. Notably, the foaming, emulsifying, and in vitro antioxidant properties of flaxseed protein were significantly improved following short time of APPJ treatment (5 to 15 s), which was paralleled with the changes of spatial conformation, mild protein oxidation, as well as the release of phenolic acids and flavonoids from naturally occurring protein–phenolic complex. Our findings elucidated that APPJ may be considered as an effective strategy to improve the functionality and antioxidant activities of flaxseed protein.Practical ApplicationWe had evaluated the effect of APPJ treatment on the physicochemical, functional, and antioxidant properties of flaxseed protein, which was conducive to tailor flaxseed protein with the optimal techno‐functionality and antioxidant activities as a potential nano‐delivery vehicle.

No abstract

No abstract

BACKGROUND:The relatively inferior techno-functionality of flaxseed protein/polysaccharide complexes, especially regarding emulsifying and antioxidant activities, has partially limited their implication in the health food system. The present study aimed to investigate the effects of an atmospheric pressure plasma jet (APPJ) on the physicochemical, structural and selected techno-functional properties of flaxseed extracts. RESULTS:The results obtained showed that the full-fat and defatted flaxseed extract solutions (5 mg mL -1 ) displayed a sustainable decline in pH (−54.06%, −48.80%, P < 0.05) and zeta potential values (−29.42%, −44.28%, P < 0.05), but a gradual increase in particle sizes, as visualised by an optical microscope, during 0-120 s of APPJ treatment. Moreover, the APPJ led to initial decrease but subsequent increase in protein carbonyls and secondary lipid oxidation products, and concurrently changed the spatial conformation and microstructure of flaxseed extracts, as indicated by endogenous fluorescence properties and scanning electron microscopy (SEM). Additionally, the protein subunit remodeling and gum polysaccharides depolymerization were different for full-fat and defatted flaxseed extracts after 30 s of APPJ exposure. Importantly, the emulsifying and antioxidant activities of defatted flaxseed extract were particularly improved, as assessed by cyro-SEM and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity following 15-30 s of APPJ treatment, as a result of the changing interactions between protein and gum polysaccharides, as well as the release of specific phenolic compounds.CONCLUSION: APPJ could serve as a promising strategy for tailoring the specific techno-functionality of flaxseed extracts based on mild structural modification.

This is an open access article under the terms of the Creat ive Commo ns Attri bution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.