Alkylsuccinylated oxidized cellulose-based amphiphiles as a novel multi-purpose ingredient for stabilizing O/W emulsions

Abstract

A novel type of emulsifiers (STOC- SAC0, SAC8 & SAC12) were synthesized from nature-abundant cellulose by a two-step process: preparartion of soluble cellulose by TEMPO-mediated oxidation of cellulosic nanocrystal and fractionation (STOC), and introduction of hydrophobic moiety by alkyl (C0, C8 & C12)succinylation of resulting soluble polysaccharides. The synthetic products were structurally verified by Fourier Transform Infrared (FT-IR), Nuclear Magnetic Resonance (NMR) and Gel Permeation Chromatography (GPC). The surface-active property and functionality of the new ingredients were characterized by determinations of contact angle, ABTS radical scavenging and Ferrous chelating ability, and their performance as new ingredient; which demonstrated that alkylsuccinylated soluble TEMPO-oxidized celluloses (STOC-SAC x ) have unique multi-purpose functionalities: emulsifying, stabilizing and antioxidant property. STOC-SAC12 displayed the best surface activity with the lowest contact angle (18° on a hydrophobic surface basis) and the highest antioxidant properties (compared to succinylated cellulose (C-SAC0) the ABTS radical scavenging and Fe 2+ chelating property of STOC-SAC12 are significantly higher by 10-fold and 4.5-fold, respectively); accordingly STOC-SAC12 also resulted in the most stable homogeneous fish oil-in-water nanoemulsion with a mean droplet size of 200 nm, polydispersity index of 0.18 and ζ-potential up to −90 mV; evidenced by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLFM) and dynamic light scattering analyses. In short this work reported a industry-feasible and fully scalable approach to transform abundant renewable plant cellulose into novel ingredients with unique fucntionalities which could find potential application in delivery of oxidation-prone bioactives through complicated emulsion systems. • Alkyl (C 0 , C 8 , C 12 )succinylation endowed cellulose/Soluble TEMPO-Mediated Oxidized Celluloses (STOC) with various surface-active properties. • Successful alkylsuccinylation of cellulose/STOC were confirmed by FTIR, NMR (GPC analysis for STOC). • STOC-SAC12 demonstrated excellent multi-purpose functionalities as emulsifier, stabilizer and antioxidant. • Compared to C-SAC0 the ABTS radical scavenging and Fe 2+ chelating property of STOC-SAC12 are 10-fold and 4.5-fold higher.