Production and technological characteristics of avocado oil emulsions stabilized with cellulose nanofibrils isolated from agroindustrial residues

Abstract

The present work provided the valorization of agroindustrial residues from the palm peach (Bactris gasipaes) industry to produce cellulose nanofibrils (CNFs) and considered their application as a stabilizer agent for avocado oil emulsions. The treatments applied generated CNFs bundles with high aspect ratio, stability and mobility of (-) 19.82 ± 7.7 (μ/s)/(V/cm) at water suspensions; crystallinity index of 31.5 % and superficial functional groups (FT-IR spectra) that remarked them as able to interact with polar and non-polar molecules. The little amount of 1.0 % of CNF was able to stabilize emulsions with high oil content (50 %) that remained steady after 30 days of storage at different temperatures, probably by CNF’s Pickering-mechanism. Emulsions with sorbitan monostearate (3.5 %) were also produced and the replacement or interaction of this agent with CNF (0, 50 and 1.0 %) was evaluated by creaming behavior, stability index and morphological characterization. It was not observed a synergistic effect between the components; emulsions that contained only CNF (CNF 100) showed superior characteristics, with no creaming or coalescence at 02 and 25 °C for 30 days; no coalescence after thermal treatments (02 and 80 °C) associated with extreme pH variations (2 and 11) and lower droplets size. Besides address a practical application for nanocelluloses obtained from discarded lignocellulosic material, the results suggests the possibility of produce a potentially edible emulsion from an oil with high oleic acid content and bioactive molecules without the addition of any surfactant or other chemical additive, that could be used for new food, cosmetic or pharmaceutical applications.