Preparation and Physico-Chemical Characterization of OSA-Modified Starches from Different Botanical Origins and Study on the Properties of Pickering Emulsions Stabilized by These Starches

Abstract

Native starch (NS) from different botanical origins (native rice/tapioca/oat starch, NRS/NTS/NOS) were hydrophobically modified by octenyl succinic anhydride (OSA), and the octenyl succinic (OS) groups were successfully introduced in the starch molecules which obtained OS-starch (OSRS, OSTS and OSOS) with different levels of modification (0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%) and degree of substitution (DS). The structural properties of the OS-starch, such as granule size, crystal, wettability and morphology were studied, and the OS-starch was used as particulate stabilizers to produce oil-in-water (O/W) Pickering emulsions. The emulsion index, droplet size distribution and microstructures of Pickering emulsions produced by different OS-starches were compared. OSA modification had almost no effect on the morphology or crystal structure types of three kinds of NS and OS-starch but markedly increased the contact angle and particle size distribution of OSRS, OSTS and OSOS. Esterification reaction of OSA and starch mainly occurred in amorphous regions of starch, and the OSA significantly improved the emulsifying capacity of OSRS, OSTS and OSOS granules and thus stabilized emulsions formed at higher levels (2.5% and 3.0%) of modification of OS-Starch exhibited better stability; the ability of OS-starch to stabilize Pickering emulsion was 3.0% OSRS > 3.0% OSOS > 3.0% OSTS, respectively. Observation and structural properties analysis of OS-starch granules and Pickering emulsion droplets showed that the number and thickness of the starch granules on the oil-water interface of the emulsion droplets increased with improvement of the OSA modification level, and an aggregation state was formed between the OS-starch granules, which was also enhanced with the OSA modification levels. These were all necessary for the Pickering emulsion stabilized by starch granules to remain in a steady state.

The Preparation of Curcumin-Loaded Pickering Emulsion Using Gelatin–Chitosan Colloidal Particles as Emulsifier for Possible Application as a Bio-Inspired Cosmetic Formulation

“…Accordingly, finding an appropriate, safe, sustainable, and effective bio-based natural emulsifier must be prioritized. Recently, a select few bio-compatible macromolecules, like chitosan aggregates, cellulose nanocrystals, egg granules, and starch granules, have been explored as green emulsifiers [ 19 , 20 , 21 ]. Compared with other biopolymers, protein particles are better emulsifiers due to the fact that the hydrophilicity of their surfaces can be tuned via modulating electrostatic charge.…”

Improved Viability of Probiotics via Microencapsulation in Whey-Protein-Isolate-Octenyl-Succinic-Anhydride-Starch-Complex Coacervates

“…Octenyl succinic anhydride (OSA) starch, i.e., starch modified with OSA groups (an esterifying agent), has been recognised as a safe polysaccharide by the United States Food and Drug Administration (FDA) [7,14]. The hydrophobicity of OSA starch is relatively high with a contact angle of about 80 • due to the presence of lipophilic octenyl groups [15,16]. In addition, the digestibility of OSA starch was relatively low due to the spatial obstruction caused by the OSA groups, which reduces its contact with digestive enzymes [17].…”