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

Fengchao Zhou; Mingyang Dong; Jianhui Huang; Guorong Lin; Jie Liang; Shibin Deng; Chenqi Gu; Qingyu Yang

doi:10.3390/polym15030706

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

Polymers (Basel). 2023 Jan 31;15(3):706. doi: 10.3390/polym15030706.

Authors

Fengchao Zhou¹, Mingyang Dong², Jianhui Huang¹, Guorong Lin¹, Jie Liang¹, Shibin Deng¹, Chenqi Gu², Qingyu Yang²

Affiliations

¹ Fujian Provincial Key Laboratory of Ecology-Toxicological Effects & Control for Emerging Contaminants, College of Environmental and Biological Technology, Putian University, Putian 351100, China.
² College of Grain Science and Technology, Shenyang Normal University, Shenyang 110034, China.

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.

Keywords: OSA; Pickering emulsions; oat starch; rice starch; stability; tapioca starch.

Grants and funding

This research was funded by the Fujian Provincial Natural Science Foundation of China (2020J01913) and by grants from the National key R&D Plan in the 14th five-year plan (2021YFD1600604). The study was also supported by Putian University introduced talent scientific research launch fund project (2019004).