Formation of soy protein isolate (SPI)-citrus pectin (CP) electrostatic complexes under a high-intensity ultrasonic field: Linking the enhanced emulsifying properties to physicochemical and structural properties

Xiaobin Ma; Tianyi Yan; Furong Hou; Weijun Chen; Song Miao; Donghong Liu

doi:10.1016/j.ultsonch.2019.104748

Formation of soy protein isolate (SPI)-citrus pectin (CP) electrostatic complexes under a high-intensity ultrasonic field: Linking the enhanced emulsifying properties to physicochemical and structural properties

Ultrason Sonochem. 2019 Dec:59:104748. doi: 10.1016/j.ultsonch.2019.104748. Epub 2019 Aug 23.

Authors

Xiaobin Ma¹, Tianyi Yan², Furong Hou², Weijun Chen², Song Miao³, Donghong Liu⁴

Affiliations

¹ College of Biosystems Engineering and Food Science, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang R & D Center for Food Technology and Equipment, Zhejiang University, Hangzhou 310058, China; Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland.
² College of Biosystems Engineering and Food Science, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang R & D Center for Food Technology and Equipment, Zhejiang University, Hangzhou 310058, China.
³ Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland; College of Biosystems Engineering and Food Science, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang R & D Center for Food Technology and Equipment, Zhejiang University, Hangzhou 310058, China. Electronic address: song.miao@teagasc.ie.
⁴ College of Biosystems Engineering and Food Science, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang R & D Center for Food Technology and Equipment, Zhejiang University, Hangzhou 310058, China; Fuli Institute of Food Science, Zhejiang University, Hangzhou 310058, China. Electronic address: dhliu@zju.edu.cn.

PMID: 31473418
DOI: 10.1016/j.ultsonch.2019.104748

Abstract

In this study, a high-intensity ultrasonic field was applied to the electrostatic interactions between soy protein isolate (SPI) and citrus pectin (CP). The emulsifying properties of SPI-CP soluble complexes formed under different ultrasound powers and durations were investigated and peaked at 630 W for 10 min. Micrographs of emulsions revealed that ultrasound-treated complexes generated a more homogeneous emulsion with significantly reduced and uniformly-distributed droplet sizes. To better understand the mechanism for the improved emulsifying properties, the physicochemical and structural properties of the SPI-CP complexes at pH 3.5 with and without ultrasound treatment were investigated. It was revealed that ultrasound increased the absolute values of the zeta potential and surface hydrophobicity of complexes, but significantly decreased their particle sizes, fluorescence intensity and turbidity. Results indicated that cavitation effects resulted in structural modifications in both biomacromolecules, as well as enhanced the electrostatic interactions between SPI and CP, which in combination contributed to the more desirable emulsifying properties of the complex.

Keywords: Electrostatic interaction; Emulsifying property; Physicochemical property; Soluble complex; Structural property; Ultrasound.