Effects of microwave-vacuum pre-treatment with different power levels on the structural and emulsifying properties of lotus seed protein isolates. (1st May 2020)

• Record Type: Journal Article
• Authors: Zheng, Yimei; Li, Zhiyu; Zhang, Chong; Zheng, Baodong; Tian, Yuting
• Is Part Of: Food chemistry. Volume 311(2020)
• Publication Date: 2020-05-01
• Subjects: Lotus seed protein isolates -- Microwave-vacuum treatment -- Structural properties -- Emulsifying ability; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2019.125932
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: MV treatment induced varying degrees of LSPIs unfolding with a decrease of α-helix. Highly-ordered LSPIs were dissociated under a moderate microwave-vacuum field. LSPIs treated by MV-100 W had the highest solubility and smallest protein size. Low power (50–100 W) MV treatment improved the emulsifying properties of LISPs. Abstract: The present study investigated the changes in structural and emulsifying properties of lotus seed protein isolates (LSPIs) under different microwave-vacuum (MV) treatments. A decrease of fluorescence peak intensity with blue-shift of the fluorescence emission maximum indicated that MV treatment induced unfolding of LSPIs so that more hydrophobic residues were exposed. Raman spectra showed that the ordered secondary structures (α-helix, β-sheet) gradually converted into β-turns and random coils during 50–150 W MV treatment. Particle size distribution and atomic force microscope revealed that the amounts of small subunits increased when the LSPIs were modified by 50–100 W MV treatment. Emulsions prepared by 100-W-MV-LSPIs exhibited the optimal emulsifying ability with the smallest oil droplet sizes. Confocal laser scanning microscopy and analytical centrifugal analyzer further proved 50–100 W MV-treatment enhanced the flocculation and creaming stability. Our findings provide a certain theoretical foundation to apply MV technology for developing desirable LSPIs-stabilized emulsions.