Properties of protein isolates extracted by ultrasonication from soybean residue (okara)

Ogemdi F Eze; Afroditi Chatzifragkou; Dimitris Charalampopoulos

doi:10.1016/j.foodchem.2021.130837

Properties of protein isolates extracted by ultrasonication from soybean residue (okara)

Food Chem. 2022 Jan 30:368:130837. doi: 10.1016/j.foodchem.2021.130837. Epub 2021 Aug 10.

Authors

Ogemdi F Eze¹, Afroditi Chatzifragkou¹, Dimitris Charalampopoulos²

Affiliations

¹ Department of Food and Nutritional Sciences, University of Reading, Whiteknights, Reading RG6 6AP, UK.
² Department of Food and Nutritional Sciences, University of Reading, Whiteknights, Reading RG6 6AP, UK. Electronic address: d.charalampopoulos@reading.ac.uk.

PMID: 34419797
DOI: 10.1016/j.foodchem.2021.130837

Abstract

Soybean protein extraction was evaluated using conventional (alkaline phosphate buffer) and ultrasonication assisted methods. The impact of the extraction method on protein yield, chemical composition, and structural properties of the protein isolates was assessed. In conventional alkaline extraction, increasing pH values (from 9 to 12) led to an increase in the protein yield, with pH 12 favouring protein extraction, with yields up to 36 % (w/w). Ultrasonication process at the same pH, led to maximum protein extraction yield of 84 % (w/w). Secondary structural changes in ultrasonicated OPI samples were linked to cavitation effects and the duration of the extraction, rather than the intensity of ultrasonication process. Extracted proteins exhibited increased β-sheet content, improved zeta-potential and smaller particle size of ultrasonicated proteins, rendering them suitable ingredients for tailored food applications.

Keywords: Extraction; FTIR; Okara; Protein isolate; Soybeans; Ultrasonication.

MeSH terms

Glycine max*
Particle Size
Soybean Proteins*

Substances

Soybean Proteins