Lunasin and Bowman-Birk Protease Inhibitor Concentrations of Protein Extracts from Enzyme-Assisted Aqueous Extraction of Soybeans

Thumbnail Image
Supplemental Files
Date
2011-05-31
Authors
Nobrega de Moura, Juliana Maria
Hernandez-Ledesma, Blanca
de Almeida, Neiva
Hsieh, Chia-Chien
de Lumen, Ben
Major Professor
Advisor
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract

Lunasin and Bowman-Birk protease inhibitor (BBI) are two soybean peptides to which health-promoting properties have been attributed. Concentrations of these peptides were determined in skim fractions produced by enzyme-assisted aqueous extraction processing (EAEP) of extruded full-fat soybean flakes (an alternative to extracting oil from soybeans with hexane) and compared with similar extracts from hexane-defatted soybean meal. Oil and protein were extracted by using countercurrent twostage EAEP of soybeans at 1:6 solids-to-liquid ratio, 50C, pH 9.0, and 120 rpm for 1 h. Protein-rich skim fractions were produced from extruded full-fat soybean flakes using different enzyme strategies in EAEP: 0.5% protease (wt/g extruded flakes) used in both extraction stages; 0.5% protease used only in the second extraction stage; no enzyme used in either extraction stage. Countercurrent two-stage protein extraction of air-desolventized, hexane-defatted soybean flakes was used as a control. Protein extraction yields increased from 66% to 89-96% when using countercurrent two-stage EAEP with extruded full-fat flakes compared to 85% when using countercurrent two-stage protein extraction of air-desolventized, hexane-defatted soybean flakes. Extruding full-fat soybean flakes reduced BBI activity. Enzymatic hydrolysis reduced BBI contents of EAEP skims. Lunasin, however, was more resistant to both enzymatic hydrolysis and heat denaturation. Although using enzymes in both EAEP extraction stages yielded the highest protein and oil extractions, reducing enzyme use to only the second stage preserved much of the BBI and Lunasin.

Series Number
Journal Issue
Is Version Of
Versions
Series
Type
article
Comments

Reprinted with permission from Journal of Agricultural and Food Chemistry 59(13): 6940-6946. doi: 10.1021/jf200183m. Copyright 2011 American Chemical Society.

Rights Statement
Copyright
Sat Jan 01 00:00:00 UTC 2011
Funding
DOI
Supplemental Resources
Collections