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

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 hexanedefatted 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. 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, 50°C, 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 89À96% 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 ...

Probing the Soybean Bowman–Birk Inhibitor Using Recombinant Antibody Fragments

“…Surprisingly, the advancement of recombinant antibody technology is under-represented in food research and industry, an area where there is a need for improved analytical and purification methodologies. 22,31 Just as soy consumption patterns vary greatly across the world, so too do cancer incidences. An inverse relationship between soybean intake and cancer incidence has been reported, with Asian countries where soy forms an important part of the diet, such as Japan, displaying the lowest incidences of cancer.…”

“…The propensity for BBI to self-associate has previously been observed by us and others, with or without SDS, and in the presence of β-mercaptoethanol and urea. 3,9,31 After separation on the SDS-PAGE gel, proteins immunoprecipitated by magnetic particles were then analyzed by direct tandem mass spectrometry after in-gel digestion with trypsin and reversephase separation of the tryptic peptides. The prominent band was identified as the soybean trypsin inhibitor (Figure 6b).…”

“…Minor modifications have been proposed, 30 but the BBI isolation process remains challenging. 3,31 In the present study, we have cloned VH and VL domains from the hybridoma cell mAb 238 and assembled them together as single-chain Fv (scFv) and diabody (scDb) molecules. Recombinant antibody fragments were bacterially expressed in Escherichia coli cells and purified at a level of ∼500 μg L −1 of culture.…”

Aqueous and Enzymatic Extraction of Oil and Protein from Almond Cake: A Comparative Study

“…As described in the AEP section, the comparison of our results with the literature is challenging due to the lack of studies reporting oil and protein extraction yields from partially defatted almond cake produced by mechanical pressing. For example, while oil extraction yields ranging from 75-78% have been reported for the EAEP of full-fat almond flour [12,53], no protein extraction yields were reported for both studies. Because of the difference in the starting material used (full fat almond flour vs. partially defatted almond cake), a direct comparison of the results from both studies is difficult.…”

Discovery of lunasin peptide in triticale (X Triticosecale Wittmack)

“…Moreover, studies in animals showed that lunasin can be administered orally and can enter target tissues (de Lumen, 2005). Findings that lunasin is bioavailable, bioactive and thermostable after administration provided the basis for recommendations of the inclusion of lunasin-containing products in regular human diets (Leite Nobrega de Moura et al, 2011;Park et al, 2007;Jeong et al, 2010).…”