Recycling of Aqueous Supernatants in Soybean Oleosome Isolation

Oleosome extractions from soybean flour typically generate significant quantities of aqueous sucrose- and sodium chloride-rich supernatant which could be recycled. To determine the feasibility of recycling the oleosome process aqueous supernatants, three extraction protocols were evaluated. The first extraction used the original extraction solution, 0.1 M fresh potassium acetate pH 4.6 containing 0.4 M sucrose and 0.5 M NaCl. The second protocol reused the aqueous supernatant obtained from the first extraction. The third protocol reused the aqueous supernatant obtained from the second protocol. Oleosome extraction yields were significantly higher in the first extraction with enzymes (Multifect(A (R)) Pectinase FE, Multifect(A (R)) GC, and Multifect(A (R)) CX B, 1% each, v/w) compared to the yield when the supernatant was reused with no additional enzymes (81.41 +/- A 2.24 vs. 73.09 +/- A 3.39%, respectively). Oil yields from oleosome fractions were not statistically different when extractions were made with 0 or 3% enzymes in the third protocol. Protein was the predominant constituent in the supernatant in addition to mineral and carbohydrate. Soybean storage protein profile from recycled supernatants obtained without adding enzyme were similar to a traditional soy protein water extract but with a decrease of intensity of the beta-conglycinin bands. Addition of 3% enzymes in both recycling protocols resulted in the disappearance of the alpha' and alpha subunits of the beta-conglycinin due to a protease contaminant in Multifect(A (R)) Pectinase FE. Results from this work revealed essential information for a promising possibility of the future industrial application of this technology.