Recycling of Aqueous Supernatants in Soybean Oleosome Isolation

Abstract

Oleosome extractions from soybean flour typically generate significant quantities of aqueous sucroseand 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 Ò Pectinase FE, Multifect Ò GC, and Multifect Ò CX B, 1% each, v/w) compared to the yield when the supernatant was reused with no additional enzymes (81.41 ± 2.24 vs. 73.09 ± 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 b-conglycinin bands. Addition of 3% enzymes in both recycling protocols resulted in the disappearance of the a 0 and a subunits of the b-conglycinin due to a protease contaminant in Multifect Ò Pectinase FE. Results from this work revealed essential information for a promising possibility of the future industrial application of this technology.

Pilot Plant Recovery of Soybean Oleosome Fractions by an Enzyme‐Assisted Aqueous Process

“…Most of glycinin and b-conglycinin from whole seed were recovered in the supernatant as presented in Tables 1 and 2. These data are in accordance with our previous report on recycling of aqueous supernatants in soybean oleosome fractionation [28]. The glycinin and b-conglycinin represented 7-10 and 6-9% of the total oleosome mass.…”

“…Most of the a 0 subunit of b-conglycinin disappears while new peptide bands were observed at 23 kDa and minor bands at 6.5 kDa. These results indicated that the protease activity was present in the Multifect pectinase FE as we have reported previously [28]. In fact, when a protease inhibitor cocktail for yeast and fungi proteases was included in the oleosome extraction protocol [28], the a 0 , a subunits of the b-conglycinin and lipoxygenase were still present.…”

“…These results indicated that the protease activity was present in the Multifect pectinase FE as we have reported previously [28]. In fact, when a protease inhibitor cocktail for yeast and fungi proteases was included in the oleosome extraction protocol [28], the a 0 , a subunits of the b-conglycinin and lipoxygenase were still present. However, the protease in the commercial pectinase was necessary for oleosome fractionation since we obtained very low yields of intact oleosomes in the presence of the protease inhibitor or if we substituted a highly purified pectinase for Multifect pectinase FE (data not shown).…”

“…These results demonstrate that the scale-up of our oleosome fractionation process does not affect the protein profiles of oleosome and supernatant fractions [28]. Additionally, we have shown that the soybean storage proteins can be recovered in good yield from the supernatant of our scale-up process [28].…”

“…These results demonstrate that the scale-up of our oleosome fractionation process does not affect the protein profiles of oleosome and supernatant fractions [28]. Additionally, we have shown that the soybean storage proteins can be recovered in good yield from the supernatant of our scale-up process [28]. Although the protein profile from oleosome and supernatant fractions from the pilot or laboratory-scale processes were similar, the distribution of the protein in these fractions is significantly different (a = 0.05) ( Table 5).…”