TY - JOUR
T1 - Enzymatic hydrolysis and fermentation of soy flour to produce ethanol and soy protein concentrate with increased polyphenols
AU - Agrawal, Ruchir M.
AU - Miller, Michael J.
AU - Singh, Vijay
AU - Stein, Hans H.
AU - Takhar, Pawan S.
N1 - Funding Information:
The authors thank USDA-NIFA for providing partial financial support under the award number ILLU-698-308. The authors also thank Maharashtra Oil Extraction Pvt. Ltd. and Archer Daniel Midlands Company for providing partial financial support and material support, respectively. Finally, the authors are grateful to Dr Yong-Su Jin and Dr Juan E. Andrade for their help with conducting tests.
Funding Information:
The authors thank USDA‐NIFA for providing partial financial support under the award number ILLU‐698‐308. The authors also thank Maharashtra Oil Extraction Pvt. Ltd. and Archer Daniel Midlands Company for providing partial financial support and material support, respectively. Finally, the authors are grateful to Dr Yong‐Su Jin and Dr Juan E. Andrade for their help with conducting tests.
Publisher Copyright:
© 2022 AOCS.
PY - 2022/5
Y1 - 2022/5
N2 - There is a need to effectively concentrate soy protein from defatted soy flour (DSF) while simultaneously valorizing the carbohydrate-rich byproduct, which would otherwise be a waste. This study aims to evaluate a process developed to produce soy protein concentrates (SPC) by substantially hydrolyzing carbohydrates from DSF with the help of enzymes into water-soluble saccharides and monomeric sugars, which were simultaneously utilized by Saccharomyces cerevisiae for fermentation into ethanol. The enzyme mixture consisted of cellulase, pectinase, and (Formula presented.) -galactosidase blend. The effect of process time on SPC, overall protein recovery, carbohydrate hydrolysis, yeast growth, ethanol concentration, and total polyphenol concentration (TPC) of SPC and hydrolysate was evaluated. Control and enzymes-only (EO) systems were maintained in conjunction with the enzymes + yeast (EY) system to individually assess the impact of isoelectric precipitation of soy proteins and enzymatic hydrolysis of carbohydrates without yeasts. After 12.25 h of EY process, 100 g of dry DSF produced 68.45 g dry SPC containing (Formula presented.) % protein and 384 ml hydrolysate containing (Formula presented.) mg/ml ethanol. Flatulence-causing raffinose-series-oligosaccharides (RSOs) were completely hydrolyzed. Soluble carbohydrates in the EY treatment were consistently lower than in the control and EO treatment. TPC of SPC prepared by EY treatment increased by 2.5 times compared to the control. Thus, this novel process successfully produced a high-protein SPC with hydrolyzed RSOs, lower insoluble carbohydrates, high TPC, and a coproduct ethanol.
AB - There is a need to effectively concentrate soy protein from defatted soy flour (DSF) while simultaneously valorizing the carbohydrate-rich byproduct, which would otherwise be a waste. This study aims to evaluate a process developed to produce soy protein concentrates (SPC) by substantially hydrolyzing carbohydrates from DSF with the help of enzymes into water-soluble saccharides and monomeric sugars, which were simultaneously utilized by Saccharomyces cerevisiae for fermentation into ethanol. The enzyme mixture consisted of cellulase, pectinase, and (Formula presented.) -galactosidase blend. The effect of process time on SPC, overall protein recovery, carbohydrate hydrolysis, yeast growth, ethanol concentration, and total polyphenol concentration (TPC) of SPC and hydrolysate was evaluated. Control and enzymes-only (EO) systems were maintained in conjunction with the enzymes + yeast (EY) system to individually assess the impact of isoelectric precipitation of soy proteins and enzymatic hydrolysis of carbohydrates without yeasts. After 12.25 h of EY process, 100 g of dry DSF produced 68.45 g dry SPC containing (Formula presented.) % protein and 384 ml hydrolysate containing (Formula presented.) mg/ml ethanol. Flatulence-causing raffinose-series-oligosaccharides (RSOs) were completely hydrolyzed. Soluble carbohydrates in the EY treatment were consistently lower than in the control and EO treatment. TPC of SPC prepared by EY treatment increased by 2.5 times compared to the control. Thus, this novel process successfully produced a high-protein SPC with hydrolyzed RSOs, lower insoluble carbohydrates, high TPC, and a coproduct ethanol.
KW - enzymatic hydrolysis
KW - ethanol
KW - fermentation
KW - raffinose
KW - soy protein concentrate
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UR - http://www.scopus.com/inward/citedby.url?scp=85122784866&partnerID=8YFLogxK
U2 - 10.1002/aocs.12573
DO - 10.1002/aocs.12573
M3 - Article
AN - SCOPUS:85122784866
SN - 0003-021X
VL - 99
SP - 379
EP - 391
JO - JAOCS, Journal of the American Oil Chemists' Society
JF - JAOCS, Journal of the American Oil Chemists' Society
IS - 5
ER -