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COTTONSEED PROTEIN MODIFICATION IN AN ULTRAFILTRATION CELL
Author(s) -
CUNNINGHAM S.D.,
CATER C.M.,
MATTIL K.F.
Publication year - 1978
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1978.tb02523.x
Subject(s) - hydrolysate , chromatography , chemistry , ultrafiltration (renal) , sodium dodecyl sulfate , hydrolysis , membrane , pepsin , enzymatic hydrolysis , centrifugation , enzyme , biochemistry
Cottonseed storage protein was modified by proteolytic enzymes contained within a semipermeable membrane reactor. An ultrafiltration cell was used as the enzyme reactor vessel. The protein was hydrolyzed by the enzyme and the resulting lower molecular weight peptides (modified protein or hydrolysate) were removed from the reactor through the membrane. Only about 2% of the original protein was removed through the membrane when no enzyme was present. When pepsin and molsin were added to the cell, protein hydrolysis occurred very rapidly. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) was used to monitor hydrolysis. The hydrolysate contained many peptides below 4,000 daltons. Addition of pepsin was shown to precipitate about 4% of the SP and the precipitated protein rapidly clogged the membrane and reduced membrane flux rate. The precipitated protein was insoluble except in strongly alkaline solutions but its formation was shown to be influenced by pH. Use of hollow fibers as the enzyme reactor increased membrane surface area and improved hydrolysate removal from the reactor. Centrifugation of the precipitate was unnecessary with hollow fibers because of the high velocity of retentate through the fibers.