{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/23261"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/23261","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Enzymatic modification and fractionation of corn protein","abstract":"The overall objective of this research was to enhance the utilization of corn refining by-products by improving the functional properties of corn proteins.","abstract_html":"The overall objective of this research was to enhance the utilization of corn refining by-products by improving the functional properties of corn proteins.","abstract_has_math":false,"creators":["Mannheim, Adie"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Food Science and Human Nutrition","degree_department":null,"school":null,"contributors":["Cheryan, Munir"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T14:07:51Z","date_published":"2011-05-07T14:07:51Z","updated_at":"2026-07-22T22:25:21Z","subjects":["Agriculture, Food Science and Technology","Chemistry, Biochemistry"],"languages":["eng"],"rights":["Copyright 1991 Mannheim, Adie"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9234268","(UMI)AAI9234268"],"render_values":[{"text":"AAI9234268","href":null,"code":true},{"text":"(UMI)AAI9234268","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/23261","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Cheryan, Munir"]},{"key":"dc:creator","label":"Author","values":["Mannheim, Adie"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T14:07:51Z","10000-01-01","1991"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Food Science and Human Nutrition"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Agriculture, Food Science and Technology","Chemistry, Biochemistry"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1991 Mannheim, Adie"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9234268","(UMI)AAI9234268","http://hdl.handle.net/2142/23261"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The overall objective of this research was to enhance the utilization of corn refining by-products by improving the functional properties of corn proteins.","Methods were developed to modify zein and glutelin, present in corn gluten meal (CGM), using controlled enzymatic hydrolysis and membrane technology. Since zein is soluble only in organic solvents and glutelin in alkaline solutions, several enzymes were screened for their activity and stability in aqueous and organic solvents. Alcalase$\\sp\\circler$ (a serine endo-peptidase made from Bacillus licheniformis) was found suitable for this purpose.","Pre-treatment of CGM to reduce disulfide bonds present in its matrix, significantly improved hydrolysis rates. Sodium sulfite was found to be effective at 0.4 mg/mL. For zein hydrolysis, a two-phase sequential hydrolysis process was developed: the first reaction conducted in 60% isopropanol (37$\\sp\\circ$C, pH 9), followed by a second aqueous phase reaction at 50$\\sp\\circ$C and pH 9.","The modified and native corn proteins were fractionated using 10,000 and 30,000 molecular weight cut-off hollow fiber membranes. Almost all fractions showed two major peaks with size-exclusion HPLC: one at $>$70,000 daltons and another at 5,500 daltons. The smaller fraction was not affected by the degree of hydrolysis or membrane pore size.","Nitrogen solubility index (NSI) of CGM and zein increased dramatically by enzymatic treatment and membrane fractionation from an average of 8% in the unmodified protein to 99%, at a pH range of 3 to 9. NSI was also affected by degree of hydrolysis (DH) and membrane pore size, increasing with the former and decreasing with the latter.","Foam volume and stability increased with DH and pH. Membrane filtration of hydrolyzates decreased foam stability but increased foam volume.","Moisture sorption characteristics of corn protein hydrolyzates were superior to unmodified protein. At a water activity of 0.97, moisture sorption of sulfite-treated CGM (10% DH) was 380 gm water/100 gm solids, compared to 30 for the unmodified CGM. Values for zein (12-20% DH) were 275 and 245 gm water/100 gm solids, respectively.","Made available in DSpace on 2011-05-07T14:07:51Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9234268.pdf: 5464082 bytes, checksum: 2560b9b1bceebe90aa08d61c2e0a930a (MD5) Previous issue date: 1991","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T15:03:16Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:30:09-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"]},{"key":"dc:title","label":"Title","values":["Enzymatic modification and fractionation of corn protein"]}]}],"canonical_facts":{"dc:contributor":["Cheryan, Munir"],"dc:creator":["Mannheim, Adie"],"dc:date":["2011-05-07T14:07:51Z","10000-01-01","1991"],"dc:description":["The overall objective of this research was to enhance the utilization of corn refining by-products by improving the functional properties of corn proteins.","Methods were developed to modify zein and glutelin, present in corn gluten meal (CGM), using controlled enzymatic hydrolysis and membrane technology. Since zein is soluble only in organic solvents and glutelin in alkaline solutions, several enzymes were screened for their activity and stability in aqueous and organic solvents. Alcalase$\\sp\\circler$ (a serine endo-peptidase made from Bacillus licheniformis) was found suitable for this purpose.","Pre-treatment of CGM to reduce disulfide bonds present in its matrix, significantly improved hydrolysis rates. Sodium sulfite was found to be effective at 0.4 mg/mL. For zein hydrolysis, a two-phase sequential hydrolysis process was developed: the first reaction conducted in 60% isopropanol (37$\\sp\\circ$C, pH 9), followed by a second aqueous phase reaction at 50$\\sp\\circ$C and pH 9.","The modified and native corn proteins were fractionated using 10,000 and 30,000 molecular weight cut-off hollow fiber membranes. Almost all fractions showed two major peaks with size-exclusion HPLC: one at $>$70,000 daltons and another at 5,500 daltons. The smaller fraction was not affected by the degree of hydrolysis or membrane pore size.","Nitrogen solubility index (NSI) of CGM and zein increased dramatically by enzymatic treatment and membrane fractionation from an average of 8% in the unmodified protein to 99%, at a pH range of 3 to 9. NSI was also affected by degree of hydrolysis (DH) and membrane pore size, increasing with the former and decreasing with the latter.","Foam volume and stability increased with DH and pH. Membrane filtration of hydrolyzates decreased foam stability but increased foam volume.","Moisture sorption characteristics of corn protein hydrolyzates were superior to unmodified protein. At a water activity of 0.97, moisture sorption of sulfite-treated CGM (10% DH) was 380 gm water/100 gm solids, compared to 30 for the unmodified CGM. Values for zein (12-20% DH) were 275 and 245 gm water/100 gm solids, respectively.","Made available in DSpace on 2011-05-07T14:07:51Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9234268.pdf: 5464082 bytes, checksum: 2560b9b1bceebe90aa08d61c2e0a930a (MD5) Previous issue date: 1991","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T15:03:16Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:30:09-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"],"dc:identifier":["AAI9234268","(UMI)AAI9234268","http://hdl.handle.net/2142/23261"],"dc:language":["eng"],"dc:rights":["Copyright 1991 Mannheim, Adie"],"dc:subject":["Agriculture, Food Science and Technology","Chemistry, Biochemistry"],"dc:title":["Enzymatic modification and fractionation of corn protein"],"dc:type":["text"],"thesis:degree_discipline":["Food Science and Human Nutrition"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:21Z"}