title: Structural changes in natural actomyosin and surimi from ling cod (Ophiodon elongatus) during frozen storage in the absence or presence of cryoprotectants.
abstract: Surimi and natural actomyosin (NAM) from ling cod (Ophiodon elongatus) were subjected to frozen storage in the absence or presence of cryoprotectants (sorbitol, sucrose, lactitol, and Litesse, either individually or in combination). Effects of frozen storage were studied for NAM frozen at -10 degrees C for 10 days and for surimi after eight freeze-thaw cycles. A commercial blend cryoprotectant (4% sucrose and 4% sorbitol), individual cryoprotectants at 8%, and optimal blends at 4, 5.5, 6, and 8%, were effective in maintaining the gel strength of surimi and NAM gels. Surimi or NAM frozen in the absence of cryoprotectants or with only 4% individual cryoprotectants, showed increased percent alpha-helical content by Raman analysis. Increased disulfide content was also observed in the treatment without cryoprotectants by the Raman SS stretching band and by chemical determination. Tyrosine residues were in a buried environment before and after freezing for all treatments, and surface hydrophobicity measured by 1-anilinonaphthalene-8-sulfonate decreased after frozen storage in the absence of cryoprotectants.
authors.affiliation: Faculty of Agricultural Sciences, Food, Nutrition and Health Program, The University of British Columbia, Food Science Building, 6650 Northwest Marine Drive, Vancouver, British Columbia, Canada V6T 1Z4.
authors.forename: Y
authors.initials: Y
authors.lastname: Sultanbawa
authors.forename: E C
authors.initials: EC
authors.lastname: Li-Chan
mesh_terms: D000205:Actomyosin / Q000737:chemistry*; D000818:Animals; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003451:Cryoprotective Agents / Q000494:pharmacology*; D004220:Disulfides / Q000737:chemistry; D005396:Fish Products / Q000032:analysis*; D005399:Fishes; D005628:Frozen Foods; D005782:Gels; D057927:Hydrophobic and Hydrophilic Interactions; D011506:Proteins / Q000032:analysis; D013059:Spectrum Analysis, Raman; D013438:Sulfhydryl Compounds / Q000032:analysis; D014867:Water
chemical_list: D003451:Cryoprotective Agents; D004220:Disulfides; D005782:Gels; D011506:Proteins; D013438:Sulfhydryl Compounds; D014867:Water; D000205:Actomyosin