title: FT-IR and Raman spectroscopies determine structural changes of tilapia fish protein isolate and surimi under different comminution conditions.
abstract: Tilapia proteins refined by pH shift and water washing were chopped under various comminution conditions and their structural changes were investigated using Fourier transform infrared (FT-IR) and Raman spectroscopies. Both techniques revealed the degree of unfolding in protein structure increased when fish protein isolate (FPI) and surimi were chopped at 25°C for 18min compared to samples chopped at 5°C for 6min. Results indicated both hydrophobic interactions and disulfide bonds were significantly enhanced during gelation. FPI and surimi gels prepared at 25°C for 18min exhibited higher β-sheet contents and more chemical bonds such as hydrophobic interactions and disulfide bonds than those at 5°C for 6min. Results suggested that controlling comminution is important to improve gel qualities in FPI and surimi from tropical fish like tilapia. Moreover, FT-IR and Raman spectroscopies are useful complementary tools for elucidating the change in the structure of protein during comminution and gelation.
authors.affiliation: Oregon State University Seafood Research and Education Center, 2001 Marine Drive #253, Astoria, OR 97103, USA. Electronic address: yuka.kobayashi@oregonstate.edu.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Kobayashi
authors.affiliation: Chemistry Department, University of Portland, 5000 N. Willamette Blvd, Portland, OR 97203, USA. Electronic address: mayer@up.edu.
authors.forename: Steven G
authors.initials: SG
authors.lastname: Mayer
authors.affiliation: Oregon State University Seafood Research and Education Center, 2001 Marine Drive #253, Astoria, OR 97103, USA. Electronic address: jae.park@oregonstate.edu.
authors.forename: Jae W
authors.initials: JW
authors.lastname: Park
mesh_terms: D000818:Animals; D029941:Fish Proteins / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D017210:Tilapia / Q000382:microbiology*
chemical_list: D029941:Fish Proteins
keywords: Chopping conditions; FT-IR spectroscopy; Fish protein isolate; Raman spectroscopy; Surimi