title: FTIR analysis of protein secondary structure in cheddar cheese during ripening.
abstract: Proteolysis is one of the most important biochemical reactions during cheese ripening. Studies on the secondary structure of proteins during ripening would be helpful for characterizing protein changes for assessing cheese quality. Fourier transform infrared spectroscopy (FTIR), with self-deconvolution, second derivative analysis and band curve-fitting, was used to characterize the secondary structure of proteins in Cheddar cheese during ripening. The spectra of the amide I region showed great similarity, while the relative contents of the secondary structures underwent a series of changes. As ripening progressed, the alpha-helix content decreased and the beta-sheet content increased. This structural shift was attributed to the strengthening of hydrogen bonds that resulted from hydrolysis of caseins. In summary, FTIR could provide the basis for rapid characterization of cheese that is undergoing ripening.
authors.affiliation: College of Food Science & Nutritional Engineering, China Agricultural University, Key Laboratory of Functional Dairy, Ministry of Education, Beijing 100083, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Ai-ping
authors.initials: AP
authors.lastname: Liu
authors.forename: Fa-zheng
authors.initials: FZ
authors.lastname: Ren
authors.forename: Xiao-ying
authors.initials: XY
authors.lastname: Zhang
authors.forename: Clark
authors.initials: C
authors.lastname: Stephanie
authors.forename: Lu-da
authors.initials: LD
authors.lastname: Zhang
authors.forename: Hui-yuan
authors.initials: HY
authors.lastname: Guo
mesh_terms: D002364:Caseins / Q000737:chemistry; D002611:Cheese / Q000032:analysis*; D006868:Hydrolysis; D008894:Milk Proteins / Q000737:chemistry; D017433:Protein Structure, Secondary; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D002364:Caseins; D008894:Milk Proteins