Structural Changes Imposed on Whey Proteins by UV Irradiation in a Continuous UV Light Reactor

被引:95
作者
Kristo, Eleana [1 ]
Hazizaj, Artan [1 ]
Corredig, Milena [1 ]
机构
[1] Univ Guelph, Dept Food Sci, Guelph, ON N1G 2W1, Canada
关键词
UV irradiation; UV reactor; whey proteins; denaturation; BETA-LACTOGLOBULIN-A; ALPHA-LACTALBUMIN; FLUORESCENCE; DENATURATION; REDUCTION; MILK;
D O I
10.1021/jf300278k
中图分类号
S [农业科学];
学科分类号
09 ;
摘要
The objective of this study was to investigate the structural changes of whey proteins during exposure in a continuous-flow UV reactor. Varying UV irradiation dosages were obtained by controlling the flow rate and the mixing speed. Whey protein isolate (WPI) solutions at concentrations of 1% and 5% (w/v) were circulated at flow rates ranging from 30 to 800 mL.min(-1), and changes in physicochemical properties of the proteins were investigated. Intrinsic fluorescence spectra and surface hydrophobicity measurements suggested changes in the tertiary structure of the proteins with UV exposure. The UV treatment also increased the concentration of total and accessible thiol groups in 1% WPI solutions, while no change was measured in 5% WPI solutions. Size-exclusion chromatography demonstrated the formation of UV-induced aggregates and oxidation products (N-formylkynurenine and dityrosine) of aromatic amino acids. Furthermore, the UV-induced changes in protein conformation increased the susceptibility of whey proteins to pepsin hydrolysis.
引用
收藏
页码:6204 / 6209
页数:6
相关论文
共 26 条
[1]   Influence of apple cultivars on inactivation of different strains of a Escherichia coli O157:H7 in apple cider by UV irradiation [J].
Basaran, N ;
Quintero-Ramos, A ;
Moake, MM ;
Churey, JJ ;
Worobo, RW .
APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 2004, 70 (10) :6061-6065
[2]  
Bintsis T, 2000, J SCI FOOD AGR, V80, P637, DOI 10.1002/(SICI)1097-0010(20000501)80:6<637::AID-JSFA603>3.0.CO
[3]  
2-1
[4]   Probing structural features of water-insoluble proteins by front-face fluorescence [J].
Bonomi, F ;
Mora, G ;
Pagani, MA ;
Iametti, S .
ANALYTICAL BIOCHEMISTRY, 2004, 329 (01) :104-111
[5]  
Burton H., 1951, Dairy Science Abstracts, V13, P229
[6]   STUDIES ON RIPENING OF GRANA PADANO CHEESE MANUFACTURED FROM MILK IRRADIATED WITH UV LIGHT [J].
CASERIO, G ;
BIANCHI, MA ;
BERETTA, G ;
DRAGONI, I .
EUROPEAN JOURNAL OF APPLIED MICROBIOLOGY, 1975, 1 (03) :247-257
[7]   Toward understanding tryptophan fluorescence in proteins [J].
Chen, Y ;
Barkley, MD .
BIOCHEMISTRY, 1998, 37 (28) :9976-9982
[8]   The peptide bond quenches indole fluorescence [J].
Chen, Y ;
Liu, B ;
Yu, HT ;
Barkley, MD .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1996, 118 (39) :9271-9278
[9]   Heat-induced denaturation/aggregation of β-lactoglobulin A and B:: kinetics of the first intermediates formed [J].
Croguennec, T ;
O'Kennedy, BT ;
Mehra, R .
INTERNATIONAL DAIRY JOURNAL, 2004, 14 (05) :399-409
[10]   Interactions between alpha-lactalbumin and beta-lactoglobulin in the early stages of heat denaturation [J].
Dalgleish, DG ;
Senaratne, V ;
Francois, S .
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, 1997, 45 (09) :3459-3464