Effects of gamma radiation on microbial, physicochemical, and structural properties of whey protein model system.
Gamma radiation has been used in food processing for many years, though it has certain effects on food components. Whey protein solutions (10%/30%, wt/vol) were treated with gamma radiation at various dosages (10-25 kGy) and evaluated for microbial changes in the solutions and physicochemical and structural changes of whey proteins. Whey protein solutions after gamma radiation showed substantially lower populations of all viable microorganisms than those of controls. The 10% whey protein solution treated at radiation of 20 or 25 kGy remained sterile for up to 4 wk at room temperature. Gamma radiation increased viscosity and turbidity and decreased soluble nitrogen of whey protein solutions compared to nonradiated control samples regardless of radiation dosage. Nonreducing sodium dodecyl sulfate-PAGE suggested that whey proteins under gamma radiation treatment formed aggregates with high molecular weights. Reducing sodium dodecyl sulfate-PAGE showed that disulfide bonds played a role in gamma radiation-induced whey protein cross-linking. Scanning and transmission electron microscopy micrographs exhibited large aggregates of whey proteins after gamma radiation treatment. Results suggested that gamma radiation could be applied to whey protein solution for purposes of reducing microbial counts and cross-linking protein molecules.
['Wang|X B|XB|', 'Wang|C N|CN|', 'Zhang|Y C|YC|', 'Liu|T T|TT|', 'Lv|J P|JP|', 'Shen|X|X|', 'Guo|M R|MR|']
D000818:Animals D001419:Bacteria D002417:Cattle D004591:Electrophoresis, Polyacrylamide Gel D005514:Food Irradiation D005720:Gamma Rays D046529:Microscopy, Electron, Transmission D008954:Models, Biological D014783:Viscosity D000067796:Whey D000067816:Whey Proteins
gamma radiation structural property whey protein physicochemical property