title: Effect of pulsed-light treatment on milk proteins and lipids.
abstract: Pulsed-light treatment offers the food industry a new technology for food preservation. It allows the inactivation of numerous micro-organisms including most infectious foodborne pathogens. In addition to microbial destruction, one can also question whether pulsed-light treatment induced conformational changes in food components. To investigate this question, the influence of pulsed-light treatment on protein components of milk was evaluated by using UV spectroscopy, spectrofluorometry, electrophoresis, and determination of amino acid composition. Pulsed-light treatment resulted in an increase of UV absorbance at 280 nm. The intrinsic tryptophan fluorescence of beta-lactoglobulin (BLG) showed a 7 nm red shift after 10 pulses. SDS-PAGE showed the formation of dimers after treatment of BLG by 5 pulses and more. No significant changes in the amino acid composition of proteins and lipid oxidation were observed after pulsed-light treatment. The obtained results indicated changes in the polarity of the tryptophanyl residue microenvironment of BLG solutions or changes in the tryptophan indole structure and some aggregation of studied proteins. Hence, pulsed-light treatment did not lead to very significant changes in protein components; consequently, it could be applied to process protein foods for their better preservation.
authors.affiliation: UMR-INRA 1014 SECALIM ENVN/ENITIAA, Nantes, France.
authors.forename: Noura
authors.initials: N
authors.lastname: Elmnasser
authors.forename: Michèle
authors.initials: M
authors.lastname: Dalgalarrondo
authors.forename: Nicole
authors.initials: N
authors.lastname: Orange
authors.forename: Amina
authors.initials: A
authors.lastname: Bakhrouf
authors.forename: Thomas
authors.initials: T
authors.lastname: Haertlé
authors.forename: Michel
authors.initials: M
authors.lastname: Federighi
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Chobert
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D005223:Fats / Q000032:analysis*; D005519:Food Preservation / Q000379:methods*; D007782:Lactoglobulins / Q000032:analysis; D008027:Light / Q000009:adverse effects; D008892:Milk / Q000737:chemistry* / Q000528:radiation effects; D008894:Milk Proteins / Q000032:analysis*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000596:Amino Acids; D005223:Fats; D007782:Lactoglobulins; D008894:Milk Proteins