title: Effect of electron beam on chemical changes of nutrients in infant formula.
abstract: Infant milk formula has recently been implicated as a transmission vehicle for an emerging foodborne pathogen, Enterobacter sakazakii, resulting in high mortality rates. Electron beam (e-beam) efficiently and non-thermally inactivates foodborne pathogens, including E. sakazakii, in infant milk formula. However, the effects of e-beam on chemical changes of nutrients in infant formula have not been determined. Therefore, the objective of this study was to fulfill this gap. Dehydrated infant milk formula was processed with e-beam at 0 (control) to 25 kGy. Amino acid, fatty acid, and mineral profiles (AAP, FAP, and MP, respectively), as well as protein degradation and lipid oxidation, were determined. There were no differences (P>0.05) in FAP, AAP, and MP. SDS-PAGE electrophoresis qualitatively detected three major protein bands in all samples up to 25 kGy. Densitometry analysis of SDS-PAGE gels confirmed no size degradation (P>0.05) as a function of increased e-beam dose. Totol-volatile-basic-nitrogen (TVBN) excluded (P>0.05) protein degradation due to microbial activity. There was no increase (P>0.05) in lipid oxidation, as assessed with thiobarbituric-reactive-substances (TBARS), except in samples processed at 25 kGy. Dehydrated formula has low water activity, which likely protected nutrients from e-beam-induced chemical changes. This study demonstrates that proteins, lipids, and minerals in infant milk formula are stable when processed with e-beam up to 25 kGy at low temperature and under anaerobic conditions.
authors.affiliation: West Virginia University, Division of Animal and Nutritional Sciences, P.O. Box 6108, Morgantown, WV 26506, USA.
authors.forename: Adiam
authors.initials: A
authors.lastname: Tesfai
authors.forename: Sarah K
authors.initials: SK
authors.lastname: Beamer
authors.forename: Kristen E
authors.initials: KE
authors.lastname: Matak
authors.forename: Jacek
authors.initials: J
authors.lastname: Jaczynski
mesh_terms: D000596:Amino Acids / Q000032:analysis; D005227:Fatty Acids / Q000032:analysis; D005514:Food Irradiation / Q000295:instrumentation / Q000379:methods*; D005720:Gamma Rays; D007225:Infant Food / Q000032:analysis / Q000528:radiation effects*; D041943:Infant Formula / Q000737:chemistry*; D008903:Minerals / Q000032:analysis; D009753:Nutritive Value / Q000528:radiation effects; D011506:Proteins / Q000032:analysis
chemical_list: D000596:Amino Acids; D005227:Fatty Acids; D008903:Minerals; D011506:Proteins
keywords: Amino acid profile; Electron beam; Fatty acid profile; Food irradiation; Infant milk formula; Ionising radiation; Lipid oxidation; Nutritional composition; Nutritional quality