title: Protein oxidation during frozen storage and subsequent processing of different beef muscles.
abstract: This study examined the relationship between protein and lipid oxidation and the impairment of the water holding capacity (WHC), redness and instrumental hardness occurring during 20 weeks of frozen storage (-18 °C) and subsequent processing (cooking, chilled storage) of psoas major, quadriceps femoris and longissimus dorsi beef patties. Patties were analyzed at sampling times upon thawing (weeks 0, 4, 8, 12 and 20) for lipid (TBARS, hexanal) and protein oxidation products (α-aminoadipic and γ-glutamic semialdehydes, α-aminoadipic acid, Schiff bases). A significant impact of frozen storage on protein oxidation was found, which occurred concomitantly with a loss of WHC, redness and significant changes in the hardness of cooked patties. Heme-iron, endogenous antioxidant enzymes and to a lower extent, fatty acid composition, played a role in the oxidative stability of patties. Plausible mechanisms by which particular protein oxidation changes may lead to loss of WHC and impaired quality traits were discussed.
authors.affiliation: Food Technology, Department of Animal Production and Food Science, University of Extremadura, 10003 Cáceres, Spain.
authors.forename: Mariana
authors.initials: M
authors.lastname: Utrera
authors.forename: Vita
authors.initials: V
authors.lastname: Parra
authors.forename: Mario
authors.initials: M
authors.lastname: Estévez
mesh_terms: D015074:2-Aminoadipic Acid / Q000032:analysis; D000818:Animals; D002417:Cattle; D055598:Chemical Phenomena; D002851:Chromatography, High Pressure Liquid; D003116:Color; D003296:Cooking; D005227:Fatty Acids / Q000032:analysis; D063427:Food Quality; D061353:Food Storage / Q000379:methods*; D005615:Freezing; D008401:Gas Chromatography-Mass Spectrometry; D005971:Glutamates / Q000032:analysis; D050356:Lipid Metabolism / Q000502:physiology; D008460:Meat / Q000032:analysis*; D009124:Muscle Proteins / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000737:chemistry*; D010084:Oxidation-Reduction; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis
chemical_list: D005227:Fatty Acids; D005971:Glutamates; D009124:Muscle Proteins; D017392:Thiobarbituric Acid Reactive Substances; D015074:2-Aminoadipic Acid; C021199:glutamic acid gamma-semialdehyde
keywords: Antioxidant enzymes; Beef; Carbonylation; Freezing; Heme-iron; Muscles