title: Unsaturated fatty acids and sodium affect the liver-like off-flavor in cooked beef.
abstract: Beef knuckles (n = 60) were chosen from a population of 328 knuckles to test a selection procedure and determine the potential causes of liver-like off-flavor. In phase I, 2 independent panelists were allowed to smell the aromas or smell and taste samples of cooked beef to determine the presence or absence of the liver-like off-flavor and off-flavor intensity. The panelists tested knuckles from 5 feedlots, but only identified 29 as having an off-flavor. A kappa statistic was generated to assess the level of agreement of the 2 panelists that indicated the panelists moderately or substantially agreed when judgments were based on smell exclusively or smelling and tasting, respectively. Although the agreement was acceptable (kappa = 0.57 and 0.76), there was not enough variation in the liver-like off-flavor and off-flavor intensity for the 2 panelists to detect differences compared with an independent sensory panel. Phase II identified factors that led to the development of the liver-like off-flavor in beef. The M. rectus femoris from knuckles identified from phase I were used. Sensory analysis, proximate composition, heme iron, mineral content, and fatty acid analyses were conducted. Stepwise regression was used to identify factors contributing to the liver-like off-flavor. Specifically, Na, 16:1, cis 18:1(n-7), 20:2(n-6), and 20:3(n-6) fatty acids explained (P = 0.021) 46% of the variation of the liver-like off-flavor. Although previously reported as playing a role in the development of the liver-like off-flavor, iron, heme iron, and pH had no effect in this study.
authors.affiliation: Department of Animal Science, University of Nebraska, Lincoln 68583, USA.
authors.forename: B E
authors.initials: BE
authors.lastname: Jenschke
authors.forename: J M
authors.initials: JM
authors.lastname: Hodgen
authors.forename: J L
authors.initials: JL
authors.lastname: Meisinger
authors.forename: A E
authors.initials: AE
authors.lastname: Hamling
authors.forename: D A
authors.initials: DA
authors.lastname: Moss
authors.forename: M
authors.initials: M
authors.lastname: Lundesjö Ahnström
authors.forename: K M
authors.initials: KM
authors.lastname: Eskridge
authors.forename: C R
authors.initials: CR
authors.lastname: Calkins
mesh_terms: D000818:Animals; D002417:Cattle; D003258:Consumer Behavior; D005231:Fatty Acids, Unsaturated / Q000009:adverse effects* / Q000494:pharmacology; D005504:Food Analysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000032:analysis; D008460:Meat / Q000032:analysis / Q000592:standards*; D009812:Odorants / Q000032:analysis*; D012964:Sodium / Q000009:adverse effects* / Q000494:pharmacology; D013649:Taste / Q000187:drug effects / Q000502:physiology
chemical_list: D005231:Fatty Acids, Unsaturated; D012964:Sodium; D007501:Iron