J. Anim Sci., doi: 10.2527/jas.2007-0038
©Copyright, 2007, The American Society of Animal Science
Unsaturated fatty acids and sodium affect the liver-like off flavor in cooked beef
B. E. Jenschke 1,
J. M. Hodgen 1,
J. L. Meisinger 1,
A. E. Hamling 1,
D. A. Moss 1,
M. Lundesjö Ahnström 2,
K. M. Eskridge 3,
C. R. Calkins 1*
1 University of Nebraska, Department of Animal Science, Lincoln, NE, 68583
2 Swedish University of Agricultural Sciences, Department of Food Science, P.O. Box 7051, SE-75007, Uppsala, Sweden
3 University of Nebraska, Department of Statistics, Lincoln, NE, 68583
* To whom correspondence should be addressed. E-mail: ccalkins1{at}unl.edu.
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Abstract |
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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, two 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 five different feedlots, but only identified 29 as having an off-flavor. A kappa statistic was generated to assess the level of agreement of the two panelists which indicated the panelists moderately and substantially agreed when judgments were based on smell exclusively or smelling and tasting, respectively. Although the agreement was acceptable (
= 0.57 and 0.76), there was not enough variation in the liver-like off flavor and off-flavor intensity for the two panelists to detect differences when compared with an independent sensory panel. Phase II identified factors that lead 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, sodium, 16:1, cis 18:1(n-7), 20:2(n-6) and 20:3(n-6) significantly (P = 0.021) explained 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.
Key Words:
Beef, Fatty acids, Flavor, Liver-like, Knuckles
