|Taylor, Joshua - Bret|
Submitted to: International Congress of Meat Science and Technology Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 7/1/2004
Publication Date: 11/1/2004
Citation: Lawler, T.L., Marchello, M.J., Taylor, J.B., Caton, J.S. 2004. Effect of supranutritional and organically-bound dietary selenium on the nutritive value and case longevity of beef. Proceedings of the 50th International Congress of Meat Science and Technology. Helsinki, Finland. p. 135-139. Interpretive Summary: Supranutritional dietary selenium, from high selenium wheat, enhanced selenium concentration and glutathionine peroxidase activty of the m. gastrochemius, and decreased drip loss from the m. longissimus. Caution should be used when assuming that enhanced Se concentration of a meat product will result in greater product stability during case display. This study clearly demonstrates the nutriative value of beef muscle products can be enhanced using feeds naturally high in selenium without negatively affecting the quality or case longevity of beef muscle.
Technical Abstract: Twenty crossbred beef steers (351 ± 24 kg initial body weight [BW]), individually fed (120 days) either 0.35 (n = 11; adequate) or 2.70 (n = 9; supranutritional) mg selenium/kg BW/day, were utilized to assess the affects of supranutritional organically-bound selenium (Se) on the nutritive value and case life characteristics of the m. gastrochemius and m. longissimus, respectively. High Se wheat (10.3 mg/kg) directly replaced adequate Se wheat (0.40 mg/kg) to deliver the Se treatment. Immediately following slaughter, carcasses were placed in a cooler (4 C), and m. gastrochemius samples were collected every 12 hours during a 48 hour chilling period. The repeated samples were analyzed for glutathione peroxidase activity, and the hour 0 sample was additionally analyzed for expressible moisture, dry matter, ash, nitrogen, pH and lipids. At 48 hour post slaughter, two steaks (2.5 cm) were cut from the m. longissimus lumborum, weighed, placed on a styrofoam tray, wrapped with a clear oxygen-permeable film, and displayed in a retail case (2.78ºC; fluorescent lighting) for 12 days, and repeated measures of Hunter L, a and b values, subjective color scores, drip loss weights were collected. On day 12, cooking loss was measured. M. gastrochemius from steers fed high Se wheat diets had greater Se concentration and GSH-Px activity than samples from steers fed adequate Se (p < 0.05). Although supranutritional Se had no influence on color change (p > 0.16), m. longissimus from steers fed the high Se wheat diets lost less moisture (drip loss; p < 0.01). This indicates that a supranutritional Se diet results in the mitigation of protein breakdown and subsequent release of water. Based on these results, caution should be used when assuming that enhanced Se concentration of a meat product will result in greater product stability during case display. However, the nutritive value of beef muscle products can be enhanced using feeds naturally high Se without negatively affecting the case longevity of beef muscle.