The effect of dietary supplementation of soybean oils on the color and fatty acid profile of Nubian goat meat.

Abstract

Of 15 castrated male Nubian goats (about 40 kg and 10 months of age), five were assigned to one of three dietary treatments: 1) 30% Bermuda grass plus 55.7% com and 13.1% soybean meal (control); 2) 30% Bermuda grass plus 52.8% corn, 13.5% soybean meal, and 2.5% soybean oil; and 3) 30% Bermuda grass plus 49.8% corn, 14.0% soybean meal, and 5.0% soybean oil. Soybean oil was sprayed on Bermuda grass and mixed well. All diets were isonitrogenous. Goats were slaughtered at an average live weight of 60 kg. Our objective was to determine whether dietary soybean oil altered the fatty acid composition and the color stability of goat loin chops (longissimus muscle) after being stored at 2℃ for 9 days. Adding soybean oil (2.5 and 5.0%) to goat diets decreased (p＜0.05) the percentage of trans-11 C18:1 (p＜0.05), C18:1, C18:3, C20:5 (eicosapentaenoic acid), and C22:0 fatty acids. The percentage of cis-9, trans-11 isomer of CLA (conjugated linoleic acid) increased slight1y as the percentage of supplemental soybean oil increased, but the differences across the treatments were not significant. Treatments with soybean oil increased the levels of MUFA (monounsaturated fatty acids) and PUFA (polyunsaturated fatty acids), but decreased the level of SFA (saturated fatty acids). The Hunter L(superscript *) of the loin chops increased, but the pH value decreased with increased soybean oil supplementation. Loin chops from goats fed 5.0% supplemental soybean oil had a consistently higher Hunter L(superscript *) value at all days of storage