Evaluation of conjugated linoleic acid and other health-related lipid components in raw, boiled and smoked beef

Abstract

Conjugated octadecadienoic (C₁₈:2) Linoleic Acid (CLA) if not destroyed by heat during  processing can be beneficial to health. About 100g of Longissimus dorsi Beef Muscle (LDBM) each was trimmed of external fat and connective tissues and used for this study. Samples were spiced, group into 3 of N=10 samples per group and treated as raw (control), boiled and smoked to internal temperature of 76.1^oC. Samples did not show significant difference (p > 0.05) in the amount of CLA content which had values of 0.60% and 0.40% for boiled and smoked samples respectively. However, these values were different from the raw sample with a value of 2.39 ± 0.01. Boiled samples preserved the total beneficial lipids of CLA, PUFA, MUFA and omega 3 and 6 fatty acids more than smoked samples. The major fatty acids found in the muscle analyzed are palmitic (C₁₆:0), stearic (C₁₈:0) and octadecenoic (C₁₈:1). Omega 3 fatty acids are 1.05%, 1.16% and 1.30 % for boiled, smoked and raw samples respectively and 4.21%, 6.39% and 12. 87% for omega-6 fatty acids in the same order. Ratios of ? -3/? -6 are 0.25, 0.18 and 0.10 for boiled, smoked and raw samples respectively. By preserving the beneficial CLA, the Nigerian traditional high temperature moist-cooking method should not pose any risk in processing beef. Our internal cooking temperature of 76.1^oC for the boiled and smoked beef conforms to USDA cooking temperature for a 'well done' beef.

Key words: Conjugated Linoleic Acid (CLA), Longissimus dorsi muscle, Boiled & Smoked Beef, Omega 3, 6 Fatty Acids.