FREE FATTY-ACID COMPOSITION OF THE ADIPOSE-TISSUE OF INTACT AND CASTRATED LAMBS SLAUGHTERED AT 12 AND 30 WEEKS OF AGE

Free fatty acids from adipose tissue of rams and wethers slaughtered a t 12 and 30 weeks of age were isolated by a modified Bligh and Dyer me thod and analyzed by gas chromatography-mass spectrometry. A total of 15 free fatty acids were positively identified. At 12 weeks of age, ra ms had nonsignificantly higher levels of the flavor-significant compou nds, 4-methyloctanoic and 4-methylnonanoic acids, than wethers. At 30 weeks of age, differences in the levels of these acids in rams and wet hers became significant and 4-methyloctanoic and 4-methylnonanoic acid s increased by 13- and 4-fold, respectively, in the noncastrated anima ls. Log odor unit values indicated that 4-methyloctanoic acid was pres ent at or above its odor threshold value in rams and wethers of both s laughter ages, but that the value was much higher for 30-week-old rams . 4-Methylnonanoic acid was present below its odor threshold value in all samples.