Intramuscular fat and fatty acid composition of longissimus muscle from divergent pure breeds of cattle

Abstract

The objective of this study was to compare the fatty acid (FA) composition of intramuscular fat from the LM of 3 divergent breeds of cattle: Angus (AN, n = 9), Brahman (BR, n = 7), and Romosinuano (RM, n = 11). Cattle were blocked by breed and finished 129 d before slaughter in one year and 157 d in the next year. Longissimus muscle samples were collected from each carcass between the 10th and 13th ribs, trimmed of external fat, frozen in liquid nitrogen, homogenized, and used for fat extraction, using a modified Folch procedure. Extracted fat was analyzed for FA by using a GLC system with an HP-88 capillary column. Fatty acid composition was expressed using both a normalized percentage (%) and gravimetric calculation (mg/g of fresh muscle tissue) in relation to degree of saturation, which was determined using a saturation index (ratio of total SFA to total unsaturated FA). Crude fat determination revealed that LM from AN purebred cattle had the greatest amount of intramuscular fat (7.08%; P = 0.001). Although intramuscular fat of LM from RM contained a reduced percentage of total SFA (P = 0.002) compared with AN, it had the greatest percentage of total PUFA (P < 0.001 and P = 0.020). The percentages of total MUFA were similar among the 3 breeds (P = 0.675). The gravimetric calculation, a measure of actual FA concentration, showed significantly greater concentrations of SFA (26.67 mg/g), MUFA (26.50 mg/g), and PUFA (2.37 mg/g) in LM from AN cattle, as compared with LM from BR and RM cattle (P < 0.001). Interestingly, BR purebreds had the least PUFA concentration (1.49 mg/g; P <or= 0.001) in the LM, although their intramuscular fat content was similar to that of RM (P = 0.924). Regardless of breed, the MUFA proportion was always the greatest (47.58%; P <or= 0.005), whereas PUFA was the least contributor to FA composition (1.49 to 2.37 mg/g and 4.36 to 8.78%; P < 0.001). Beef LM fatty acid composition was characterized by palmitic and oleic acids being the most abundant FA (P < 0.001). These results suggested a genetic variation in FA synthesis and deposition among breeds that influenced both marbling and its composition.

Genome wide association study of cholesterol and poly- and monounsaturated fatty acids, protein, and mineral content of beef from crossbred cattle

“…Breed differences between Angus, Brahman, and Romosinuano for PUFA percentage but not MUFA percentage were reported by Dinh et al (2010). When breed comparison was made on a concentration (mg/g) basis, Dinh et al (2010) reported that significant differences still existed for PUFA and Angus cattle were significantly greater for MUFA concentration than the other two breeds.…”

“…When breed comparison was made on a concentration (mg/g) basis, Dinh et al (2010) reported that significant differences still existed for PUFA and Angus cattle were significantly greater for MUFA concentration than the other two breeds. A rank change between the breeds existed depending on the units of measurement (mg/g or percentage) for PUFA.…”

Intramuscular fat and fatty acid profile of muscle of lambs finished in irrigated pasture

“…This may be the result of lower biohydrogenation of oleic acid in the rumen or increased enzyme stearoyl-CoA desaturase (SCD) activity in muscle tissue of animals of this breed. However, no study has suggested breed-related differences in biohydrogenation in the rumen (Dinh et al 2010). Bauman et al (1999) and Dinh et al (2010) suggested that the increase in MUFA concentration, especially regarding the increased concentration of oleic acid, might be an indicator of desaturase activity.…”

“…However, no study has suggested breed-related differences in biohydrogenation in the rumen (Dinh et al 2010). Bauman et al (1999) and Dinh et al (2010) suggested that the increase in MUFA concentration, especially regarding the increased concentration of oleic acid, might be an indicator of desaturase activity. Although SO lambs have presented the highest average for the concentration of MUFA, they did not differ from the other genetics groups.…”

“…In tissues, the concentration of oleic acid is dependent upon the activity of D 9 desaturase (Smith et al 2006) that is the major lipogenic enzyme that catalyses the conversion of palmitic (C16:0) to palmitoleic (C16:1) and estearic (C18:0) to oleic (C18:1). Dinh et al (2010) explain that the significant presence of oleic acid is explained by D 9 desaturase, which may convert as much as 10% of estearic to oleic acid in the enterocyte (Byers & Schelling 1993). Oleic acid is considered hypolipidaemic, as it reduces cholesterol and triglycerides in plasma (EFSA 2010;Dı´az et al 2011).…”