X. Fernandez et al., EFFECT OF MUSCLE-TYPE AND FOOD-DEPRIVATION FOR 24 HOURS ON THE COMPOSITION OF THE LIPID FRACTION IN MUSCLES OF LARGE WHITE-PIGS, Meat science, 41(3), 1995, pp. 335-343
The present study was designed to examine the lipid composition of a p
redominantly glycolytic (M. longissimus lumborum, LL) and a predominan
tly oxidative (M. semispinalis capitis, SC) muscle sampled at slaughte
r from Large White pigs fed or deprived of food for 24 h. The intramus
cular lipid content was almost four-fold higher in the red SC than in
the white LL. When expressed on a muscle tissue basis, the results ind
icated that the LL had significantly lower amount of tri-, di- and mon
oglycerides, free fatty acids, cholesterol and phospholipids than the
SC. In both muscles, phosphatidylcholine represented the major constit
uent of the phospholipid fraction. The difference in phospholipid cont
ent between the LL and the SC was significant only for cardiolipin, ph
osphatidylethanolamine and phosphatidylinositol. When expressed on tot
al lipid basis, the results showed that the SC contained significantly
lower amount of phospholipids and higher amount of triglycerides than
the LL, thus suggesting that the influence of muscle type on the cont
ent of intramuscular lipid was primarily due to a difference in the am
ount of triglycerides. Food deprivation for 24 h resulted in a signifi
cantly higher content of free fatty acids, as expressed on a muscle ti
ssue basis, in both muscles. Relative to total lipid, food deprivation
resulted in increased levels of free fatty acids and monoglycerides o
nly in the LL. These results suggest that food deprivation for 24 h in
duced lipolysis in muscle, as evidenced by a modification in the relat
ive composition of the neutral lipid fraction, but that this effect wa
s muscle-dependent.