Physico-chemical composition, fractionated glycerides and fatty acid profile of chicken skin fat

Skin is one of the several co-products of chicken meat industries, considered as waste, being rarely utilized or underutilized. Brazil is the world leader in chicken exports (3.6 million tons) and the third largest producer with 10.9 million tons, from which 440 000 ton/year are residues. This work aimes at characterizing chicken skin fat (CSF), comparing it with soybean oil, a well-known and abundant compound, evaluating the physico-chemical composition, fractionated glycerides and fatty acid profile, searching for CSF use in interesterification reactions. For that, determination of peroxide and p-anisidine values, as well as thiobarbituric acid, iodine, saponification, acidity, unsaponified matter and refraction indexes were accomplished, besides the glycerides fractionation, followed by FAME derivatization and identification by GC. The nutritional quality indexes were calculated from the lipid profile. CSF showed satisfactory quality due to low acidity (0.65 g oleic acid/100 g), peroxide (2.14 meq/kg), p-anisidine (0.70 absorbance units/g) values, besides presenting high proportion of MUFA (40%). However, due to CSF low hypocholesterolemic/hypercholesterolemic value (HH = 2.72), it may be difficult to use it for nutritional purposes the way it is found, once it tends to increase cholesterol. CSF it is a promising residue for different purposes including interesterification reactions and biodiesel production.