Structured lipids of swine lard and oils from byproducts of skipjack tuna and of common carp

Abstract

The aim was to obtain structured lipids by chemical interesterification of saturated fat (lard) with bleached oils from fish heads (carp and tuna). All materials were characterized by physicochemical analyses, gas chromatography for fatty acid profiles, nuclear magnetic resonance for unsaturated fatty acids esterified in sn-1,3 and sn-2 positions of the triacylglycerols, and differential scanning calorimetry for solid fat content (SFC). The amounts of eicosapentaenoic acid and docosahexaenoic acid were much higher for tuna oil (32%), showing the presence of docosahexaenoic acid in the structured lipids. The higher modifications of lard were with 1% of catalyst and 70:30 ratio of lard : fish oil. Through the SFC analysis, information about the structured lipids’ characteristics were obtained, making it possible to define the most suitable technological applications. After the reaction, SFC reduced from 2% to 30% when compared to the swine lard, and the highest changes had occurred when tuna oil was used. Practical applications In recent years, the growing demand for foods with nutritional properties has aroused the interest about the development of a new generation of lipids, the so-called healthy lipids. This work presents as a differential, the effect evaluation of the fish oils from different cultures (pisciculture and mariculture) in the characteristics of structured lipids, which are obtained by chemical interesterification reaction of these oils with swine lard. The presence of different types of fatty acids in the same triacylglycerol molecule can produce a compound with unique nutritional and metabolic properties. Thus, the use of fish oils with different fatty acid profiles can have a direct effect on the technological applications of the structured lipids. In addition, the incorporation of fatty acids as EPA and DHA, which are not naturally found in fats, besides conferring interesting technological characteristics, increases the nutritional value of the fat.