Concentration and stabilization of C20–22 n-3 polyunsaturated fatty acid esters from the oil of Sardinella longiceps

Abstract

Methyl esters of C20–22 n-3 polyunsaturated fatty acids derived from sardine oil triglycerides were concentrated to 86% purity with greater than 30% recovery by argentated chromatography. The synergistic effect of ethyl acetate fractions of seaweeds Kappaphycus alvarezii, Hypnea musciformis and Jania rubens used in 0.1:0.2:0.2 (%, w/w) ratio in arresting oxidative degradation of the n-3 PUFA methyl ester concentrate was demonstrated during accelerated storage. The induction time (6.8 h) and antioxidant activity indices (>24) were greater for n-3 PUFA concentrates supplemented with seaweed extracts than antioxidants BHT and a-tocopherol (<5 h and <17, respectively). Nuclear Magnetic Resonance spectroscopy was employed to study the oxidative changes of fatty acid signals of PUFA concentrate during accelerated storage. Potential of seaweeds to improve the storage stability of C20–22 n-3 fatty acid methyl esters was studied. This study has applications in development of food and pharmaceutical products