OXIDATIVE STABILITY AND CHARACTERIZATION OF ANTIOXIDANTS IN CHIA SEED OILS

IXTAINA, VANESA YANET; SPOTORNO, VIVIANA; MATEO, CARMEN; NOLASCO, SUSANA; TOMÁS, MABEL

Québec City, Canadá

Congreso; 98 th AOCS Annual Meeting & Expo; 2007

The American Oil Chemists' Society

Chia seeds (25-39% oil) have the highest proportion of omega-3-linolenic acid (65-70%) of any known natural source. Vegetable oils are protected by natural, endogenous antioxidants. However, if its contain high concentrations of polyunsaturated fatty acids (PUFA�s), oils are very susceptible to lipid oxidation.The aim of this study was to determine the oxidative stability and natural antioxidants present in chia seed oils.Chia seeds from Guatemala and Argentina were used to obtain the oils by solvent extraction (hexane, 80�C, 8h). Fatty acid compositions were determined by GC and oxidative stability evaluated by Rancimat (98�C,air flow 20Lh-1). Phenolic antioxidants and tocopherols were determined (HPLC-UV- fluorescence). The results indicate that fatty acid composition has an important role on oxidation stability of oils. Chia seed crude oils - high degree of PUFA�s 85%- exhibited induction periods of 2h 25 min for both locations. Argentina chia seed oil presented more total phenolic antioxidant content than Guatemala. Major poliphenolic antioxidants were myricetin and chlorogenic acid while kaempferol and quercetin were recorded only for Guatemala oil. Gamma and delta tocopherol were founded (Guatemala 426.4 �g/g, Argentina 295.3 �g/g). Differences in antioxidant composition could be attributed to different environmental conditions presented in each countries.