Comparison of rancimat evaluation modes to assess oxidative stability of fish oils

Abstract

Two Rancimat evaluation modes, the induction period (IP), and the time needed to achieve a selected difference in conductivity (tΔK) were compared for assessing relative stability of anchovy sardine, and hake liver oils. Mean coefficients of variation were 2.5 and 2.4% for IP and tΔK values, respectively, for oils oxidized in the range 55-90°C. Natural logarithms of IP and tΔK values varied linearly with temperature (P< 0.001). A linear relationship (r = 0.999) was established between the IP and tΔK values (P< 0.001). Relative oxidative stability of fish oils was determined with the same degree of confidence by either IP or tΔK values.