DETERMINATION OF OXIDATION STABILITY OF SOYBEAN OIL WITH THE OXIDATIVE STABILITY INSTRUMENT - OPERATION PARAMETER EFFECTS

Operation parameters of the oil stability index instrument were evaluated to determine their effect on the oxidative stability of commercial soybean oil. A factorial design was developed to evaluate the following three parameters, each at two levels, sample weight (2.5 or 5.0 g), conductivity tube temperature (20 or 30 degrees C), and air flow rate (12 or 20 L/h), for a total of eight observations. Significance testing indicated that sample size and air flow rate affected oil oxidative stability independently (P < 0.001), but not in combination. The conductivity tube temperature did not affect the oxidation stability index.