The effect of temperature on stability of squeezed soybean oil

Abstract

The effect of temperature (T) on stability of squeezed soybean oil (SSO) were studied by four characterization parameters (CPs, conductivity, peroxide value, isovolumetric combustion heat and acid value)similarities and differences of CPs characterization results were further compared.Under the fixed conditions of relative humidity was 40%, partial pressure of oxygen was 21 kPa, illumination was 800 lx and initial headspace rate was 50%, regulated and controled T to 30 ℃, 40 ℃, 50 ℃, 60 ℃ and 70 ℃ respectively,SSO test samples were oxidized continuously in airtight container for a long time, four CPs at different oxidation time (t) were multiple measured in the same time, curve of CP～t was plotted, kinetic equation was regressed, rate constant (k) and apparent activation energy were calculated, the prediction model of metamorphic time was established and coincidence rate was verified.The results show that CP changed significantly with the increase of T and the extension of t, the oxidative rancidity of SSO has characteristic of simple series reaction,the prediction model of metamorphic time has a good coincidence, CP was different, and there was a big difference in k.The stability of squeezed soybean oil of SSO should be described by multiple CPs.

Keywords

• temperature
• squeezed soybean oil
• stability
• characterization parameters