Oxidation degree of soybean oil at induction time point under Rancimat test condition: Theoretical derivation and experimental observation
Related Experiment Video
Updated: Jan 26, 2026

Enhanced Oil Recovery using a Combination of Biosurfactants
Published on: June 3, 2022
1International Joint Research Laboratory for Lipid Nutrition and Safety at Jiangnan University, School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, PR China.
Abstract:
Indices including conductivity, short-chain carboxylic acids, total polar material, acid value, peroxide value and fatty acid composition in water or oil were monitored during Rancimat test of soybean oil from 90 °C to 120 °C. Formic, acetic, propionic and butyric acids in water were detected by ion chromatography. The results showed that all indices had two-stage oxidation rates of initiation (ki) and propagation (kp) at each temperature. Induction period (IP) computed from conductivity and other indices were well correlated (R2 = 0.9980-0.9999). According to the Arrhenius model and empirical equation, ki increased exponentially with temperature (T) while IP decreased exponentially with T. Oxidation degree of oil at induction time point IP*ki was found to be independent of heating time and temperature. The transition between two models was theoretically derived and proved by H NMR. Evaluation of IP*ki may provide a new route to correlate Rancimat data with shelf life of edible oil.
Related Concept Videos
One-Degree-of-Freedom System
A one-degree-of-freedom system is defined by an independent variable that determines its state and behavior. One example of a one-degree-of-freedom system is a simple harmonic oscillator, such as a...
Degrees of Freedom
For example, suppose there are three unknown numbers whose mean is 10; although we can freely assign values to the first and second numbers, the value of the last number can not be arbitrarily assigned.
Degrees of Freedom
For example, suppose there are three unknown numbers whose mean is 10; although we can freely assign values to the first and second numbers, the value of the last number can not be arbitrarily...
Degree of Unsaturation
The degree of unsaturation for hydrocarbons is U = (2C + 2 − H) / 2, where C is the number of carbon atoms and H is the number of hydrogen atoms.
Theoretical Approaches to Psychological Disorder
Biological approach
The biological approach posits that internal, organic factors are the primary causes of such disorders. This perspective emphasizes brain structure and function, genetic predispositions, and neurotransmitter imbalances. For example, schizophrenia has been associated with both genetic...
Theoretical Foundations of Nursing Practice
Theories provide a perspective to assess patients' conditions and organize data and methods. They also assist in analyzing and interpreting information. They represent a...

