Characterization of the Stability of Vegetable Oil by Synchronous Fluorescence Spectroscopy and Differential Scanning Calorimetry (DSC)

Abstract

Synchronous fluorescence spectroscopy and differential scanning calorimetry were applied to evaluate the stabilities of the peanut, corn, sunflower, and rapeseed oil. The results showed that when the vegetable oils were severely oxidized, their fluorescence emission intensities became significantly weakened and their fluorescence peaks showed large red shifts, indicating a significant change in the antioxidant concentrations in the oils. When the peanut, corn, sunflower, and rapeseed oil were heated at 190 °C, their relative fluorescence intensities were 0.28, 0.38, 0.35, and 0.28, the red shifts were 15, 8, 15, and 10 nm, and their peroxide values increased to 31.80, 24.43, 22.17, and 37.29 meq/kg, respectively. Thus, the relative fluorescence intensity and the red shift may be used to evaluate the degree of oxidation and stability of the vegetable oils. This method is promising to characterize the stability of vegetable oils.

Keywords:

• Differential scanning calorimetry (DSC)
• synchronous fluorescence
• vegetable oils
• oxidative stability

Disclosure statement

The authors declare that they have no conflicts of interest.

Additional information

Funding

This work was financially supported by Shanghai University of Engineering Science by grant number 0244-A4-0100-20-SDJH0405.