A Rapid Method for Determining the Oxidative Stability of Oils Suitable for Breeder Size Samples

Area of Science:

• Analytical Chemistry
• Food Science
• Biochemistry

Background:

• Assessing the oxidative stability of breeder's oil is crucial for quality control and shelf-life determination.
• Traditional methods for monitoring oil oxidation can be time-consuming and require larger sample volumes.
• Developing rapid and sensitive methods for antioxidant screening is essential for oilseed research.

Purpose of the Study:

• To develop and validate a thin-layer chromatography with a flame ionization detector (TLC-FID) method for assessing breeder's oil stability.
• To investigate the relationship between polar compound formation and oil oxidation.
• To evaluate the efficacy of tocopherols as antioxidants in breeder's oil under varying conditions.

Main Methods:

• Development of a TLC-FID method for analyzing polar compounds in oxidized oil samples.
• Oxidation of oil samples at different temperatures (45°C and 65°C) to assess stability.
• Quantification of polar material and correlation with peroxide value (PV).
• Evaluation of antioxidant activity of tocopherol isomers, particularly γ-tocopherol.

Main Results:

• A linear relationship was observed between peroxide value (PV) and polar material content in oxidized oil.
• Oil samples oxidized readily on chromarods, even at low temperatures, facilitating rapid antioxidant screening.
• Oil oxidation rate at 45°C was low, but polar material accumulation was linear with reaction time.
• At 65°C, linearity between polar material and reaction time was maintained below 50% polar material.
• γ-tocopherol demonstrated the highest antioxidant potency, influencing oxidative stability significantly at 65°C.
• At 45°C and 55°C, oxidative stability depended on both tocopherol content and polyunsaturated fatty acids.

Conclusions:

• TLC-FID is a suitable and efficient method for monitoring oil oxidation and screening antioxidants in breeder's oil.
• The method offers advantages such as minimal sample requirement (1-2 μL) and simultaneous analysis of multiple samples.
• Understanding the influence of temperature and specific tocopherol isomers on oxidative stability is key for optimizing oil quality.