Development of an HPLC-PDA-based analytical method for quantifying thiodipropionic acid in vegetable oil

Area of Science:

• Food Chemistry
• Analytical Chemistry
• Food Science

Background:

• Lipid oxidation in edible oils leads to quality degradation.
• Effective antioxidants are crucial for preserving oil quality.
• Thiodipropionic acid (TDPA) is a thermally stable compound of interest as a potential food additive.

Purpose of the Study:

• To develop and validate an HPLC-PDA method for quantifying TDPA in vegetable oils.
• To assess the antioxidant efficacy of TDPA under accelerated oxidation conditions.
• To evaluate TDPA's suitability for regulatory monitoring and food safety.

Main Methods:

• High-Performance Liquid Chromatography with Photodiode Array detection (HPLC-PDA) was developed and validated.
• Method validation included specificity, linearity, sensitivity, accuracy, and precision assessments.
• Accelerated oxidation tests were conducted at 60 °C for 12 days, comparing TDPA with BHA and BHT.

Main Results:

• The HPLC-PDA method showed excellent performance (R² > 0.999) with low detection (0.44 μg/mL) and quantification limits (1.33 μg/mL).
• TDPA was not detected in 50 commercial vegetable oil samples.
• TDPA demonstrated sustained lipid oxidation suppression, retaining over 70% of its concentration and outperforming BHA and BHT in long-term efficacy.

Conclusions:

• TDPA exhibits potential as a long-acting antioxidant in edible oils.
• The validated HPLC-PDA method is reliable for TDPA quantification in vegetable oils.
• TDPA warrants further consideration for food additive designation and safety assessment.