Extraction of ochratoxin A in bread samples by the QuEChERS methodology

Area of Science:

• Food Chemistry
• Analytical Chemistry
• Mycotoxicology

Background:

• Ochratoxin A (OTA) is a significant mycotoxin found in various food products, including bread.
• Contamination of bread with OTA poses a risk to public health.
• Accurate and efficient methods for OTA detection in food matrices are crucial for regulatory compliance.

Purpose of the Study:

• To optimize and validate a QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method for ochratoxin A extraction from bread samples.
• To determine the optimal parameters for the QuEChERS extraction process.
• To assess the presence of OTA in commonly consumed bread types in Portugal.

Main Methods:

• A 2(3) factorial design was employed to optimize QuEChERS parameters: extraction time, solvent volume, and sample mass.
• Acetonitrile was used as the extraction solvent.
• Liquid chromatography with fluorescence detection (LC-FLD) was utilized for ochratoxin A analysis.

Main Results:

• Optimal extraction conditions were identified as 5 g of sample, 15 mL of acetonitrile, and 3 minutes of agitation.
• Method validation demonstrated high recoveries, ranging from 94.8% to 96.6%.
• The limit of quantification (LOQ) for ochratoxin A was determined to be 0.05 μg kg(-1).

Conclusions:

• The optimized QuEChERS method provides an efficient and reliable approach for ochratoxin A determination in bread.
• Analysis of 20 bread samples from Portugal revealed no exceedance of the European legal limit for OTA (3 μg kg(-1)).
• The developed method is suitable for routine monitoring of ochratoxin A in bread products.