Physicochemical Characterization of the Pristine E171 Food Additive by Standardized and Validated Methods

Area of Science:

• Food Science
• Materials Science
• Nanotechnology

Background:

• Titanium dioxide (E171) is an authorized food colorant in the EU.
• Concerns exist regarding E171's potential to alter the intestinal barrier.
• Characterizing E171's physicochemical properties is essential for risk assessment.

Purpose of the Study:

• To characterize representative samples of E171 food additive.
• To evaluate and optimize sample preparation for particle size analysis.
• To assess variations in particle size, shape, crystal structure, and physicochemical form.

Main Methods:

• Standardized and validated methodologies were employed.
• Transmission electron microscopy (TEM) for particle size and shape distribution.
• Single-particle inductively coupled plasma mass spectrometry (spICP-MS) for elemental analysis.
• Evaluation and optimization of sample preparation protocols for TEM.

Main Results:

• Significant variations were observed in particle size and shape distributions among E171 samples.
• Crystallographic structures (rutile vs. anatase) and physicochemical forms differed.
• Optimized sample preparation enhanced the accuracy of TEM measurements.

Conclusions:

• The study highlights the heterogeneity of E171 materials.
• Results are vital for the risk assessment of E171 as a food additive.
• Findings support the European Food Safety Authority's guidance on nanomaterials in food.