Activated carbon bleaching for MOAH mitigation in palm oil: a multi-parameter laboratory-scale study using...

Area of Science:

• Food Chemistry
• Analytical Chemistry
• Food Safety

Background:

• Mineral oil hydrocarbons (MOH) are food contaminants found in edible oils.
• Mineral oil aromatic hydrocarbons (MOAH), a sub-fraction of MOH, are a concern due to potential genotoxicity, especially those with three or more aromatic rings.
• Activated carbon (AC) bleaching is a potential mitigation method for MOAH in edible oils.

Purpose of the Study:

• To quantitatively investigate the effect of AC bleaching on MOAH subclasses in real edible oil matrices.
• To assess the influence of AC type, dosage, and temperature on MOAH mitigation.
• To evaluate the impact of aromatic ring number and alkylation degree on MOAH adsorption.

Main Methods:

• Analysis of MOAH subclasses in spiked palm oil using HPLC/GC×GC-FID.
• Application of a Doehlert experimental design and response surface methodology.
• Testing two types of AC at varying dosages (0.3-1.8%) and temperatures (60-100°C) under constant pressure and contact time.

Main Results:

• AC bleaching significantly mitigated MOAH with three or more aromatic rings, with a reduction of approximately 25-30%.
• Adsorption of MOAH with 1-2 aromatic rings was significantly lower.
• AC concentration was the most influential factor, with higher dosages leading to greater MOAH reduction.
• Temperature influenced MOAH mitigation in an AC-type-dependent manner.
• Higher alkylation degree reduced MOAH affinity for AC.

Conclusions:

• AC bleaching is an effective method for reducing potentially genotoxic MOAH in edible oils.
• The effectiveness of AC bleaching is dependent on AC dosage, temperature, and MOAH structure (ring number and alkylation).
• Further research can optimize AC bleaching processes for MOAH removal in food production.