Allium cepa as a Model System for Assessing the Phytotoxicity of Food Dye Mixtures: An Integrated Analysis of Growth Rates and Physiological Parameters

Synthetic food dyes represent an important category of chemical contaminants with potential phytotoxic, genotoxic, and ecotoxic effects on living organisms and natural ecosystems. The present study aimed to evaluate the physiological effects induced by three commercial food dyes on the model organism Allium cepa, using the Allium test under hydroponic conditions. A total of 105 bulbs were exposed for 48 h to two different concentrations of each dye, for which gravimetric and physiological parameters, such as biomass, water content, mineral and organic composition, growth inhibition index, tolerance index, and relative growth rate, were subsequently analyzed. Statistical analyses revealed significant differences between batches for all evaluated parameters, indicating effects mainly dependent on the type of dye applied. The results suggest that exposure to synthetic food dyes causes disturbances in water balance, biomass accumulation and mineral homeostasis, confirming the phytotoxic potential of these compounds and the utility of the Allium test in the biomonitoring of chemical contaminants.