Abstract:
Synthetic food colorants have been widely used in the food industry for over a century due to their stability, consistency, and cost-effectiveness. However, a growing body of toxicological evidence has raised serious public health concerns regarding their continued use. Erythrosine (FDC Red No. 3, E127), a polyiodinated xanthene dye extensively used in confectionery, beverages, dairy products, pharmaceuticals, and cosmetics, represents a paradigmatic case of regulatory delay in the face of compelling scientific evidence.
This review critically examines the comprehensive toxicological profile of erythrosine, encompassing carcinogenic effects — evidenced by thyroid follicular cell adenomas and carcinomas in rodent models with clear dose-response relationships — endocrine-disrupting properties mediated through inhibition of Thyroid Peroxidase (TPO), displacement of thyroxine (T4) from transthyretin, and alteration of deiodinase enzyme activity. Additionally, neurotoxic effects are documented, including significant decreases in dopamine, serotonin, GABA, norepinephrine, and acetylcholinesterase levels, alongside increased oxidative stress markers and excitotoxicity via elevated glutamate. Genotoxic effects, including DNA strand breaks and induction of apoptosis in human peripheral blood cells, and allergenic properties including urticaria, angioedema, and respiratory symptoms, further complete this concerning profile. The protracted regulatory history of erythrosine is critically analyzed — from its provisional approval under GRAS status in 1960 to the U.S. FDA's landmark 2025 comprehensive ban on its use in food products, a decision that arrived nearly 35 years after its prohibition in cosmetics — illustrating the complex and troubling interplay between scientific discovery, industry influence, and public health policy.
In light of this urgent public health imperative, the transition toward natural colorants emerges not merely as a regulatory necessity but as a genuine technological challenge and opportunity for the food industry. This review evaluates a diverse and expanding array of plant-derived pigments as viable, health-promoting alternatives to synthetic dyes. Anthocyanins — extracted from radish, purple sweet potato, black carrot, elderberry, and grape skin — stand out for their wide color range, strong antioxidant capacity, and demonstrated anti-inflammatory and cardioprotective properties. Betalains from beetroot (Beta vulgaris) and Opuntia sp. offer remarkable stability across certain pH ranges and exhibit antioxidant, anti-tumor, and hepatoprotective activities. Carotenoids such as β-carotene, lycopene, and lutein, widely present in fruits and vegetables, provide yellow-to-red hues alongside well-established roles in eye health, immune function, and cancer prevention. Red gardenia pigment — composed primarily of crocins and crocetin — is highlighted as a particularly promising red substitute for erythrosine, given its color stability, water solubility, and potent antioxidant and neuroprotective bioactivity.
However, the adoption of natural colorants at industrial scale poses significant technological challenges, including sensitivity to heat, light, pH, and oxidation; lower tinctorial strength compared to synthetic dyes; and higher production costs. Addressing these limitations requires targeted food engineering solutions such as microencapsulation, nano-emulsification, and co-pigmentation strategies that enhance stability and bioavailability while preserving functional properties. The development of these technologies represents a critical investment in population health, particularly for vulnerable groups such as children, pregnant women, and individuals with pre-existing thyroid or neurological conditions who bear the greatest risk from chronic exposure to synthetic colorants.
This work advocates for an accelerated and decisive transition toward safer, more sustainable food coloring practices, urging a fundamental re-evaluation of regulatory frameworks worldwide to unequivocally prioritize public health over economic convenience, and calling upon the food science community to intensify research and innovation in the field of natural pigment technology.
Keywords: Erythrosine; FDC Red No. 3; Food Dye Toxicity; Carcinogenicity; Thyroid Disruption; Neurotoxicity; Natural Colorants; Anthocyanins; Betalains; Red Gardenia Pigment; Carotenoids; Microencapsulation; Food Safety Regulation; Sustainable Food Additives
