Typical defects following treatment with the test food additives. (A) Control; (B) Monosodium glutamate; (C) Sodium Benzoate; (D) Quinoline Yellow; (E) Brilliant Blue. Images were taken at 3 dpf. bc: body curvature; dy: darkened yolk; mio: microphthalmia; pe: pericardial edema; sy: swollen yolk; ry: ruptured yolk.

Dose–response curves showing embryonic survival (blue) and any malformation (red) upon 4-day treatment with different food additives. (A) Quinoline Yellow; (B) Sunset Yellow; (C) Azorubine; (D) Allura Red AC; (E) Brilliant Blue; (F) Sodium Benzoate; (G) Monosodium glutamate. Error bars showing 95% prediction intervals. Aspartame was excluded for not showing any observable effect.

Toxicological indices of the tested FAs. NOAECs are plotted against their European ADIs [34,35,36,37,39,40,41,42]. Food additives abbreviations as listed in Table 1; red color indicates aquatoxic, grey non-aquatoxic compounds. The bubble sizes represent the teratogenic index (TI); Substances without computable LC₅₀ and EC₅₀ (thus no TI) are displayed as small, borderless dots.

The 4 dpf embryos exposed showing different levels of darkened yolk (red arrow) in high salt solutions. (A) Control; (B) PBS 0.5X; (C) KCl 60 mM; (D) NaCl 85 mM; (E) MgSO₄ 125 mM.

Brilliant Blue treatment weakened the zebrafish embryonic yolk sac. Hatched embryos ((A–C) red arrow) had their yolk sac ruptured, while unhatched embryos remained intact ((C) black arrow). During hatching (D), the chorion injured the softened yolk, causing its rupture and finally killing the larva. Images were taken at 2-dpf and 5 g/L BB.

Prominent defects after four days of QY treatment to zebrafish embryos. Error bars showing 95% prediction interval.

Prominent phenotypes in zebrafish larvae after four days of exposure to SB. Error bars showing 95% prediction interval.

Azorubine stimulates embryo hatching even on day 1. Error bars showing 95% prediction interval.