Guia de Qualidade da Cebola: Detectar Podridão e Mofo Preto

Onions are generally low-risk but can be treated with Maleic Hydrazide to prevent sprouting during storage or may harbor black mold (Aspergillus niger) which produces toxins.

1. The "Neck" Integrity Check:
Check the neck of the onion (where the leaves were attached). It should be tightly closed, dry, and hard. If the neck is soft, "spongy," or shows black powdery residue, the onion is either rotting or has a high concentration of fungal spores.

2. The Sprouting Test:
Naturally fresh onions will begin to sprout green shoots within 1-2 weeks at room temperature. If your onions never sprout even after months, they have been heavily treated with Maleic Hydrazide (a chemical growth inhibitor).

3. The Color and Skin Texture:
The outer papery skin should be crisp and have a natural, bright color (pink, red, or white). If the skin is "sticky," shriveled, or has an unnaturally "bleached" look, suspect chemical cleaning or sulfite treatment.

4. The Squeeze Test:
Gently squeeze the onion. It should be rock-hard. If it feels soft or has "liquid" under the skin, it is decaying from the inside out, often due to poor storage or chemical overdosing.