Cold storage has been recommended to preserve onion bulbs, but producers always have doubts about its quality, during this period and when they are exposed to environmental conditions. We evaluated the onion bulbs quality, cv. Superex, packed in plastic fiber bags, during storage under 10-12°C (68% RH) during 91 days. After 1; 16; 31; 61 and 91 days, samples were transferred to environmental conditions (22°C, 59% RH). Onion bulbs were evaluated for fresh mass, appearance and occurrence of rot, internal color, lightness, color or hue angle and chromaticity, alliinase activity, soluble solids and titratable acidity content. Bulbs under environmental condition lost more fresh mass than those stored under refrigeration and maintained acceptable quality for 38 days. Only bulbs stored during 91 days presented bad appearance when transferred to environmental conditions. Bulbs showed tendency of internal yellowing, without significant changes in soluble solids and titratable acidity. During the cold storage period, the pungency increased from "pungent" to "hot pungent" and remained stable during ambiental conditions.
Allium cepa; refrigerated storage; pungency; alliinase
