ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Internal atmosphere and watery scales in onion bulbs (Allium cepa L.).

Hoftun, H.;

Acta Horticulturae Year: 1993 Issue: No. 343 Pages: 135-140 Ref: 9 ref.

1993

บทคัดย่อ

Watery scales is a physiological disorder which develops in stored onion bulbs. Experiments were carried out to study gas exchange in onion bulbs to clarify whether changes in internal CO2 and O2 contents may result in watery scales. Onion bulbs (cultivars Jumbo and Laskala) were treated by the following methods in order to restrict gas exchange between the interior of the bulb and the external atmosphere: submerging the bulbs in water at 15 deg C for 0-8 days; injecting soyabean oil into the neck of the bulb prior to field curing or store drying for 1-4 weeks at 20 or 30 deg ; or covering the outer or centre parts of the bulb with vaseline. Blocking the neck of the bulbs caused a large increase in internal CO2 and a decrease in O2, indicating that the main gas exchange took place through the neck. During storage, 2 out of 5 onions developed watery scales when they had been totally submerged in water for one day. None of the bulbs with the neck above water had watery scales or rotted. After storage for 6 months at 0 deg , a high percentage (approx. 80%) of bulbs treated with soyabean oil had watery scales. When the outer or centre part of bulbs were covered with vaseline after the bulbs were cut 2 cm below the neck, differences in CO2 concentrations were observed, indicating restricted gas diffusion from scale-to-scale inside the bulbs. Watery scales were observed when CO2 concentration was >13% and O2 <4% in the internal atmosphere.