Further work is needed to understand why leathery scale develops and how it can be minimized. Leathery scale was not affected by the treatments examined in this study. The results explained the induction of translucent scale. Internal CO 2 concentration, as high as 22.3%, occurred after combined dropping and pressure treatments. Dropping and pressure treatments produced more translucent scale but had no effect on leathery scale. Weak symptoms of translucent scale could disappear in storage, but usually symptoms became more severe after long-term storage. Normal cultivation of onion and handling of bulbs resulted in low occurrence of disordered bulbs. Gas flux was related to need of O 2 in respiring tissue and to problems of adverse internal atmosphere and development of disordered scales. Transport of gas through the neck region was 10–20 times higher than transport through the scale. Dry scale and epidermis of fleshy scale had very low oxygen permeability. Cook over a medium flame until the onions become translucent. Leathery scale tissues had a pH around 3.5 and a rise in ethanol content, indicating anaerobic respiration. Learn how to use translucent in a sentence with 170 example sentences on YourDictionary. A rise in pH occurred in translucent scales with weak symptoms followed by a reduction in pH. A clear reduction in electrical conductivity of translucent tissue was measured, indicating leaching. Translucent scale generally occurred in the middle and upper parts of the outer two fleshy scales but could include the entire bulb. Internal bulb atmosphere, gas flux, and gas permeability (of O 2) of onion scale and tissues were measured to explain why damage occurred. Bulbs were exposed to handling treatments leading to increased respiration and/or reduced gas exchange from the interior of bulbs to the outside atmosphere. The disorders were linked to disturbances in gas exchange of bulbs with high internal CO 2 and/or low internal O 2 levels. Symptoms of watery scale were clarified based on visual appearance, tissue pH, electrical conductivity, and contents of ethanol, lactic acid, and acetic acid. Watery scale includes the following categories of disorders: leathery scale, which appears as thick, dark scales between outer dry and inner fleshy scales, and translucent scale, which appears as glassy, firm fleshy scales further into the bulb. Watery scale (translucent and leathery scale) is a postharvest problem in our area causing loss of yield and quality. After a field-curing period the bulbs are put into storage and dried at 25–30☌ until the neck is completely dry before the temperature is gradually reduced to 0☌ for long-term storage. In Northern Europe, onion ( Allium cepa L.) is grown from sets planted out in early May and lifted in early September.
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