Effect of Curing at Different Temperatures on Phytohormone and Biochemical Composition of Onion 'Red Baron' during Long-Term Postharvest Storage
Effect of Curing at Different Temperatures on Phytohormone and Biochemical Composition of Onion 'Red Baron' during Long-Term Postharvest Storage
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DOI：
10.17660/actahortic.2010.877.92
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发表时间：
2010-11
期刊：
影响因子：
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通讯作者：
G. Chope;L. Terry
中科院分区：
文献类型：
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作者：
G. Chope;L. Terry
洋葱的长期储存能力是首先诱导休眠，然后抑制发芽的结果，但对这些过程的潜在生理机制的理解很少受到关注。在英国，球茎洋葱干燥和储存技术是基于20世纪70年代的研究，因此是在不同于今天使用的品种上进行的。因此，很可能改变当前的固化和干燥方法，例如，降低温度和持续时间，可以在节约能源和减少碳排放的形式中带来好处，同时仍然生产出令人满意的质量标准的洋葱。技术先进的冷藏和控制气氛（CA）储存系统可以长时间保持洋葱的可用性，但这是能源密集型的，并且部分依赖于芽抑制剂马来酰肼（MH）的使用。消费者和零售商要求消除食品中残留的压力越来越大，这意味着未来使用MH作为发芽抑制剂是不确定的。在田间给洋葱浇头，将其提升到仓库，然后在28°C下干燥6周的系统可能不适合现代品种，并可能对储存寿命产生不利影响。最近的研究表明，内源脱落酸（ABA）的下降与CA和常规气氛下的储存寿命有关，并且新鲜收获的球茎中ABA的浓度是养护前和养护后的两倍左右。因此，维持ABA浓度可以延长休眠期和贮藏期。本研究考察了低温（20、24和28℃，1℃贮藏）对洋葱球茎贮藏性和生化特性（包括ABA和其他激素）的影响。贮藏期（由芽生长决定）不受养护温度的显著影响。在所有温度下，蔗糖浓度增加，葡萄糖浓度降低，然而，在28°C腌制的洋葱中，葡萄糖和果糖的浓度立即减少，而在较低温度下腌制的洋葱中，蔗糖浓度较高。
Long-term storability of onions is a result of first, dormancy induction and then sprout suppression, but little attention has been given to understanding the underlying physiological mechanisms of these processes. In the UK, bulb onion drying and storage technology is based on 1970's research and therefore was carried out on cultivars different from those used today. Thus, it is likely that alterations to current curing and drying methods, e.g., a reduction in the temperature and duration, could deliver benefits in the form of energy savings and reduced carbon emissions, whilst still producing onion bulbs of a satisfactory quality standard. Technologically advanced refrigerated and controlled atmosphere (CA) storage systems can maintain availability of onions for prolonged periods, but are energy intensive, and depend partly upon the use of the sprout suppressant, maleic hydrazide (MH). Increasing pressure from both consumers and retailers to eliminate residues in food, means that future use of MH as a sprout suppressant is uncertain. The system of topping onions in the field, lifting into store and then drying at 28°C for 6 weeks may not be suited to modern cultivars and could adversely affect storage life. Recent work has shown that a decline in endogenous abscisic acid (ABA) was correlated with storage life in both CA and regular atmosphere, and that the concentration of ABA in freshly harvested bulbs was ca. double that measured before versus after curing. Thus, maintaining ABA concentration could extend dormancy and storage life. This study examined the effect of curing at lower temperatures (20, 24 and 28°C with subsequent storage at 1°C) on the storability and biochemical characteristics (including ABA and other hormones measured using LC MS/MS) of onion bulbs. Storage life (determined by sprout growth) was not significantly affected by curing temperature. Sucrose concentration increased, and glucose concentration decreased during curing at all temperatures, however, immediately after curing the concentrations of glucose and fructose were less in those onions cured at 28°C, whereas the sucrose concentration was higher in onions cured at lower temperatures.