知识与财富的链接
为了研究急速降温处理与缓慢降温处理时,FAD与LOX基因表达量对鸭梨果心褐变的影响,以适时（9月中旬）采收鸭梨为材料,对鸭梨贮藏中果心部位脂肪酸含量、ω-3脂肪酸去饱和酶（ω-3 fatty acid desaturase,ω-3FAD）基因表达量、脂氧合酶（lipoxygenase,LOX）活力及基因表达量进行测定。结果表明：贮藏期间,急速降温处理组果心褐变指数明显高于缓慢降温处理组,并且急速降温处理组受到低温胁迫,机体产生抗冷机制,导致果心不饱和脂肪酸（尤其是亚麻酸）含量,ω-3FAD1、FAD2表达量与LOX活力均有不同程度的增加,并且低温激活LOX基因表达,加速膜脂过氧化,降低鸭梨品质。因此,对于适时采收的鸭梨,应采取缓慢降温的方式进行贮藏,以提高鸭梨贮藏品质。
In order to explore the effects of rapid and slow cooling on ω-3 fatty acid desaturase (ω-3FAD) and lipoxygenase (LOX) gene expression and core browning in Yali pears, Hebei grown Yali pears (Pyrus bretschneideri Rehd cv. Yali) were chosen to determine the contents of fatty acids and the gene expression and activities of FAD and LOX. The results showed that the core browning index of the fruits subjected to rapid cooling was significantly higher than that of those subjected to slow cooling during storage. Cold resistance occurred in the rapid cooling group, resulting in increased contents of unsaturated fatty acids, up-regulated expression levels of ω-3FAD1 and FAD2, and enhanced activities of LOX. Moreover, low-temperature stress activated the expression of LOX gene, accelerated membrane lipid peroxidation, and reduced fruit quality. Therefore, timely harvested Yali pears should be cooled slowly in order to improve the storage quality.
