^(60)Co-γ辐照蓝莓钙形态和亚细胞钙分布对果实硬度的影响

Effect of Calcium Morphology and Distribution on Fruit Firmness of Blueberries Irradiated by^(60)Co-γ

为了确定辐照处理后钙形态和亚细胞钙分布变化对冷藏蓝莓果实硬度的影响,本研究采用0.5、1.5、2.5 kGy辐照剂量处理蓝丰蓝莓,以未辐照处理为对照(CK),研究不同辐照剂量对果实硬度、果肉总Ca含量、不同溶解性Ca含量和Ca在亚细胞分布的影响,以及上述指标与冷藏蓝莓果实硬度的相关性。结果表明,0.5 kGy辐照处理对冷藏蓝莓果实钙的溶解性及其在亚细胞的分布没有影响,1.5和2.5 kGy辐照处理能够使蓝莓果实水溶性Ca含量升高,HCl溶性Ca和HAc溶性Ca含量下降,促进细胞器Ca^(2+)流向细胞质,并在冷藏期间逐渐向NaCl溶性Ca转变,被细胞壁吸附且累积,其中1.5 kGy辐照引起的钙形态和亚细胞钙分布变化与冷藏蓝莓果实硬度无关,但2.5 kGy辐照处理能够有效促进胞内Ca^(2+)向细胞壁迁移,对冷藏蓝莓果实硬度产生积极影响。本研究结果为蓝莓辐照保鲜研究提供了新思路。

To investigate the influences of calcium morphology and subcellular distribution on fruit firmness of blueberry irradiated by^(60)Co-γ,Bluecrop blueberry fruit were treated at irradiation doses of 0.5,1.5,and 2.5 kGy.Taking the unirradiated group as the control check(CK),influences of different irradiation doses on changes in fruit firmness,total Ca content in flesh,different soluble Ca content and Ca subcellular distribution were evaluated,as well as correlations of these changes with the firmness of refrigerated blueberry fruit.Results showed that irradiation treatment at a dose of 0.5 kGy had no impact on the solubility and subcellular distribution of calcium in frozen blueberries,but 1.5 kGy and 2.5 kGy could increase the content of watersoluble Ca,while decrease the contents of HCl-soluble Ca and HAc-soluble Ca.In addition,the flow of organellar Ca^(2+)to the cytoplasm was promoted,resulting in the transformation to NaCl-soluble Ca during cold storage,which gradually accumulated by the cell wall.The morphology and subcellular distribution of calcium induced by 1.5 kGy irradiation were not related to the fruit firmness of blueberries,while 2.5 kGy irradiation could effectively promote the transition of intracellular Ca^(2+)to the cell wall,which had a positive effect on the fruit firmness of frozen blueberries.