钙与苹果软化关系的研究初报

苹果软化过程中，果肉细胞壁分解释放的Ｃａ２＋主要分布于中层分解形成的空腔中；浸钙处理的果肉细胞中，Ｃａ２＋主要存在于质壁间隙及中层空腔中，并向细胞壁扩散以强化细胞壁，向细胞质扩散以降低各种软化因子；果肉细胞Ｃａ２＋含量降低，硬度降低，而呼吸强度、膜透性、可溶性果胶含量及多聚半乳糖醛酸酶（ＰＧ）和过氧化物酶（ＰＯＤ）活性增加；低温及浸钙处理条件下，果肉组织Ｃａ２＋含量高，软化程度低

The preliminary studies on the relationship of calcium and apple softening

During apple pulp softening,calciums released from degrading cell wall were distributed in the wnechage of middle lamella and gap between plasmalemma and cell wall.Calciums of the treated pulp distributed in the gap beteen plasmalemma and cell wall and further entered the interior of pulp by apoplast.Some calcium groups engaged in primary wall to strengthen the structure of cell wall and others were transported to cytoplast to inhibit some softng factors.After 30 days of storage,the content of calciums and firmness were decreased;respiration intense,membrance permeability,soluble pectin content,PG and POD activity were increased.Under the condition of lower temperature and treated by calcium,calcium content of pulp is higher,and the intensity of softening is lower.