木奈果肉褐变是酚类物质、多酚氧化酶与氧结合起酶促反应的结果．但酚、酶在果肉细胞中是区域化分布的，果实含Ｃａ量降低使膜透性增加，为酚、酶和氧接触提供了条件，果实缺Ｃａ是木奈果肉褐变的主要原因，通过提高果实的含Ｃａ量可有效地防止果肉褐变． Minamata browning is phenolic substances, polyphenol oxidase combined with oxygen enzymatic reaction results. However, phenol and enzyme are regionalized in the pulp cells. The decrease of Ca content in fruit leads to the increase of membrane permeability, which provides the conditions for the contact of phenol, enzyme and oxygen. Ca deficiency in fruit is the main reason of browning of Minamata fruit, Increasing the Ca content of fruit can effectively prevent browning of the pulp.