请翻译：目前制备异麦芽酮糖醇的主要方法是采用经蔗糖异构酶催化蔗糖产生的异麦芽酮糖作为加氢原料在高温高压的条件下经过雷尼镍催化剂的作用被加氢转化为异麦芽酮糖醇。然而异麦芽酮糖醇生产过程中存在副产物多、反应条件严苛、反应步骤冗长复杂产品分离纯化难度大的等问题。

Currently, the main method for preparing isomaltulose is to use isomaltulose produced by sucrose isomerase-catalyzed isomerization of sucrose as a hydrogenation feedstock. Under high temperature and high pressure conditions, it is hydrogenated and converted to isomaltulose alcohol through the action of Raney nickel catalyst. However, there are problems in the production process of isomaltulose alcohol, such as the presence of multiple by-products, strict reaction conditions, lengthy and complex reaction steps, and difficulty in product separation and purification.