Abstract: Lactulose, also known as isomerized lactose, is a reducing disaccharide made from the dairy industry by-product lactose. Its concentrate is an important over-the-counter (OTC) drug that has a significant therapeutic effect on acute or chronic constipation and hepatic encephalopathy. The methods that have been developed to produce lactulose include the chemical method, β-galactosidase method and epimerase method. In recent years, the epimerase method has aroused extensive attention due to the high conversion rate it yields, which makes it a promising candidate for lactulose preparation although currently there exist some bottlenecks like the high proportion of epilactose as a by-product and the rather low enzyme activity. This article reviews the history and current status of research on the methods for lactulose production, in the hope of providing reference for basic theoretical research and industrialization in this field.

Key words: lactulose, preparation methods, constipation, hepatic encephalopathy, prebiotics

摘要： 乳果糖又名乳酮糖、异构化乳糖，是以乳业副产物乳糖为原料制备的一种还原性二糖，其浓缩液形式是一种重要的非处方药物，对急慢性便秘、肝性脑病等疾病具有显著疗效。乳果糖的生产方法包括化学法、β-半乳糖苷酶法、差向异构酶法等。近年来差向异构酶法因其高转化率受到广泛关注，是极具潜力的新一代乳果糖制备方法，但目前存在副产物依匹乳糖比例高、酶活力偏低等瓶颈问题。本文针对乳果糖制备方法的研究历史与现状进行综述，为该领域的基础理论及产业化研究提供借鉴。

关键词: 乳果糖, 制备方法, 便秘, 肝性脑病, 益生元