ABSTRACT
Dairy industry is producing a large amount of liquid wastes, mainly whey and whey permeates. These by-products contain lactose, proteins, fats, and minerals, with high BOD and COD values, due to the lactose molecules. Therefore, lactose is undergoing some processes to produce lactose-derived compounds, such as lactosucrose, epilactose, tagatose, and lactulose. Lactu-lose is recognized as a prebiotic disaccharide with versatile applications in the food and medical sciences. It is mainly synthesized from lactose by several chemical isomerization methods. However, due to the use of noxious compounds and high production costs of this route, the food industry has been motivated to introduce new green and low-cost synthesis methods for lactose to lactulose conversion. In this way, enzymatic synthesis is currently gaining a lot of attention to produce lactulose from pure and also crude lactose sources, such as whey and whey permeates. Lactulose is used in medical science to treat constipation, hepatic encephalopathy, and other implications. In food industry, it is applied as a prebiotic and a functional ingredient. This book chapter therefore focuses on the different lactose to lactulose conversion methods. The purification techniques, the potential food/pharmaceutical applications, and bioactive-derived compounds of lactulose are also discussed in the chapter.
