Chapter 16 - Production of lactulose from cheese whey

Abstract

Whey is a major waste generated by the dairy industry. Lactose makes up around 70% of total whey. One alternative to whey valorization is lactulose synthesis from whey lactose. Currently, prebiotic lactulose synthesis receives a higher interest and is being studied intensively due to its functional characteristics and is also part of whey or lactose valorization. Lactulose can act as a prebiotic because lactulose is not processed by the human digestive system, thus passing through the stomach and the small intestine without undergoing degradation. Lactulose can also be used to treat constipation and hepatic encephalopathy, as an antiendotoxin and antidiabetic agent, to treat inflammatory bowel diseases, etc. Lactulose synthesis can be done by isomerization or transgalactosylation where the enzymatic isomerization shows enhanced yield and selectivity. From the perspective of reaction yield and ease of separation, lactulose synthesis through cellobiose 2-epimerase-catalyzed isomerization in the enzymatic membrane reactor is a promising approach. Following this strategy, such industrial preparative chromatography is the only main unit operation to separate lactose and lactulose.