Inulinase

Inulinase is an enzyme that catalyzes the hydrolysis of inulin, a polysaccharide composed of fructose units linked by beta-(2→1) glycosidic bonds. Inulin is found in various plants, such as chicory and Jerusalem artichoke, and serves as a storage carbohydrate. Inulinase breaks down inulin into its constituent monosaccharides, primarily fructose and glucose, and also produces fructooligosaccharides (FOS) depending on the specific type of inulinase and reaction conditions.

There are two main classes of inulinases based on their mode of action. Exoinulinases cleave inulin from the non-reducing end, releasing single units of fructose. Endoinulinases act internally, cleaving the inulin chain at random positions, leading to a mixture of shorter oligosaccharides and monosaccharides. Some inulinases exhibit both exo- and endo-activity.

Inulinases are widely distributed in nature, found in bacteria, yeasts, fungi, and plants. Industrially, inulinases are produced mainly by microbial fermentation, with Aspergillus species being common sources. These enzymes have significant commercial applications. They are used in the food industry to produce fructose syrups, which are sweeter and have a lower glycemic index than sucrose. Inulinase is also employed in the production of fructooligosaccharides (FOS), which are recognized as prebiotics, promoting the growth of beneficial gut bacteria. Furthermore, inulinases are utilized in the pharmaceutical industry and in analytical chemistry for the determination of inulin content. Research is ongoing to explore novel applications and improve the efficiency and stability of inulinase enzymes.