betaamylase

Beta-amylase, or β-amylase, is an enzyme that catalyzes the hydrolysis of starch and related polysaccharides from the non-reducing ends, releasing maltose as the main product. It is an exo-acting enzyme, in contrast to endo-acting enzymes that cut internal bonds.

The enzyme acts on α-1,4 glycosidic bonds in amylose and amylopectin but stops at branch points where α-1,6 bonds occur, so it cannot fully degrade highly branched starch on its own. Consequently, complete starch conversion typically requires debranching enzymes and/or other amylases to process the branches.

Beta-amylase is found in a variety of organisms, including plants, fungi, and some bacteria. In plants, it plays a key role during seed germination, mobilizing stored starch to support growth. It is also a significant component of malt used in brewing and other grain-based processes, and microbial beta-amylases are employed in industrial starch processing.

Industrial and practical uses of beta-amylase include the production of maltose-rich syrups and enhancement of fermentable sugars in brewing and ethanol production. In baking and food processing, beta-amylase can influence sweetness and fermentability of starch-derived sugars, depending on formulation and processing conditions.

Properties and regulation: beta-amylase operates best under mildly acidic conditions and at moderate temperatures, with activity influenced by pH, temperature, and the presence of inhibitory products such as maltose at high concentrations. As with many enzymes, its activity is tailored to the biological context of its source and application.