What is the Difference Between Alpha and Beta Amylase?

Alpha and beta amylase are both enzymes that catalyze the hydrolysis of starch into sugars, but they have different functions and characteristics:

Alpha Amylase:

• Acts on random locations along the starch chain.
• Releases lower molecular weight dextrins from starch.
• Commonly found in human saliva and pancreatic juice, helps in digestion.
• Produced by Bacillus licheniformis and used in starch production.
• Stable in hot, watery mashes and active between 145-158°F (63-70°C).
• Requires calcium as a co-factor.

Beta Amylase:

• Acts from the non-reducing end of the starch chain to facilitate the breakdown of large polysaccharides.
• Promotes further hydrolysis of dextrins to maltose, which can be used as a fermentable sugar by yeast.
• Associated with seed germination (during malting) and fruit ripening.
• Found in seeds of higher plants, bacteria, and fungi.
• Active between 131-149°F (55-65°C).

In the context of beer brewing, alpha amylase is responsible for breaking down large, complex starch molecules into smaller, soluble molecules, while beta amylase is the main producer of fermentable sugars, breaking down starch systematically to produce maltose. The activity of these enzymes can be influenced by the mash temperature and pH, allowing brewers to manipulate the types and amounts of sugars extracted into the wort.

Comparative Table: Alpha vs Beta Amylase

Alpha and beta amylase are two enzymes involved in the breakdown of starch into sugars. Here are the key differences between them:

Both enzymes are naturally produced in malted barley during the malting process and are used in the mashing stage of beer brewing. They have different substrates, products, optimal pH, and optimal temperature ranges, which can be manipulated to achieve different results in the brewing process.