Author:

Keywords:

Amylase, Action pattern, Hydrolysis, Malto-oligosaccharide forming alpha-amylase, Science & Technology, Physical Sciences, Life Sciences & Biomedicine, Chemistry, Applied, Food Science & Technology, Nutrition & Dietetics, Chemistry, PSEUDOMONAS-STUTZERI, BACILLUS-STEAROTHERMOPHILUS, RHEOLOGICAL PROPERTIES, FORMING AMYLASE, ACTION PATTERN, PURIFICATION, SACCHAROPHILA, IMPACT, SUGARS, Bacterial Proteins, Biocatalysis, Clostridium thermocellum, Enzyme Stability, Geobacillus stearothermophilus, Hot Temperature, Maltose, Pseudomonas, Starch, alpha-Amylases, beta-Amylase, Food Science, 3006 Food sciences

Abstract:

Maltogenic α-amylase from Bacillus stearothermophilus (BStA) is widely used as bread crumb anti-firming enzyme. A maltotetraose-forming α-amylase from Pseudomonas saccharophila (PSA) was recently proposed as alternative, hence the need to compare both exo-acting enzymes with some endo-action component. A purely exo-acting thermostable β-amylase from Clostridium thermosulfurogenes (CTB) was included for reference purposes. Under the experimental conditions used, temperature optima of the enzymes are rather similar (60-65 °C), but temperature stability decreased in the order BStA, PSA and CTB. The action of the enzymes on different substrates and their impact on the rheological behaviour of maize starch suspensions demonstrated that, while CTB acts exclusively through an exo-action mechanism, BStA displayed limited endo-action which became more pronounced at higher temperatures. PSA has more substantial endo-action than BStA, which is rather temperature independent. This is important for their impact in processes such as breadmaking, where temperature is gradually increased.