Stable, environmentally friendly and inexpensive biocatalysts for obtaining important ingredients applicable in the food industry

Abstract

Clays are naturally occurring, environmentally friendly, chemically inert, thermostable, inexpensive resources that are easily modified into materials with tailored properties. As such, they can be used as suitable supports for enzyme immobilization and application in the food industry. Natural polysaccharides starch, xylan, pullulan, and its derivatives obtained by the action of enzymes, have numerous potentials for food industrial applications. In this work the enzyme supports were prepared from bentonite from Coal mine "Bogovina", Serbia by acid activation (AA), pillaring (P), and pillaring followed by acid activation (PAA). The characterization of the obtained materials included chemical and phase composition, surface acidity, and textural properties. After characterization, -amylase from Bacillus paralicheniformis (BliAmy), commercial xylanase from Sigma-Aldrich (Xyl), and pullulanase from B. paralicheniformis (BliPull) were immobilized on bentonite based supports by 24 h adsorption at 25 °C. The obtained biocatalysts BliAmy-AA (106 IU/g), Xyl-P (74 IU/g), and BliPull-PAA (45 IU/g) showed very good storage stability with the activity preserved after 4 weeks of testing. Products of hydrolysis were detected by TLC and indicate a promising application in the food industry.