ULTRASOUND PROCESSING OF ENZYMES WITH INDUSTRIAL INTEREST

Enzymes are applied in various industrial segments, but their use in large scale can be limited by high costs and low stability. Different alternatives are being developed to minimize these limitations, being ultrasound an alternative. Therefore, the objective of this work was to evaluate the effect of ultrasound on the hydrolysis promoted by different enzymes of industrial interest (Cellulase, Pectinase, α-amylase and invertase). The suspension containing the substrates (carboxymethylcellulose -0.25%w/v, pectin -1%w/v, starch -1%w/v, and sucrose –60%) and enzymes (invertase –0.1g, α–amylase –0.2g, Cellulase and pectinase –2g per 1kg of substrate) were added directly into the ultrasonic bath tub, being processed at 25kHz/22W/L up to 7 hours in different conditions: 25 °C (Cellulase, Pectinase, α -amylase) or 40 °C (invertase), pH 4.0 (Cellulase, Pectinase, α-amylase) or 5.0 (invertase). As a control, the reactions were carried out in a water bath. The absorbance was measured by the reductive sugar method by the reaction with DNS. The reaction was demonstrated by the increase in absorbance due to the release of reducing sugars from the substrate, which were measured by the reaction with DNS. No difference was observed in the hydrolysis process with and without ultrasound for the enzymes cellulase, pectinase and α-amylase. For invertase, however, the hydrolysis was accelerated when the reaction was performed using ultrasound, with a 24% increase in the reaction rate (first-order kinetics). Acoustic cavitation generates a large amount of energy, which results in propagating shockwaves and shear forces, causing strong turbulence within the surroundings. This reduce the limiting barrier of diffusion between enzyme and substrate, which increases the mass transfer during the reaction. Therefore, the results amplify the use of ultrasound since this technology can improve the performance of some enzymes, an interesting result at an industrial level.