Microencapsulate Aspergillus niger peptidases from agroindustrial waste wheat bran: spray process evaluation and stability.

The aim of this work was to obtain microencapsulated stable Aspergillus niger peptidases by post fermentation spray drying. The enzymatic extract was evaluated before and after spray drying microencapsulation to verify the effects of five different process parameters on the extract enzymatic activity, i.e. air flow, extract feed rate, drying temperature, homogenising time and weight ratio of extract to encapsulation material. The optimal conditions were determined by desirability functions and experimentally confirmed. Additionally, the stability of the microparticles was assessed during 60 days at 4 degrees C, 25 degrees C and 40 degrees C. The results revealed that the microparticles stored at 4 degrees C retained approximately 100% of their proteolytic activity at nine days of storage. Considering the industrial adaptation of the bioprocess and the prospect of commercial application of the proteases, the evaluation of different parameters for drying enzymes is required as a valuable alternative to obtain biotechnological products with high added value.