Otimização da produção de microcápsulas de alginato de sódio e seu efeito sobre a atividade da β-galactosidase

Abstract

The inability to hydrolyze lactose contained in the milk, called lactose intolerance, affects approximately 75% of the world's population. This condition is caused by the deficiency or absence of the β-galactosidase enzyme production, which causes severe symptoms that make it impossible to fully digest this carbohydrate. Thus, researches are aimed at alternative methods to use this enzyme, responsible for hydrolysis to lactose, in order to overcome this deficiency. One of these techniques is microencapsulation, which protects and allows the reuse of β-galactosidase, but which still presents some obstacles such as the reduction of enzymatic activity. Thus, the present study aims to determine the best microencapsulation parameters of the enzyme β-galactosidase from Kluyveromyces lactis, microbial origin, aiming at the hydrolysis of lactose. The method involves the immobilization of the enzyme, the influence of calcium on the activity of microencapsulated β-galactosidase, the efficacy of the enzyme retention in sodium alginate spheres and the evaluation of the best conditions for the hydrolysis of lactose from a statistical design of Box and Behnken. For the statistical design, some independent variables were used, such as calcium chloride concentration, sodium alginate concentration and maturation time. The data was analyzed with the aid of the available program "Statistica 6.0". Under the conditions tested, the formation of the microspheres was more efficient using 1.2% (m/v) sodium alginate, 0.4% (m/v) calcium chloride, with 6 minutes of sphere maturation time. High concentrations of calcium may cause loss of catalytic activity of β-galactosidase, as well as small concentrations may have a negative effect on the production of microcapsules. The time for total lactose hydrolysis was determined to be ideal in the 120 a 180 minute range. Immobilized β-galactosidase had a good retention on sodium alginate beads, however the shelf life was relatively short approximately two days.