Características físicas e físico-químicas de partículas de alginato e quitosana obtidas por gelificação iônica

Abstract

Microencapsulation is a form of trapping active compounds in order to protect them from their environment, such as temperature, pH, oxygen and to allow their controlled release. The use of biopolymers in encapsulation systems has been used for food and biomedical applications as they are biocompatible, biodegradable and non-toxic. Pequi, of the species Caryocar coriaceum Wittm, is a fruit that can be found in Ceará in the Cariri region, where its oil is rich in substances of nutraceutical interest, such as oleic acid, flavonoids and carotenoids, acting as a natural source of antioxidants. Thus, in this work alginate and chitosan microparticles were produced in order to characterize their physical and physicochemical properties, such as the degree of swelling, particle size, sphericity and viscosity of the solutions used in the production of the spheres. The particles were produced using Büchi® Encapsulator B-395 by emulsifying drip containing alginate (A), pequi oil, Tween 80 and Span 80 in the gelling solution containing calcium chloride, chitosan (Q) and acetic acid. The spheres were produced in the proportions: A0,5%-Q1,5%; A1,0%-Q0,3%; A1,0%-Q1,5%; A1,0%-Q3,0%; A1,2%-Q0.0%; A1,5%-Q0,7%; A1,5%-Q2,5%; A2,5%-Q0,7%; A2,5%-Q2,3% and A3,0%-Q1,5% in m/v. To characterize them were performed swelling analysis by gravimetry, particle size and sphericity by light microscopy, as well as determination of the viscosity of the emulsions and gelling solutions. The particles presented swelling degree ranging from 17,86% to 48,33%. Regarding diameter, the values ranged from 874,10 to 1342,72 μm, with sphericity ranging from 0,596 to 0,971. The emulsions had apparent viscosity values between 0,073 and 1,989 Pa.s and the gelling solution from 0.033 to 1.504 Pa.s, these values being determined for a shear rate of 100 s-1. Thus, it was observed that the different proportions between alginate and chitosan led to variations between size and sphericity and that viscosity is a determining factor for these parameters.