Microencapsulação por atomização do extrato do resíduo de seriguela e sua caracterização

Abstract

The agroindustrial residue of seriguela is rich in phenolic compounds, substances with antioxidant properties, however, in view of the sensitivity of these substances, it is necessary to employ technology with a view to promoting its stability and bioavailability, allowing its use in food and / or packaging. Thus, in order to evaluate the viability of the microencapsulation by atomization of the seriguela agroindustrial residue extract, the process conditions related to the entry temperature and maltodextrin concentration (10 DE) were investigated. The hydroethanolic extract was obtained from the dry residue and, to define the best microencapsulation conditions, the factorial design 22 was applied with three central points, with the concentration of maltodextrin (10%, 15%, 20%) as the independent variables. (100°C, 120°C, 140°C), the drying air flow rate of 28m³/h and the feed rate of 0.60mL/min were kept constant. Moisture content, water activity, hygroscopicity, apparent density, solubility, total phenolic content, antioxidant activity and encapsulation efficiency were the dependent variables. The phenolic profile of the extract, before and after the microencapsulation, was determined by high performance chromatography. The temperature and the concentration of maltodextrin exerted significant influence (p <0.05) on moisture, apparent density and total phenolic content, without influencing the other parameters studied. Microencapsulated with lower moisture content was observed when using maltodextrin in the concentration between 15 to 20%. The solubility was above 80%, regardless of the inlet temperature and maltodextrin concentration. Total phenolic content, in particular, was significantly influenced by the concentration of maltodextrin and little influence of the inlet temperature. Galician, p-coumaric and syringogenic acids were the major compounds present in the hydroethanolic extract, and there was a change in the qualitative and quantitative profile of the microencapsulated phenolics, thus, the 10 DE maltodextrin used as an encapsulating agent was not efficient to promote the stability of the compounds phenolics, in this way, it is evident the need of studies that aim at the optimization of the process.