Microencapsulação por spray drying de Campomanesia sp. com diferentes bicos aspersores e incorporação de polpa verde de bocaiuva como agente carreador para retenção de compostos bioativos

Abstract

Dehydration by atomization minimizes the loss of bioactive compounds and improves the characteristics of the powdered product, increasing the applicability. The objective of this study was to obtain Guavira pulp (Campomanesia sp.) powder by the atomization process with the addition of dehydrated pulp of the green fruit of Bocaiuva (Acrocomia aculeata), in this study called PDB, as a carrier agent. Initially, it was evaluated the influence of the addition of 6% of PDB with the mixtures of the carrier agents maltodextrin, gum arabic and chitosan, and the diameter of the sprinkler nozzle in the yield, solubility, hygroscopicity and retention of vitamin C. In this first stage, the spray nozzle of 1.0 mm in diameter and the mixture of the PDB with gum arabic were defined as process conditions because they provide greater retention of vitamin C. From the selected conditions, particles with PDB and gum arabic were produced as carrier agents: 6% of PDB (BD1), 9% of PDB (BD2) and 12% of PDB (BD3). The obtained particles were evaluated for the physical characteristics, rehydration capacity, phenolic compounds, vitamin C and antioxidant activity. The samples showed low moisture content (< 5%) and water activity (< 0.6). The addition of PDB favored the formation of microparticles, diameter less than 100 μm, in assays BD2 and BD3. The diameter of the particles directly influenced the solubility, wettability, dispersibility, density, porosity and flowability of the powders. The morphology of the powders showed the formation of particles of spherical shape and without cracks. The use of PDB as a carrier agent in the assays BD1 and BD2 favored the higher retention of vitamin C, however, the test with higher content of PDB (BD3) showed greater retention of phenolic compounds. The blend of the two carrier agents was efficient in the microencapsulation of bioactive compounds and resulted in microparticles with high antioxidant capacity. Finally, we conducted a study of color stability, vitamin C, phenolic compounds and antioxidant activity of these particles (BD1, BD2 and BD3) stored for seven days in different pH grids solutions. It was estimated and the half-life time and the decimal reduction time of vitamin C. The BD3 sample, with higher amount of PDB, showed lower degradation of vitamin C in storage. Bioactive stability was estimated up to 61 days for half-life and 193 days for the decimal reduction time. Given these findings, the green fruit of dehydrated Bocaiuva presents with potential of carrier agent in the atomization of Guavira pulp partially replacing the gum arabic to obtain microparticles with stability of bioactive and longer time of shelf life. Therefore, these results demonstrate that the Guavira pulp microparticles with addition of Bocaiuva as wall material in the atomization process can be used as vitamin C supplement or incorporated into food products such as yoghurt, milk drinks and juices. In addition, future research can be carried out in order to study the influence of Bocaiuva as a wall material to protect other substances by the atomization process, or also its use in other microencapsulation techniques.