Secagem de açaí branco por liofilização e em leito de jorro: influência da concentração e de diferentes agentes carreadores nas características físicas, químicas, bioativas e colorimétricas do pó obtido

Abstract

The objective of this study was to analyze how the use of four different carrier agents (modified starch, gum arabic, maltodextrin and hydrolyzed collagen) and different concentrations (10, 20 and 30%) influence the white açaí powder produced by lyophilization and in a bed of gush. Yield, moisture, total polyphenols, antioxidant activity, hygroscopicity, solubility, fluidity, color, chemical structure, and morphology were the responses evaluated. In freeze-drying, the yield of the process (≥ 75.40%) and the moisture content of white açaí powder (≤ 4.93 g 100 g- 1) did not differ statistically (p ≤ 0.05), regardless of the agent carrier used. In spouted bed drying, the addition of modified starch or hydrolyzed collagen promoted higher process yield (≥ 42.70%). However, the white açaí produced with hydrolyzed collagen was the only one that had a moisture content ≥ 6.00 g 100 g-1. In both drying processes, powders produced with modified starch were less soluble (≤ 48.96%), despite low hygroscopicity (≤ 13.73 g 100 g-1). Samples produced with maltodextrin or gum arabic showed higher levels of total polyphenols (≥ 8.52 mg EAG g-1) and antioxidant activity (≥ 42.75 μmol ET g-1). In addition, they were more soluble (≥ 94.36%), fluid (11 to 15% according to the carr index), and better preserved the original color of the pulp to the detriment of other formulations. The chemical structure of white açaí powders obtained with different carrier agents was like that of the pulp, indicating efficient encapsulation of bioactive compounds and good preservation of functional groups present in the original raw material, even after drying processes.