Desidratação por atomização de cálices de Hibiscus sabdariffa

Abstract

Hibiscus sabdariffa is a plant species of the family Malvaceae and belongs to the class of dicotyledons. Popularly known as rosela is a plant with therapeutic properties, and consumed in several parts of the world. The most used part is the chalice, by the content of anthocyanins, which is more highly perishable, which provides greater stability as well as its beneficial capacity. Spray drying is a process used in heat sensitive foods, since it has produced particles with low intensity over time, favoring the retention of some properties of the product, such as nutritional constituents, bioactive and aromas. Thus, the study aims at the extraction methods of anthocyanins of Hibiscus sabdariffa aiming at a greater extraction; obtain extract of Hibiscus sabdariffa powder by the atomization process and its physical and physical functions. They were designed for the use of methods of thread extraction, maceration for 24 hours, simple turbolization, turbolization with fractional filtration and turbolization with ultrasonic application. At this moment a kinetic was performed with different extraction times for the optimal process time arrangement. In all methods, distilled water and acidified water (2% citric acid) are used as the solvent. To the dehydration of the roselle extract by atomization the carriers of gum arabic, chitosan and maltodextrin in the ratio of 1: 9 (driver: extract of H. sabdariffa) were used, obtaining seven suspensions. The variables of the extraction process together were defined by a simplex centroid experimental design. As suspensions were used employing different diameters of nozzle sprinkler (0.7mm, 1.0mm and 1.2mm). The yield of the process and the properties of the moisture powder, water activity, hygroscopicity, solubility, anthocyanins, antioxidant activity and color were determined. Turbolization with ultrasonic application for 20 min., with acidified water as solvent favored the highest extraction of anthocyanins. At atomization, the mixture of gum arabic and chitosan with a spray nozzle of 1.0 mm in diameter provided a powder product with higher anthocyanin content, higher antioxidant activity and yield. Regardless of the formulation, all powder extracts presented low water activity, high solubility and predominance of burgundy color. It was concluded that the turbolization with ultrasonic application for 20min with acidified water was the form that provided extracts with higher levels of anthocyanins and antioxidant activity, and that in the atomization process, the carrier agents and the diameter of the sprinkler nozzle influenced the yield and on the chemical and antioxidant properties of the H. sabdariffa extract supplying microparticles with high anthocyanin content.