Drying study and phytochemical profile of the aqueous extract of the scaly leaf bulb of Allium cepa L (var.roxa)

Abstract

The objective of this study was to evaluate the phytochemical profile, predict drying kinetics, and quantify the content of total phenolics and flavonoids present in the aqueous extract of the bulb of scamiform leaves of Allium cepa L. The plant material was collected in the municipality of São Luís (MA). For the preparation of the aqueous extract, the cold maceration process was used using distilled water as a solvent. For the study of the drying kinetics, 10 g of the material in natura was submitted to a convective air oven at 45 °C/4h. The statistical parameters were determined by nonlinear regression using the Statistica 10.0software, using the Quasi-Newton method. To determine the total phenolic content, the Folin-Ciocalteu methodology was used. And for the total flavonoids, the aluminum complexation assay was used. The determination of phenolics and total flavonoids revealed significant quantities in the extract, with values of 106.54 mg EAT g-1 and 26.36 mg EAT g-1, respectively. According to the prediction of the statistical data, it was verified that the mathematical methods of Midilli-Kucuk and Verma proved to be adequate to describe the drying process of Allium cepa L. Through the results obtained, the mathematical model was determined for the drying kinetics of the squamous leaf bulb Allium cepa L, in addition to attesting the presence of secondary metabolites, thus making the product fit for biologically active activities.