Otimização da extração de ácidos clorogênicos do coproduto de Ilex paraguariensis e incorporação em fibras de amido de trigo obtidas por electrospinning

Abstract

The co-product generated during the pruning of Ilex paraguariensis has shown high potential due to its high concentration of phenolic compounds, mainly chlorogenic acids. There are still few studies on the extraction of these compounds from the coproduct, as well as their use in the food industry. Therefore, it is necessary to study ways to sustainably extract and encapsulate these compounds to avoid degradation. In this study, a multivariate design was used for the extraction of chlorogenic acids present in the co-product of Ilex p.I. paraguariensis using a green method. The obtained extracts were evaluated by HPLC-ESI-QTOF-MS, obtaining 7.36 g of chlorogenic acids (5-caffeoylquinic, 3-caffeoylquinic, 4-caffeoylquinic, 3,4- dicaffeoylquinic, 3,5-dicaffeoylquinic and 4 ,5-dicaffeoylquine) per 100 g of co-product under optimal extraction conditions. This extract was evaluated for its antioxidant capacity against DPPH and ABTS radicals and showed 94.35% and 99% inhibition, respectively, and a reducing capacity of 65.6 mg/100 g. In the in vivo toxicity test using Galleria Mellonella larvae, the extract showed a lethal dose (LD 50) at a concentration of 5.8 g/kg, which can be classified as slightly toxic. After obtaining the aqueous extract, the compounds present in the co-product of Ilex p.I. paraguariensis in ultrafine wheat starch fibers using the electrospinning technique, in which parameters of the polymer solution and the process for obtaining the fibers were tested. Extract concentrations of 5, 10 and 15% (w/w) in polymeric solutions of 15% wheat starch in 75% formic acid were used. Polymeric solutions showed higher viscosity and electrical conductivity with increasing co-product (1.181 to 1.259 cP and 2.69 to 3.45 mS/cm, respectively). The ultrafine fibers had an average diameter of 195 nm to 218 nm, with continuous, smooth and uniform morphology. The maximum encapsulation efficiency occurred at a concentration of 5% (90.8%), with a decrease being observed as the concentration increased. The membranes showed greater hydrophilicity as the extract concentration increased and greater stability when encapsulated, through thermogravimetric analysis. The ultrafine fibers exhibited antioxidant activity against free radicals ABTS, DPPH. Ultrafine wheat starch fibers encapsulated with Ilex p.I. paraguariensis showed positive characteristics and are promising in the food area, requiring further studies of its application.