Activated carbon production from wine industry residue for bioactive compounds recuperation and purification

Grape pomace (GP) (Vitis vinifera L.) is a solid by-product generated during the wine industrialization process. However, it has a commercial potential that should be investigated. Approximately 30% of all the grape’s mass destined for industrial production reaches the end of the process as residue, which is a persistent waste without practical application. Thus, it is necessary to develop technologies to reuse this waste, in this work activated carbon (AC) was synthetized for the recuperation and purification of bioactive compounds. The AC was obtained from the calcination (400 °C; 4 h) of GP and it was chemically activated with H3PO4 (85%; v v-1), in the ratio of 1:1 (m m-1), the material was later taken to a muffle furnace at 400 °C; 4 h for thermal activation. The adsorption tests were carried out using an extract of grape pomace (20 g L-1) obtained using hydroalcoholic solution (40:60 v v-1 water:ethanol) under agitation at 100 rpm for 24 h at 25 ºC, the initial concentration of gallic acid (GA) in the extract was approximately 198 mg L-1 and of catechin (CAT) was approximately 123 mg L-1. The AC in the proportion of 5 g L-1 were placed in contact with 50 mL of the extract under agitation at 100 rpm for 12 h for evaluation of the adsorption of GA and CAT in high-performance liquid chromatography with a photodiode array detector at a wavelength of 280 nm. The results of the adsorption process were expressed as adsorption capacity (qe) of GA and CAT (mg of bioactive compound g-1 of AC). For the adsorption assays using AC obtained from GP, qe values of 97 mg of GA g-1 of AC and 55 mg of CAT g-1 of AC were obtained for gallic acid and catechin, respectively. The process of obtaining AC from agro-industrial residues such as GP shows a potential application for the purification of bioactive compounds.