The potential of lignin extracts from sugarcane bagasse to scavenge reactive oxygen and nitrogen species
Tuesday, April 29, 2014
Exhibit/Poster Hall, lower level (Hilton Clearwater Beach)
Lívia Beatriz Brenelli1, Fernanda Mandelli1, Eliseu Rodrigues2, Adriana Zerlotti Mercadante2, George Jackson de Moraes Rocha1 and Fabio M. Squina3, (1)Basic Research, Brazilian Bioethanol Science and Technology Laboratory, Campinas, Brazil, (2)Department of Food Science, Faculty of Food Engineering, State University of Campinas, Campinas, Brazil, (3)The Brazilian Bioethanol Science and Technology Laboratory (CTBE), Campinas, Brazil
Lignins are by-products from biomass-based industries, non-toxic, inexpensive and available in large amounts. Due to the high content of diverse functional groups and its phenylpropanoic structure, lignin can act as a strong antioxidant. However, the scavenger capacity of the lignin depends on the plant species, as well as the extraction and separation processes for lignin fractionation. The aim of this work was to evaluate the antioxidant capacity of lignin extract produced after steam explosion and alkaline treatment of sugarcane bagasse (AT) and the supernatant produced after acid precipitation of AT, dubbed as lignin waste fraction (WL). The total phenolic content and the scavenge capacity against reactive oxygen (ROO and H2O2) and nitrogen (ONOO-) species of soluble fractions of AT obtained at different pH values (12, 10, 8, 6, 4 and 2) and of WL were evaluated. The chemical characterization was performed by UV, FT-IR and GC-MS/MS and H-NMR. AT-pH2 and WL exhibited the highest scavenging capacities against all species tested (10,17 ± 0,7 mmol TE.g-1 of lignin and 11,45 ± 1,28 mmol TE.g-1 of lignin for ROO, IC30=14,9 µg.mL-1 and IC30=16,6 µg.mL-1 for H2O2, and IC50=2,27 µg.mL-1 and IC50=1,61 µg.mL-1 for ONOO-, respectively). These two lignin fractions also showed lowest content of phenolic hydroxyl groups, along with molecules with lower molecular weight, when comparing with other fractions.  Thus, suggesting that WL and AT-pH2 have potential for development of value-added applications, in particular in pharmaceutical and food industries.