Advisor(s)
Abstract(s)
The chestnut industry generates a large amount of by-products. These agro-industrial
wastes have been described as potential sources of phenolic compounds with high bioactive potential.
Therefore, we aimed to extract the phenolic compounds from chestnut by-products and assess their
antioxidant potential and evaluate their antimicrobial activity against multidrug resistant bacteria.
The individual phenolic compounds in the ethanolic extracts of chestnut shell, inner shell, bur,
and leaves were characterized by HPLC-DAD/electrospray ionization (ESI)-MS. The antioxidant
properties were determined by DPPH and ABTS assays. The minimum inhibitory concentration
(MIC) and the antimicrobial susceptibility was performed using the Kirby–Bauer disc di usion
method against 10 bacterial strains. The major phenolic compounds identified in the extracts were
trigalloyl-HHDP-glucose, gallic acid, quercetin, and myricetin glycoside derivatives. All chestnut
by-products presented promising antioxidant activity in both assays, with leaf samples the ones
presenting the highest antioxidant capacity. The inner shell’s extract was e ective against all
Gram-positive and two Gram-negative bacteria; nevertheless, all extracts showed antibacterial
activity. Staphylococcus epidermidis showed susceptibility to all extracts while none of the extracts was
able to suppress the growth of Escherichia coli and Salmonella enteritidis. Chestnut by-products are a
source of phenolic compounds with prominent antioxidant and antimicrobial activities. Nevertheless,
further studies should be conducted to assess the correlation between phenolic compounds and the bioactivities obtained.
Description
Keywords
Antimicrobial activity Antioxidant capacity Chestnut Industrial by-products Multidrug-resistant bacteria Phenolic compounds
Citation
Silva, Vanessa; Falco, Virgílio; Dias, Maria Inês; Barros, Lillian; Silva, Adriana; Capita, Rosa; Alonso-Calleja, Carlos; Amaral, Joana S.; Igrejas, Gilberto; Ferreira, Isabel C.F.R.; Poeta, Patrícia (2020). Evaluation of the phenolic profile of Castanea sativa mill. By-products and their antioxidant and antimicrobial activity against multiresistant bacteria. Antioxidants. ISSN 2076-3921. 9:1, p.