Banca de QUALIFICAÇÃO: YINETH RUÍZ GARCÍA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : YINETH RUÍZ GARCÍA
DATA : 11/05/2018
HORA: 09:00
LOCAL: Embrapa Agroindústria de Alimentos
TÍTULO:

Influence of process conditions on extraction of bioactive compounds from grape skin Alicante Bouschet (Vitisvinifera L.)

PALAVRAS-CHAVES:

extraction, bioactive compounds, antioxidant capacity, optimization, grape skin, Alicante Bouschet

PÁGINAS: 23
GRANDE ÁREA: Ciências Agrárias
ÁREA: Ciência e Tecnologia de Alimentos
RESUMO:

In this work solid-liquid extraction of bioactive compounds from grape skin cultivarAlicante Bouschetby using response surface methodology (RSM) was studied. Effects of process conditions (temperature, ethanol concentration and citric acid concentration) on total phenolic compounds, anthocyanins and antioxidant capacity of grape skin extracts (ABTS^●+ and ORAC methods) were evaluated. Ethanol concentration and temperature were found to be significant on extraction of total phenolic compounds and on antioxidant capacity. The extraction of monomeric anthocyanins was only affected by ethanol concentration. Addition of citric acid to extractive solution did not influence the extraction of monomeric anthocyanins and antioxidant capacity of grape skin extracts.However, a slight increase in content of total phenolic compounds was observed when larger concentrations of citric acid were used. Most favorable extraction conditions were identified as 40 ° C temperature, 50 % v/v ethanol concentration and 2 % m/v citric acid concentration.Total phenolic content presented a high positive and significant correlation (p <0.05) (r = 0.906) with antioxidant capacity measured by ABTS^●+ method. On the other hand, antioxidant capacity measured by ORAC method presented a positive and significant correlation (r = 0.851) (p <0.05) with monomeric anthocyanins content. Evaluation of antioxidant capacity by both methods were positively and significantly correlated (p <0.05) (r = 0.847).

MEMBROS DA BANCA:
Externo ao Programa - 628.646.967-20 - LOURDES MARIA CORRÊA CABRAL - EMBRAPA
Externo ao Programa - 507.802.047-00 - RONOEL LUIZ DE OLIVEIRA GODOY - EMBRAPA
Externo à Instituição - SUELY PEREIRA FREITAS - UFRJ