Banca de DEFESA: ENIO RAFAEL DE MEDEIROS SANTOS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ENIO RAFAEL DE MEDEIROS SANTOS
DATA : 18/09/2017
HORA: 09:00
LOCAL: SALA DO CATRE
TÍTULO:

"DEVELOPMENT OF EXTRATIVE PROCESSES FROM RUMEX ACETOSA AND CHEMICAL CHARACTERIZATION OF ITS EXTRACTS."

PALAVRAS-CHAVES:

Rumex acetose. Extraction by pressurized fluids. Trans-resveratrol. Emodina. Antioxidant activity. Total phenolic content.

PÁGINAS: 139
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Química
RESUMO:

 Researches presented in excess of free radicals as products of various diseases and cardiovascular diseases. In this context, the use of natural phenolic compounds by an item of excellent antioxidant activity and by inhibiting formation of radicals emerges. In the middle of the studies on the compounds, antioxidants: cis and trans-resveratrol, cis and trans-piceid and emodin gain prominence in the scientific environment. Scientific works prove the presence of phenolic compounds in the herbaceous "Azedinha" (Rumex acetosa), so its roots have been increasingly used in pharmacological applications. AEG, Microwave Extraction (MAE), solvent extraction (APE), microwave extraction (MAE), low pressure solvent extraction (LPSE). In SFE, it was evaluated the process variables, kinetics of extraction, yield and solubility of the extract. In the PLEs, both as evaluated, temperature and pressure, as an influence of the different solvents (water, ethanol, hexane, toluene, acetonitrile and isopropanol) and their use sequenced as sequenced PLE. The curves obtained in the SFEs and PLEs were adjusted according to the models: Martinez, Crank and Sovová and their calculated mean deviations. In the Soxhlet extraction the use of four solvents (ethanol, acetonitrile, isopropanol and butyl alcohol) was evaluated, whereas in LPSE and MAE extraction it was used as solvent. The use of supercritical anti-solvent (SAS) propagation as a form of drying has also been tested. The total phenolic content, the antioxidant capacity of the extracts and the main components of the μm extract determined. The yields obtained in all the techniques varied from 0.2 to 8.7%, being the best result obtained in the PLE extraction with ethanol. SUE presented the extract with the highest concentration of emodin (42.82 mg/g). The trans-resveratrol concentration in all extracts ranged from 1.03 to 5.57 mg/g, depending on the technique used. The antioxidant activity and the total phenolic compounds resulted in values between 3.48 and 163.43 μg/mL and 27.63 and 157.04 mgEAG/g_e, respectively, depending on the technique used. MAE obtained extracts with 130.67 mgEAG/g_e and 3.48 μg/mL in 30 minutes of operation. Extracts with pressurized fluids (PLEs and SFEs) showed excellent results, especially with respect to sequential extraction, where trans-resveratrol and emodine separation was possible, not with extraction of phenols of high and medium polarity, such as SFE.

MEMBROS DA BANCA:
Externo à Instituição - BENTO PEREIRA DA COSTA NETO - IFRN
Presidente - 348100 - ELISA MARIA BITTENCOURT DUTRA DE SOUSA
Externo à Instituição - ELISANGELA LOPES GALVAO - UFERSA
Interno - 1670497 - HUMBERTO NEVES MAIA DE OLIVEIRA
Externo à Instituição - MARCIONILA DE OLIVEIRA FERREIRA - IFRN
Externo à Instituição - RICARDO HENRIQUE ROCHA DE CARVALHO - UFERSA