Banca de QUALIFICAÇÃO: MONIQUE BARRETO SANTOS

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : MONIQUE BARRETO SANTOS
DATA : 06/12/2018
HORA: 09:00
LOCAL: DTA/IT
TÍTULO:

Physicochemical, thermal and rheological properties of carboxymethyl tara gum (Caesalpinia spinosa)

 

PALAVRAS-CHAVES:

Carboxymethylation, Rheological properties, Galactomannan, Seed gum

PÁGINAS: 31
GRANDE ÁREA: Ciências Agrárias
ÁREA: Ciência e Tecnologia de Alimentos
SUBÁREA: Ciência de Alimentos
ESPECIALIDADE: Química, Física, Fisico-Química e Bioquímica dos Alim. e das Mat-Primas Alimentares
RESUMO:

Carboxymethyl tara gum (CMTG) was synthesized from the reaction between tara gum (TG) and monochloroacetic acid (MCA) in the presence of sodium hydroxide (NaOH). The modification reaction was optimized in terms of MCA/NaOH ratio, reaction time and temperature thus evaluated for degree of substitution (DS). The etherification was confirmed by FTIR and ¹³C NMR and characterized by different analyzes. After carboxymethylation, CMTG showed new bonds at 1592, 1413 and 1320 cm^-1 by FTIR and a new peak at δ = 178 ppm by ¹³C NMR concerning the insertion of the carbonyl group. SEM showed higher degradation on the surface of the CMTG particles and XRD indicated low crystallinity of the CMTG. Thermal analysis (TGA and DSC) revealed a lower thermal stability of carboxymethylated gum compared to unmodified gum. Despite the insertion of negative charges demonstrated by the potential-zeta, according to the rheological analyzes CMTG and TG presented pseudoplastic behavior, having CMTG presented lower viscosity at the concentrations studied.

MEMBROS DA BANCA:
Presidente - 014.548.996-54 - EDWIN ELARD GARCIA ROJAS - UFF
Interno - 2311373 - MARIANA TEIXEIRA DA COSTA MACHADO
Externo à Instituição - SILVIO JOSÉ SABINO - UFF