RESUMO
ABSTRACT: This research assessed the phenolic composition of Jussara pulp from the Brazilian states of Minas Gerais (MG) and Espírito Santo (ES) using HPLC-DAD-MS/MS. Seventeen anthocyanins were detected in fruits, derived from cyanidin, pelargonidin and peonidin. Among the non-anthocyanic phenolic compounds, flavonols (kaempferol, quercetin and isorhamnetin derivatives), flavan-3-ols (catechin, epicatechin, B-type procyanidins and unknown dimers) and resveratrol in its glycosylated form have been identified. Catechin (32.41-60.56 mg 100g-1) and epicatechin (18.86-40.92 mg 100g-1) were the main flavan-3-ols present in the fruits. The samples showed small concentrations of resveratrol glycosides (0.02-0.91 mg 100g-1). The analytical methodology used (HPLC-DAD-ESI-MS/MS) permitted the identification of newly reported compounds in this fruit.
RESUMO: O objetivo desta pesquisa foi avaliar a composição fenólica da polpa de Jussara dos Estados brasileiros de Minas Gerais (MG) e Espírito Santo (ES) usando HPLC-DAD-MS / MS. Dezessete antocianinas foram detectadas, dentre elas, derivadas de cianidina, pelargonidina e peonidina. Dentre os compostos fenólicos não antociânicos, foram identificados flavonóis (derivados de caempferol, quercetina e isorhamnetina), flavan-3-ols (catequina, epicatequina, procianidinas do tipo B e dímeros desconhecidos) e resveratrol em sua forma glicosilada. Catequina (32,41-60,56 mg 100g-1) e epicatequina (18,86-40,92 mg 100g-1) foram os principais flavan-3-óis presentes nas frutas. As amostras apresentaram pequenas concentrações de glicosídeos resveratrol (0,02-0,91 mg 100g-1). A metodologia analítica utilizada (HPLC-DAD-ESI-MS / MS) permitiu a identificação de novos compostos relatados presentes na composição da polpa de Jussara.
RESUMO
Two cultivars of sorghum were germinated at 25 or 30 °C for 1, 2, or 3 days to investigate the evolution of γ-Aminobutyric acid (GABA), total free phenolic compounds (FPC), hydroxycinnamic acid derivatives, free amino acid (FAA) profile, and antioxidant activity during malting. Results showed time-temperature interaction had significant influence on GABA accumulation, increasing over time at 25 °C, but keeping constant after first day at 30 °C. Free amino acid profile changed during malting with time and temperature, increasing until the third or second day at 25 and 30 °C, respectively. Content of hydroxycinnamic acid derivatives depended on time, temperature, and cultivar; ferulic was the phenolic acid found in greater amount. Pearson correlation analysis suggested malting generated not only FPC responsible for antioxidant activity, but also other bioactive compounds like FAA, particularly sulfur-containing ones. Germination for 3 days at 25 °C was the most suitable condition to obtaining functional sorghum malt.
RESUMO
Yerba mate is a beverage rich in bioactive compounds popular in South America. Polyphenols and methylxanthines were qualitatively and quantitatively analyzed in four commercial brands of yerba mate, as well as the antioxidant capacity of the beverages. Using LC/MSn analysis, 58 polyphenols were observed of which 4-sinapoylquinic acid, di- and tri-methoxycinnamoylquinic acids, two isomers of trimethoxycinnamoylshikimic acid and four isomers of caffeoyl-2,7-anhydro-3-deoxy-2-octulopyranosonic acid were identified for the first time in mate. Additionally, 46 polyphenols and 2 methylxanthines were quantified by HPLC-DAD. Hydroxycinnamic acid derivatives and flavonols comprised 90% and 10% of mate phenols, respectively, 3-caffeoylquinic (26.8-28.8%), 5-caffeoylquinic (21.1-22.4%), 4-caffeoylquinic (12.6-14.2%) and 3,5-dicaffeoylquinic acids (9.5-11.3%) along with rutin (7.1-7.8%) were the most abundant polyphenols, whereas caffeine was the main methylxanthine (90%). Ilex paraguariensis is an important source of polyphenols with moderate methylxanthines content; therefore its high antioxidant capacity was mainly associated to its polyphenolic composition.
Assuntos
Ácidos Cumáricos/química , Flavonóis/química , Ilex paraguariensis , Extratos Vegetais , Polifenóis , América do Sul , XantinasRESUMO
Este artigo descreve o desenvolvimento e a validação de método espectrofotométrico UV-Visível para quantificação de derivados do ácido o-hidroxicinâmico em folhas de Echinodorus grandiflorus. O método demonstrou ser linear (r² = 0,9974), preciso (DPR < 15%) na análise de matriz complexa e exata (recuperação = 107,56%).
This paper describes the development and the validation of an UV-Vis spectrophotometric method for the quantification of derivatives of o-hydroxycinnamic acid in leaves of Echinodorus grandiflorus. The method showed to be linear (r² = 0.9974), precise (RSD < 15%) in the analysis of complex matrix and accurate (recovery = 107.56%).