Identificação e quantificação de compostos fenólicos por CLAEDAD em polpa de frutas de cajá-umbu (Spondias spp.) e graviola (Annona muricata L.)

• Ano de defesa: 2013
• Autor(a) principal: Gualberto, Nayjara Carvalho
• Orientador(a): Narain, Narendra
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Programa de Pós-Graduação: Pós-Graduação em Ciência e Tecnologia de Alimentos
• Palavras-chave em Português: Frutas congeladas; Aspectos nutricionais; Ácidos fenólicos; Flavonóides; Cajá-umbu; Graviola; Antioxidantes; Spondias spp.; Annona muricata L.; CLAE-DAD; DPPH; ABTS; Fenólicos totais; Flavonóides totais; Metodologia; Validação.Spondias spp.; HPLC-DAD; Phenolic acids; Flavonoids; Phenolics; Methodology; Validation
• Área do conhecimento CNPq: CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS
• Link de acesso: http://ri.ufs.br/jspui/handle/riufs/16084

The increased consumption of tropical fruits in the diet is due to the high nutritional value, therapeutic effects and the presence of several compounds, including phenolic acids and flavonoids. These compounds are considered the most common phenolic antioxidants present in natural sources, as well as proven anti-inflammatory, antiallergic action, antitumour activity, antihepatotóxica, antiulcer, antiviral, antiplatelet activity and antimicrobial actions. In this context, the aim of this study was to identify and quantify the phenolic compounds present in frozen pulp of cajá-umbu (Spondias spp.) and soursop (Annona muricata L.) by HPLC-DAD, evaluating the antioxidant capacity of these compounds against ABTS and DPPH. In addition to these analyses, further physico-chemical characterization of pulps was carried out for pH, titratable acidity, soluble solids, ash, lipid, protein and moisture contents. For the identification of phenolic compounds by HPLC-DAD, two methods were proposed: Method 1 using the the mobile phase of acetonitrile and 1% formic acid and Method 2 using water as the mobile phase acidified with TFA and acetonitrile acidified with TFA. Solid phase extraction with C18 cartridge was performed in both methods using elution with different solvents or combinations such as acetone, methanol and ethyl acetate. We performed a processing of the two analytical methods proposed in order to obtain a satisfactory separation of the peaks in the samples. Only after injection and analysis of 13 analytical standards of phenolic acids and flavonoids in the two methods and refined by performing calculations of chromatographic parameters (Rs, k, α), it was established that the improvement in the method that was first obtained an adequate separation of analytical standards, with a Rs> 1.5.This method was then validated according to the guidelines established by INMETRO, following the parameters of selectivity, linearity and concentration range, limit of detection and quantification, as well as testing precision (repeatability) and recovery. In the fraction of acetone/methanol of soursop pulp, larger amount of phenolic compounds analyzed by HPLC-DAD, including gallic 12 acid, chlorogenic acid, catechin and a compound with a spectrum similar to ρ-coumaric acid were identified. The fraction of acetone/ethyl acetate extracted more total phenolics and flavonoids from the pulps of two fruits tested. In the analysis of antioxidant capacity by ABTS method, the fractions extracted with acetone/methanol were more efficient at capturing the radical in both the fruits. But in the analysis by DPPH method, only soursop pulp showed the antioxidant activity. The results show that the soursop pulp is more effective in capturing radicals due to its high content of bioactive compounds than that of caja- umbu pulp.