Propriedades físicas, químicas e biotividade de pseudofrutos de Hovenia dulcis Thunb.

Abstract

Resumo: Originaria da Asia Hovenia dulcis Thunb. (Rhamnaceae), conhecida como uva japonesa e encontrada tambem na America Central e do Sul, sul da Europa e norte da Africa. O fruto e uma capsula pequena anexada a haste (pedunculo) que quando amadurece, e a parte comestivel. O objetivo deste estudo foi caracterizar o conteudo nutricional, capacidade antioxidante, atividade antitumoral e comportamento reologico da polpa do pseudofruto e do mel, oriundo da florada de H. dulcis. Foram coletadas amostras de H. dulcis durante cinco meses, desde a fase imatura para senescente (I, II, III, IV e V), na cidade de Curitiba-PR. Trabalhou-se com cinco amostras de mel provenientes de quatro Estados brasileiros (SP, PR, SC, RS). Observou-se quanto a composicao nutricional que o pedunculo pode ser considerado uma interessante fonte de fibra dietetica (fracao soluvel), de acordo com regulamentos, brasileiro e europeu. No perfil de acidos graxos monoinsaturados, o pedunculo mais verde apresentou o valor mais elevado (6,95%), enquanto que o conteudo total de acidos graxos poliinsaturados foi mais elevado no pedunculo maduro (51,70%). Os pseudofrutos imaturos de H. dulcis sao fontes de compostos fenolicos, melhores do que os maduros sendo a melhor opcao para o aproveitamento industrial deste, mostrando uma capacidade mais elevada antioxidantes, analisadas pelos ensaios de Folin-Ciocalteu, CUPRAC, FRAP e ABTS. Durante a maturacao, o perfil de acidos organicos nos pedunculos foi do acido tartarico, majoritario, seguido do acido citrico. O extrato do pseudofruto revelou efeito inibitorio sobre quatro linhas celulares tumorais MCF7 (carcinoma de mama), HeLa (carcinoma cervical), HCT15 (carcinoma do colon) e HepG2 (carcinoma hepatocelular) para os pedunculos na fase de desenvolvimento incial e, ausencia de citotoxicidade confirmada em celulas sadias de figado suino (ensaio suforrodamina B). Quanto ao comportamento reologico da polpa, as curvas de fluxo indicaram um comportamento nao-Newtoniano pseudoplastico, comprovado pelo ajuste dos modelos (Ostwald-de-Waelle e Herschel- Bulkley) aos dados obtidos para a polpa dos pseudofrutos totalmente maduros. Para as amostras de cinco meis analisadas o estudo reologico demonstrou que em quase sua totalidade, estas apresentaram comportamento pseudoplastico, conforme aumentava a temperatura. A analise melissopalinologica constatou que duas amostras dos meis nao apresentaram predominancia da florada de H. dulcis Thunb. (. 45% de polen caracteristico). Pedunculos maduros sao uma boa alternativa para melhorar a qualidade nutricional das dietas modernas alternativas que buscam a diversificacao do ponto de vista sensorial e nutricional e nao convencional. Palavras-chave: pedunculos, comportamento reologico, atividade antitumoral, melissopalinologia, mel

Abstract: Originally from Asia Hovenia dulcis Thunb. (Rhamnaceae), known as Japanese grape is also found in Central and South America, southern Europe and North Africa. The fruit is a small capsule attached to the stem, also known as peduncle, once mature, it becomes de edible part of the fruit.The aim of this study was to distinguish the nutritional content, antioxidant capacity and antitumor activity of the fruit extract, as well as, the rheological behavior of the pulp and honey, from the flowering of H. dulcis Thunb. Samples were collected from H. dulcis Thunb. for five months, from the immature stage to the senescent (I, II, III, IV and V), in the city of Curitiba-Parana, Brazil. We worked with five honey samples from four Brazilian States (SP, PR, SC and RS).It has been observed that the nutritional composition of the peduncle can be considered an interesting source of dietary fiber, mainly the soluble fraction, according to Brazilian and European regulations. While investigating the profile of monounsaturated fatty acids, the greener peduncle presented the highest value (6.95%), while the total content of polyunsaturated fatty acids was highest in mature peduncles (51.70%).The immature pseudofruits of H. dulcis Thunb. are sources of phenolic compounds, they have proven to be a better source than the mature pseudofruits, as seen during the antioxidant capacity analysis by the Folin-Ciocalteu, CUPRAC, FRAP and ABTS assay, as such being a good option for industrial application. The profile of organic acids in peduncles was mostly of tartaric and citric acids. The pseudofruit extract revealed inhibitory effects on tumor cell lines four MCF7 (breast adenocarcinoma), HeLa (cervical carcinoma), HCT15 (colon carcinoma) and HepG2 (hepatocellular carcinoma) in the initial stage of peduncle development, and absence of cytotoxicity in healthy swine liver cells were confirmed (Sulforhodamine B assay). The rheological behavior of the pulp indicated a non-Newtonian pseudoplastic fluid, evidenced by the adjustment of models (Ostwald-de-Waelle and Herschel-Bulkley) and the data obtained through the pulp of the fully mature pseudofruits. During an increase in temperature was observed that the five honey samples analyzed displayed for the duration of the rheological study, in almost its entirety, pseudoplastic behaviour.Melissopalynology analysis found that two samples of honey did not show a predominance of flowering of H. dulcis Thunb. (. 45% of ragweed pollen characteristics).Ripe peduncles are a good alternative to improve the nutritional value of modern and unconventional diets, as alternatives that seek diversification of sensory and nutritional points of view. Keywords: peduncles, rheological behavior, antitumoral activity, melissopalynology, honey