ABSTRACT
RESUMO Camellia sinensis é amplamente conhecida por seus efeitos benéficos à saúde humana. Dentre as diversas formas de processamento desta erva, o chá verde e chá preto são os mais populares. Neste trabalho objetivou-se avaliar os teores de fenólicos totais e flavonoides em amostras de 25 diferentes marcas disponíveis à venda em farmácias e supermercados de Salvador-Ba. Os resultados obtidos apresentaram diferenças significativas na concentração dos compostos fenólicos entre as marcas de chá verde estudadas. No estudo também ficou comprovado que, no preparo do chá verde, as amostras obtidas por infusão aquosa com agitação mecânica apresentaram maiores teores de polifenóis e flavonoides em relação àquelas que não foram submetidas à agitação.
ABSTRACT Camellia sinensis is widely known for its beneficial effects to human health. Among the various forms of processing this herb, the green and the black tea are the most popular ones. The objective of this work was to evaluate the contents of total polyphenol and flavonoids in samples of 25 different brands available for sale in pharmacies and supermarkets of Salvador-Ba. The results showed great variation in the concentration of phenolic compounds among the brands of green tea which were tested. In the study it was also proven that in the green tea preparation the samples obtained by mechanical agitation with aqueous infusion showed higher levels of phenolics and flavonoids contents than those which were not subjected to stirring.
Subject(s)
Flavonoids/analysis , Camellia sinensis/metabolism , Polyphenols/analysis , Antioxidants/pharmacologyABSTRACT
Tinturas preparadas com as folhas de Camellia sinensis (chá verde), foram caracterizadas visando a obtenção de extratos enriquecidos em polifenóis. As tinturas foram obtidas por meio de maceração estática da droga pulverizada, com diferentes misturas de 60, 70, 80 e 94,5% de etanol em água. Em seguida foram filtradas e, após 8 dias de extração, realizaram-se as analises: organoléptica, pH, densidade, determinação do resíduo seco, perfil cromatográfico por camada delgada, e teor de polifenóis. Os resultados demonstraram que o solvente (mistura hidroalcoólica a 60 ou 70%) extraiu a maior quantidade de constituintes químicos do chá verde; também foi o mais seletivo ao extrair, especificamente os polifenóis. Estes dados sugerem que a utilização de álcool etílico a 60 ou 70% conduz à obtenção de tinturas mais ricas em polifenóis, a partir das folhas do chá verde (C. sinensis).
In this work, we prepared and characterized Camellia sinensis leaf tinctures aiming to obtain a polyphenol-enriched extract. The tinctures were prepared through the static maceration process of the powdered drug, at different mixtures 60, 70, 80 and 94.5% of ethanol in water. The tinctures were filtered, and after 8 days of extraction, submitted to organoleptic analysis, determination of pH, density analysis, dry residue analysis, thin layer chromatographic profile and polyphenol percentage analysis. The results showed that the 60 or 70% alcohol-water mixture has the best extraction of the constituents of green tea and it was more selective to extract, specifically, the polyphenols of the plant. These data suggest the use of 60 or 70% ethanol to carry out polyphenol-enriched tinctures from green tea leaves (C. sinensis).
Subject(s)
Tea/classification , Mother Tincture , Camellia sinensis/metabolism , Plants, Medicinal/classification , Quality Control , Plant Extracts/administration & dosage , Polyphenols/analysisABSTRACT
Harpin proteins from plant pathogenic bacteria can stimulate hypersensitive cell death (HCD), drought tolerance, defence responses against pathogens and insects in plants, as well as enhance plant growth. Recently, we identified nine functional fragments of HpaG;Xooc, a harpin protein from Xanthomonas oryzae pv.oryzicola, the pathogen that causes bacterial leaf streak in rice. Fragments HpaG;1-94'HpaG;10-42, and HpaG;62-138, which contain the HpaG;Xooc regions of the amino acid sequence as indicated by the number spans, exceed the parent protein in promoting growth, pathogen defence and HCD in plants. Here we report improved productivity and biochemical properties of green tea (Camellia sinensis) in response to the fragments tested in comparison with HpaG;Xooc and an inactive protein control. Field tests suggested that the four proteins markedly increased the growth and yield of green tea, and increased the leaf content of tea catechols, a group of compounds that have relevance in the prevention and treatment of human diseases. In particular, HpaG;1-94 was more active than HpaG;Xooc in expediting the growth of juvenile buds and leaves used as green tea material and increased the catechol content of processed teas. When tea shrubs were treated with HpaH;Xooc and HpaG;1-94 compared with a control, green tea yields were over 55% and 39% greater, and leaf catechols were increased by more than 64% and 72%, respectively. The expression of three homologues of the expansin genes, which regulate plant cell growth, and the CsCHS gene encoding a tea chalcone synthase, which critically regulates the biosynthesis of catechols, were induced in germinal leaves of tea plants following treatment with HpaG;1-94 or HpaG;Xooc. Higher levels of gene expression were induced by the application of HpaG;1-94 than HpaG;Xooc. Our results suggest that the harpin protein, especially the functional fragment HpaG;1-94, can be used to effectively increase the yield and improve the biochemical properties of green tea, a drink with medicinal properties.
Subject(s)
Bacterial Proteins/chemistry , Camellia sinensis/metabolism , Humans , Molecular Sequence Data , Oryza/microbiology , Peptide Fragments/chemistry , Plant Diseases/microbiology , Tea/chemistry , Xanthomonas/pathogenicityABSTRACT
Tea plants (Camellia sinensis) contain 5-6% caffeine that is responsible for the stimulating effect of the beverage. As the tolerance to caffeine varies among individuals, low caffeine tea would be an ideal alternative. While assessing the potential of a few selected bacteria-Bacillus licheniformis, B. subtilis and B. firmus, to multiply on nutrient medium supplemented with glucose (5%) and tea leaf extract (2%), it was observed that only B. licheniformis could proliferate on this medium. Hence, B. licheniformis was used for further studies. Tea plants were sprayed with a suspension of B. licheniformis at a dilution of 5 x 10(8) CFU/ml containing 0.1% Tween 80 as surfactant. In situ lowering of caffeine from tea leaves was evident without affecting the quality of the other tea components. Further, there was no change in the morphological and physiological characteristics as well. It is suggested that spraying of B. licheniformis may be useful in yielding decaffeinated tea with good flavour and aroma.