| dc.creator | Restrepo Aristizabal, María Fernanda | |
| dc.creator | Salinas Villada, Juan Felipe | |
| dc.date | 2016-06-03T21:40:07Z | |
| dc.date | 2021-11-03T16:18:53Z | |
| dc.date | 2016-06-03T21:40:07Z | |
| dc.date | 2021-11-03T16:18:53Z | |
| dc.date | 2016 | |
| dc.identifier | T547.64 H565;6310000114496 F5548 | |
| dc.identifier | https://hdl.handle.net/11059/6293 | |
| dc.description | Herbal medicines have long been used to treat chronic diseases such as cancer, neurodegeneration and diabetes, usually in the form of herbal teas, also called tisanes. Tea, second only to water, is the most highly consumed beverage worldwide and its medicinal and health properties, long known to early Chinese civilizations, have been widely explored. The consumption of green tea in Colombia is a recent trend and the market is continuously growing, then the most common commercially available types of green tea were tested in this study; Oriental, Lipton, Hindú and Jaibel. The main objective of this study was to determine and compare the amount of polyphe-nols present in tea samples considering extraction in water at room temperature and stirring every 30 seconds for 5 minutes. The antioxidant capacity was determined by the 1,1- diphenyl-2-picrylhydrazyl (DPPH) free-radical scav-enging assay and the oxygen radical absorbance capacity (ORAC) assay. Concentrations ranging from 22.36 ± 0.98 to 41.29 ± 0.86 mg Trolox equivalent / g dry sample for DPPH assay and 22.95 ± 1.31 to 46.25 ± 2.05 mg Trolox equiv-alent / g dry simple were determined for ORAC assay. It was also found that the amount of total phenols in tea samples ranging from 2.53 ± 0.25 to 14.63 ± 0.53 mg gallic acid equivalent (GAE) / g dry sample and total flavonoid content concentration was obtained from 2.67 ± 0.20 to 7.08 ± 0.38 mg catechin equivalent / g dry simple. The antioxidant activity and total flavonoid content were highly correlated for both DPPH (r2= 0.9911) as ORAC (r2 = 0.9968). Tea extracts from the Oriental brand had the highest polyphenol content showing greater biological ac-tivity, contrary to Jaibel tea brand which recorded the lowest concentrations in all analyzes. | |
| dc.format | application/pdf | |
| dc.format | application/pdf | |
| dc.language | spa | |
| dc.publisher | Pereira : Universidad Tecnológica de Pereira | |
| dc.publisher | Facultad de Tecnología | |
| dc.publisher | Química Industrial | |
| dc.rights | Attribution-NonCommercial-NoDerivatives 4.0 International | |
| dc.rights | EL AUTOR, manifiesta que la obra objeto de la presente autorización es original y la realizó sin violar o usurpar derechos de autor de terceros, por lo tanto la obra es de exclusiva autoría y tiene la titularidad sobre la misma. PARÁGRAFO: En caso de presentarse cualquier reclamación o acción por parte de un tercero en cuanto a los derechos de autor sobre la obra en cuestión, EL AUTOR, asumirá toda la responsabilidad, y saldrá en defensa de los derechos aquí autorizados; para todos los efectos la universidad actúa como un tercero de buena fe. EL AUTOR, autoriza a LA UNIVERSIDAD TECNOLOGICA DE PEREIRA, para que en los términos establecidos en la Ley 23 de 1982, Ley 44 de 1993, Decisión andina 351 de 1993, Decreto 460 de 1995 y demás normas generales sobre la materia, utilice y use la obra objeto de la presente autorización. | |
| dc.rights | http://creativecommons.org/licenses/by-nc-nd/4.0/ | |
| dc.subject | Extractos vegetales | |
| dc.subject | Análisis químico de las plantas | |
| dc.subject | Plantas medicinales | |
| dc.subject | Extracción (Química) | |
| dc.subject | Polifenoles | |
| dc.subject | Antioxidantes | |
| dc.title | Evaluation of the antioxidant capacity and content of polyphenols obtained from tea (Camellia sinensis) of four brands sold in Colombia by extraction at room temperature | |
| dc.type | bachelorThesis | |
| dc.type | acceptedVersion | |
