Determination by HPLC of ascorbic acid and tocopherols in fruits

Abstract

The fruits and vegetables are recommended for human feeding due to the richness of antioxidant compounds. The bioactive compounds from the diet, such as vitamins C and E are important to reduce the speed of initiation or prevent the spread of free radicals. The objective of the work was to evaluate the ascorbic acid and tocopherol content of selections of Pitanga (Eugenia uniflora L.), butiá (Butiá capitata), blackberry (Rubus spp), blueberry (Vaccium Reade ashei), loquat (Eribrotia japônica), jambolan (Eugenia jambolana), purple araçá (Psidium rufum), physalis (Physalis peruviana), pear (Pyrus communis) and peaches (Prunus persica). The fruits were from 2006/2007/2008 harvest, which were obtained in Pelotas (RS) region. The tocopherol analyses were performed according Rodrigues-Amaya (1999), and ascorbic acid according Vinci, Botre e Ruggieri (1995). The tocopherol and ascorbic acid identification and quantification was performed by high-efficiency liquid chromatography system (HPLC), using a fluorescent detector for tocopherol (excitation of 290 nm and emission of 330 nm) and a UV-Visible (254 nm) for ascorbic acid. The blackberry cv. Tupy showed the highest tocopherols content (8,251 ?g.g^-1 fruit) when compared with the other fruit content. The tocopherol was not found in pears and peaches of cv. Sensação and cv. Granada. The ascorbic acid content ranged from 9,291 mg.g^-1 fruit for the physalis to 0,013 mg.g^-1 fruit for the jambolan. It was concluded that the fruits are good sources of bioactive compounds.