15C-27 |
trans-Resveratrol content of grape berries cultivated in Korea |
D. J. KIM1, S. S. Lee, and J. Lee. (1) Department of Food Science and Technology, Chungbuk National Univeristy, Chongju, 361-763, South Korea Resveratrol(3,4¢,5-trihydroxystilbene) is a naturally occurring phytoalexin compounds produced by grape berries in response to stress such as fungal infection or UV irradiation and may be one of the compounds responsible for the health benefits of red wine. The presence of resveratrol has been extensively reported for wine and few studies have focused on grape berries. The objective of research was to develop a simple and accurate HPLC method for the quantitative determination of trans-resveratrol in grape berries. Grape berries were obtained from Okcheon Grape Experiment Station in Korea. Samples of finely ground grape berries (25g) were weighed in a 250mL beaker. The extracting solvent (50ml of methanol) was added to the sample and homogenized with a Polytron homogenizer for 3 min. The extract was centrifuged for 10 min at 10000 rpm and diluted to 100mL volumetric flask. This solution was injected into the HPLC analytical system. The resveratrol was separated isocratically an LiChrospher100RP-18 column, using a mobile phase containing acetonitrile:water(40:60, v/v) and detected by UV detector at 306nm. Assay value of resveratrol on 18 grapes berries cultivated in Korea ranged from 4.87 to 49.6ug/100g sample. Overall recovery of this study was over 90% (n=12). The linearity test for quantitation was carried out over the range of 0.0 to 18.5 mg/mL and showed an excellent linear relationship. The repeatability and reproducibility (% coefficient of variation) was less than 5%. Limit of detection was 0.36ng/injection(20ul). Generally, the results of validation parameters were reliable and satisfactory. We have described a simple and reliable method suitable for the analysis of resveratrol in grape berries and wine samples. The trans-resveratrol content in 18 grape berries cultivated in Korea was provided for nutritional information
Session 15C, Food Chemistry: Food composition and analysis
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