title: trans-resveratrol content in commercial peanuts and peanut products.
abstract: A modified high-performance liquid chromatographic (HPLC) method for determination of trans-resveratrol (resveratrol) in peanuts and peanut products has been developed. Resveratrol was extracted with acetonitrile-water (90/10, v/v) by blending with diatomaceous earth at high speed followed by purification of an aliquot of the extract on a minicolumn packed with Al(2)O(3)-ODS (C(18)) mixture. The column was eluted with acetonitrile-water (90/10, v/v), eluate was evaporated under nitrogen, and residue was dissolved in HPLC mobile phase. Resveratrol in an aliquot of purified extract was quantitated by HPLC on silica gel with n-hexane-2-propanol-water-acetonitrile-acetic acid (1050/270/17/5/1, v/v) as a mobile phase. The recovery of resveratrol added to diatomaceous earth at 0.05 microg/g was 98.95 +/- 17.79%; the recovery of the standard added to fresh peanuts (with 0.070 microg/g natural level of resveratrol) at 0.50, 5.00, and 10.00 microg/g was 117.23 +/- 8.87, 100.10 +/- 2.49, and 100.45 +/- 1.51%, respectively. The quantitation limit of resveratrol in fresh peanuts was about 0. 01 microg/g. Roasted peanuts had the lowest content of resveratrol of 0.055 +/- 0.023 microg/g (n = 21), while in peanut butter its concentration was significantly higher, 0.324 +/- 0.129 microg/g (n = 46), and boiled peanuts had the highest level of 5.138 +/- 2.849 microg/g (n = 12). Resveratrol content in commercial peanut products was similar to the resveratrol content of the raw peanut fractions routinely used for making them.
authors.affiliation: National Peanut Research Laboratory, Agricultural Research Service, U.S. Department of Agriculture, Dawson, Georgia 31742, USA. vsobolev@nprl.usda.gov
authors.forename: V S
authors.initials: VS
authors.lastname: Sobolev
authors.forename: R J
authors.initials: RJ
authors.lastname: Cole
mesh_terms: D010367:Arachis / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D005511:Food Handling; D000077185:Resveratrol; D013267:Stilbenes / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D013267:Stilbenes; D000077185:Resveratrol