title: Commercial peanut (Arachis hypogaea L.) cultivars in the United States: phytosterol composition.
abstract: Phytosterols in commercially grown Runner, Virginia, and Spanish peanuts (n = 221) from 2005 and 2006 were quantified by a combination of acid hydrolysis and alkaline saponification steps followed by gas chromatography-flame ionization detection and gas chromatography-mass spectrometry analysis of the trimethylsilyl derivatives. Δ(5)-Avenasterol, which partially degrades during acid hydrolysis, was quantified after alkaline saponification plus direct analysis of the steryl glucosides isolated by solid-phase extraction. β-Sitosterol, Δ(5)-avenasterol, campesterol, and stigmasterol were identified in peanut lipid extracts as the dominant sterols by retention time mapping and mass spectra with recoveries ∼99%. Clerosterol, Δ(5,24(25))-stigmastadienol, Δ(7)-sitosterol + cycloartenol, and one unidentified sterol were also present but at low levels. Free and esterified phytosterols accounted for ∼80% of the total sterols determined; the remainder was attributed to steryl glucosides. The total sterol level in Spanish market type peanuts (144.1 ± 5.3 mg/100 g) was significantly greater than both Runners (127.5 ± 6.3 mg/100 g) and Virginias (129.3 ± 6.9 mg/100 g) (P < 0.05). Tamspan 90 (146.9 mg/100 g) followed by OLIN (138.5 mg/100 g) showed the highest total sterol content among the cultivars examined. Cultivar effects were strongly significant (P < 0.001) for all phytosterols, whereas production year effects were strongly significant (P < 0.001) for Δ(5)-avenasterol, Δ(5,24(25))-stigmastadienol, and the combined quantities of Δ(7)-sitosterol + cycloartenol, which coeluted. Cultivar × year interactions were strongly significant (P < 0.001) in all sterols except for Δ(7)-sitosterol + cycloartenol (P < 0.01). Total phytosterol contents were markedly higher than those reported in the existing literature for Runner and Virginia type peanuts, partially attributed to the inclusion of steryl glucosides in the analysis.
authors.affiliation: Department of Food Science & Technology, The University of Georgia, 100 Cedar Street, Athens, Georgia 30602-7610, USA.
authors.forename: Eui-Cheol
authors.initials: EC
authors.lastname: Shin
authors.forename: Ronald B
authors.initials: RB
authors.lastname: Pegg
authors.forename: R Dixon
authors.initials: RD
authors.lastname: Phillips
authors.forename: Ronald R
authors.initials: RR
authors.lastname: Eitenmiller
mesh_terms: D010367:Arachis / Q000737:chemistry*; D045744:Cell Line, Tumor; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D010840:Phytosterols / Q000032:analysis*; D014481:United States
chemical_list: D010840:Phytosterols