Vol. 123 (2010): Proceedings of the Florida State Horticultural Society
Citrus

A Comparison of Common and Different Volatiles in “White” Guava and ‘Valencia’ Orange Leaves

Photos: Florida contains over half the wild orchid species found in the United States, at roughly 100 species. The endangered Ghost Orchid (Dendrophylax lindenii) makes its home in the area of southern Florida known as the Big Cypress Swamp (including the

Published 2010-12-01

Keywords

  • static headspace,
  • SPME,
  • GC-MS

Abstract

Static head-space volatile extraction was conducted to concentrate ‘Valencia’ orange and guava leaf volatiles, which were subsequently analyzed using gas chromatography–mass spectrometry (GC-MS). Forty-seven volatiles were identified in both guava and ‘Valencia’ leaves. There were 35 volatiles unique to each leaf type and 12 volatiles in common. Guava leaf volatiles consisted primarily of esters whereas ‘Valencia’ leaf volatiles consisted almost exclusively of terpenes. For guava, there were 20 esters, 13 terpenes/sesquiterpenes, 7 aldehydes, 2, ketones, 2 alcohols, 2 furans, and one acid. ‘Valencia’ leaf volatiles consisted of 33 terpenes/sesquiterpenes, 7 alcohols, 4 aldehydes, and 3 esters. Of the 12 volatiles in common, 8 were terpenes, 3 were aldehydes, and one alcohol. Identification was based on matching sample MS fragmentation patterns with those in the NIST library as well as matching literature standardized retention index values. Identifications were confirmed by matching observed fragmentation patterns and retention values with those of known standards run under identical conditions. The volatile profiles from guava and ‘Valencia’ orange leaves were profoundly different.