Gas Chromatographic Investigations of the Volatile Constituents of Fruit Aromas

Pear Fruit Volatiles

“…Direct solvent extraction has been widely used to isolate fruit volatiles of various pear cultivars (Gasca 1969;Creveling and Jennings 1970;Strandjev 1974a,b;Quamme and Marriage 1977;Quamme 1984;Berger et al 1985a;Chen et al 1993;Avelar et al 1994;Beuerle and Schwab 1997a;Rizzolo 1998;Zoffoli et al 1998;Cigic and Zupancic-Kralj 1999;Lo Scalzo et al 2002). It has proven to be an effective extraction method yielding a large number of analytes, including highly water-soluble flavor constituents, which are typically poorly recovered by distillation and headspace analysis (Takeoka and Full 1997).…”

“…The most frequently used distillation method for isolating pear volatiles has been steam distillation (Harley and Fisher, 1927;Leonard et al 1954;Luh et al 1955;Claypool et al 1958;Spanyar et al 1964Spanyar et al , 1965Paillard et al 1970;Imayoshi et al 1995). Vacuum distillation method has been applied in several studies of pear volatiles, to minimize artifact formation by thermal degradation or hydrolysis, but is semiquantitative at best (Gasca et al 1969;Giintert et al 1998). As an alternative, simultaneous distillation-extraction (SDE) in a specialized apparatus such as the Licken/Nickerson (L/N) system has been used to produce the organic concentrates from pear fruits (Russell et al 1981;Quamme 1984;Shiota 1990;Horvat et al 1992;Takeoka et al 1992;Giintert et al 1998). The contents of the traps are combined and solvent extracted.…”

“…Further studies identified (sometimes tentatively) a few of the major volatile compounds of 'Bartlett' pear by using repetitive gas chromatography, infrared, ultraviolet and mass spectroscopy, nuclear magnetic resonance, and melting points (Jennings and Sevenants 1964;Creveling and Jennings 1970). The use of simple procedures such as acidic or alkaline extraction, hydrolysis, formation of intensely coloured derivatives, hydrogenation, or ozonolysis, as separation techniques prior to gas chromatographic analysis provided additional information on the chemical classes involved (Luh et al 1955;Jennings 1961;Giannone and Baldrati 1967;Gasca et al 1969;Creveling and Jennings 1970). The use of simple procedures such as acidic or alkaline extraction, hydrolysis, formation of intensely coloured derivatives, hydrogenation, or ozonolysis, as separation techniques prior to gas chromatographic analysis provided additional information on the chemical classes involved (Luh et al 1955;Jennings 1961;Giannone and Baldrati 1967;Gasca et al 1969;Creveling and Jennings 1970).…”