The Flavor Spectrum of Apple‐Wine Volatiles^a

Abstract

SUMMARY Sixteen compounds in the volatile fraction of apple wine were isolated and identified. Ethyl chloride was preferred over pentane or iso‐pentane in extraction of the volatiles because it gave higher yields and its lower boiling point allowed almost solvent‐free extracts in a very short time. Gas‐liquid chromatography was used in separation and purification of the volatiles. The compounds were identified by comparing retention times, infrared spectra, and melting point of derivatives with those of known compounds.

The Flavor Spectrum of Apple Wine Volatiles.

“…Examination of the volatile-acid fraction in apple wine strippings revealed that there are 10 distinct peaks in the chromatograms when separated by Ucon 50-HB-2000 on firebrick C-22 and Ucon-nonpolar on Chromosorb W. In previous work (Matthews et al, 1962) the components of the neutral fractions were isolated individually and identified by their retention times and at least one or more of three techniques, i.e., infrared spectrum, paper partition chromatography, or derivative formation.…”

“…The volatile acidic fraction was recovered from the alkaline aqueous solution by adjusting the pH to 1.0 with 18N H&O, and then distilling with steam. The condensate was saturated with NaCl, and the acids were extracted by the procedure described by Matthews et al (1962), in which 150 ml of the aqueous solution of volatile acid was extracted with 15 ml of ethyl chloride at 0°C for 30 min on a mechanical shaker.…”

“…The chief concern in this laboratory has been to define and differentiate fiavors and off-flavors in apple wine. In previous work (Matthews et al, 1962) we reported the isolation and identification of 1s compounds present in the volatile fraction of apple wine, but did not detect an acidic fraction when a column packing consisting of Carbowax-400 on firebrick C-22 was used. Subsequent to that investigation of the volatile ethyl-chloride-extractable components of apple wine, the possibility of the presence of volatile free acids was brought to our attention.…”