Some Volatile Components of Vitis Vinifera Variety White Riesling.

SUMMARY— Volatile components of the grape Vitis vinifera var. White Riesling were isolated by reduced pressure steam distillation followed by solvent extraction and fractionation by gas-liquid chromatography. Individual components were identified by a combination of the techniques of functional group analysis, gas-chromatographic relative retention times, and infrared spectroscopy. Major components are: ethanol, isobutanol, 2.methylbutanol, 3-methylbutanol, 2-hexenal, n-hexanol, trans-2-hexen-1-01, and 2.Dhenethanol. Alcohols oresent in relatively smaller amounts are: methanol, n-butanol, n-pen-tanol, n-heptanol, linaloöl, n-octanol, n-decanol, and benzyl alcohol. Acids constitute only a small part of the total volatiles of White Riesling, the maior acids being: acetic, n-caproic, 2-hexenoic, n-caprylic, n-pelargonic, and n-capric. Acids present in trace amounts are: propionic, isobutyric, n-butyric, 2-methylbutyric, isovaleric, isocaproic, n-heptanoic, n-undecanoic, succinic, and ethyl acid succinate. The only esters detected were trace quantities of ethyl acetate and isoamyl acetate.