Changes in Headspace Volatiles during Manufacture of Concentrated Crape Juice

Abstract

Headspace volatiles of five samples during manufacture of the concentrated grape juice (Vitis labrusca L. var. concord) such as raw materials, heating process to extract color, clarification process with enzyme, concentration process and final products have been analyzed by Tenax GC trapping technique and capillary gas chromatography. Nineteen components, including eleven esters, five alcohols, two ketones and dimethyl sulfide, were identified. The loss of headspace volatiles during manufacture was most in heating process to extract color (53.3%), followed by concentrating process (27.3%) and clarifying process (18.1%).