THE MACRONUTRIENT CONTENT OF FRACTIONS FROM JERUSALEM-ARTICHOKE TUBERS (HELIANTHUS-TUBEROSUS)

Three cultivars of Jerusalem artichoke were harvested in late fall, wa shed thoroughly, trimmed of any damaged tissue then blanched with stea m. The tubers were frozen, freeze dried then manually separated into s kins and skinless tubers which were extracted with hot water. Jerusale m artichoke tubers, on a dry basis, yielded approximately 76% soluble sugars (combined fractions from the drain liquor and hot water extract of skinless tubers and skins) and the remaining 24% as an insoluble r esidue. Analysis showed that, on a dry weight basis, the residues cont ained 20-25% protein which was double the concentration in the soluble extract; the residues also contained up to 43% total dietary fiber. S oluble sugars ranged over 75-85% of the dry matter in the hot water ex tracts, which was double the amount retained in the residue. The lowes t ash content (3.2-4.9%) was found in the skinless tubers residue and the highest (5.9-7.5) was in the skin residue.