A process for extracting phytochemicals from plants. The process generally comprises controllably slurrying a selected plant material in a volume of water, adding a selected enzyme the the slurry while it is controllably agitated, then heating the controllably agitated slurry-enzyme mixture to a temperature from the range of 400 °C to 1100 °C, and then maintaining the slurry-enzyme mixture at that temperature for a selected period of time. The slurry is then separated into a solids fraction and a liquids fraction that contains extracted phytochemicals.. The liquids fraction is controllably de-watered to produce a fluid extract concentrate. The liquids fraction may optionally be dried to produce a dried extract concentrate. Suitable enzymes for use with this process include .alpha.-amylases, .beta.-amylases, endo-.beta.-1,4-glucanases, cellobiohydrolases, cellulases, hemicellulases, .beta.-glucosidases, .beta.-xylosidases, xylanases, pullulases, esterases and mixtures thereof.
