Anthocyanins, other flavonoids and related polyphenolic compounds are extracted from fruits or highly pigmented garden vegetables and their by-products using subcritical water with or without a secondary cosolvent. This method has the advantages of being relatively inexpensive, minimizes or totally avoids the use of objectionable solvents, and provides a facile means for supplying an ample source of concentrated phytochemicals for use in food formulation, dietary supplements and phyto-pharmaceutical applications.