Process for producing polyphenol extract concentrate using sweet potato stems and leaves

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a concentrated liquid of polyphenol extract, enabling efficient purification of polyphenol extract using sweet potato foliage as a raw material.SOLUTION: A method for producing a concentrated liquid of polyphenol extract comprises: a foliage washing step of washing sweet potato foliage; a polyphenol extraction step of extracting polyphenol from the sweet potato foliage after the foliage washing step; an extract preservation step of repeating a foliage washing step and a polyphenol extraction step until the extract reaches a given amount and preserving polyphenol extract temporarily; a polyphenol extract purification step of purifying the given amount of the polyphenol extract after a completion of the extract preservation step; and a concentration step of concentrating the polyphenol extract after purification.