Method for preventing discoloration of polyphenol

Abstract

Abstract PURPOSE:To prevent coloring and discoloring and stabilize the titled compound having astringent, skin conditioning action, etc., without inhibition of characteristics thereof, by the coexistence of a specific porphyrin-zinc complex and an organic reducing agent in a system containing polyphenol dissolved therein. CONSTITUTION:A porphyrin metallic complex having zinc as a coordinating metal and an organic reducing agent are blended with a system containing at least one of polyphenols, having >=3 phenolic hydroxyl groups in the molecule and dissolved in water or water-methanol mixture [at 99:1-1:99 mixing ratio (weight ratio) of water to ethanol] or an oil substance (e.g. vegetable oil or higher aliphatic hydrocarbons). The amount of the porphyrinzinc complex used is preferably normally 0.001-0.1wt.% based on the total amount of the composition and 0.001-100wt.% based on the weight of the polyphenol. The amount of the organic reducing agent used is preferably 0.01-10wt.% based on the weight of the composition and 1/20-100 times based on the weight of the polyphenol.

Inventors

• 👤 Mitsuo Kondo

Bibliographic Details