Antioxidants from plant materials in the technology of beer stabilization

Abstract

Through every stage of the brewing process, oxygen badly affects the taste and stability of the final beer. at the stage of boiling wort with hop oxygen performs two different functions. It is positive for isomerization process of α-acids, and it is negative for degradation processes in isoα-acids. as iso-α-acids are destructed analytical value of wort and beer bitterness reduces, and its nature deteriorates. Normal alcoholic fermentation happens in the absence of oxygen, and this is the cornerstone of the technological scheme of accelerated production of beer. Every researcher recognized the negative role that oxygen plays in maturation. oxidation can be stopped or slowed down by using antioxidants which either react with generated peroxide free radicals or destroy peroxides without free radicals being generated. To prevent oxidative degradation of iso-α-acids, accumulation dynamics has been studied with regard to trends of accumulation of bitter substances in the hopped wort depending on the time when antioxidants from the bark of oak and peppermint leaves are added into boiling wort and hop mixture. Studies have shown that it is desirable to add antioxidants from the bark of oak and peppermint leaves in 50 minutes since after wort with hop is getting boiled, in order to prevent oxidative destruction of iso-α-acids. It is found that antioxidant phenolic compounds from oak bark and leaves of peppermint most effectively contribute to the coagulation of wort proteins.