The effect of pretreatment on the fermentation of honeybush tea (Cyclopia maculata)

Abstract

Different pretreatments (bruising, hot and cold water) were used to study their effect on fermentation as measured by the quality parameters of honeybush tea (Cyclopia maculata). Bruising and pretreatment with water (hot and cold) were investigated as means to increase the fermentation rate and to improve product quality. The development of the desired dark-brown colour and honey-like flavour during fermentation was faster in hot and cold water treated material and gave a more uniform coloured product than with the bruising pretreatment. Liquor characteristics also improved with water pretreatment. A red–brown extract, compared with the light yellow–brown of untreated samples, was obtained with the water pretreatment. Hot water pretreatment inactivated the enzymes polyphenol oxidase (PPO) and peroxidase (POD), but did not terminate or impair fermentation. The inactivation of the enzymes, together with high temperature (>60°C) fermentation, indicated a chemical oxidation process rather than an enzymatic reaction in honeybush tea fermentation. © 1998 SCI.