Abstract: The invention provides a process of treating Rooibos plant material to obtain Rooibos tea extracts with improved extract yield and colour development. The process includes contacting Rooibos plant material with an effective amount of at least one exogenous enzyme under predetermined conditions thereby to obtain Rooibos tea extracts having improved extract yield and colour development. The enzyme is selected from pectinase, ferulic acid esterase, ?-glucanase, cellobiohydrolase, ?-xylanase and phenol oxidase and the Rooibos plant material is selected from green tea, fermented tea or spent tea.

Abstract: The invention discloses a method for producing a single cell oil containing gamma-linolenic acid characterized in that at least one microorganism of the order Mucorales preferably of the genus Mortierella, Actinomucor, Mucor, Rhizomucor or Rhizopus is cultured in a growth medium which is substantially starch and sugar free and which contains, as a carbon source material, at least one monocarboxylic acid of 2 to 5 carbon atoms, preferably acetic acid and recovering the oil from the resultant cultured microorganism biomass. The invention also relates to a method of treating the organic acid stream of the Fischer-Tropsch synthesis process to remove organic material therefrom.