GB776565A - Tea extract and process for producing the said extract - Google Patents

Abstract

Green tea leaves are disintegrated or perforated, the soluble constituents are separated and the liquid is evaporated to produce a liquid or dry extract, the soluble constituents being subjected, after disintegration or perforation to fermentation. The moisture content of the harvested leaf is reduced by evaporation, e.g., by barrelling or forced air circulation, and the leaf is then disintegrated or perforated so that the leaf structure is ruptured, e.g. in squeeze rolls, a hammer mill, a pulverizer a shedding machine or by shot blasting. The leaf is then exposed to air or oxygen and allowed to ferment with or without the assistance of barrelling or the like. When fermentation has proceeded for a sufficient time, it is arrested by heating the leaf matter by drying under vacuum or by at once leaching out the soluble constituents with hot water, steam or the like. If the leaf matter is dried, it can be leached out later on. The extraction of the soluble materials may be achieved by pressing or squeezing the leaf with or without first washing it. Alternatively the extracted liquor may be fermented and evaporated simultaneously and final evaporation after the arresting of fermentation may be carried out in a spray drier or by means of a vacuum evaporator and a band drier. The vapour given off may include some desirable esters and these may be separated from the vapour and returned to the extract. Milk, sugar or lemon may be added either to the extracted liquor or to the final product.