ULTRASTRUCTURAL CHANGES IN TEA LEAVES DURING ORTHODOX BLACK TEA MANUFACTURE

Changes in fine structure of upper epidermal and palisade cells of fresh, withered, rolled, fermented and fired tea leaves were studied. In the fresh immature leaves, the polyphenols are located mainly in the vacuoles of the first 2-3 layers of upper palisade cells. Loss of water during withering causes slight disorganization in the fine structure of the organelles. Rolling causes extensive disorganization of the organelles, membranes and cell walls. The chloroplast membranes, which are rich in lipoproteins, rupture and parts of it vesiculate. These controlled and defined changes in fine structure leading to cell death, characterized by cleavage of cell walls in certain areas, rupture of the membranes, organelles and their inclusions, followed by cramped plasmolysis of cellular contents, throw more light on the biochemical changes that take place during tea manufacture.