茶饮料、速溶茶、茶浓缩汁的加工及贮藏过程中形成的茶汤沉淀，不仅影响产品的外观品质，同时也造成产品风味品质的下降。然而，由于沉淀形成过程比较复杂，至今缺乏明确的形成机理和调控方法，一直无法得到解决。目前，国内茶饮料企业主要采用物理去除或化学转溶的方法来去除或抑制沉淀的形成，这不仅会导致茶叶大量有效成分损失，功能保健价值降低，同时也会造成产品外观颜色和内在品质的明显劣变，严重阻碍了我国茶饮料行业的进一步发展。冷后浑，又叫茶乳酪，是指茶汤冷却后产生的浑浊现象，冷后浑是茶汤沉淀形成的前期过程。茶汤沉淀分为可逆沉淀和不可逆沉淀，其化学组成、形成机理及影响因素都存在明显不同。本文针对这一问题，对茶汤沉淀的化学组成、沉淀形成影响因素、沉淀形成机理、沉淀形成调控方法等方面进行综述，为有效调控茶饮料沉淀形成奠定研究基础。%Sediment easily forms during the process and storage of tea beverage, instant tea powder and concentrated tea, which not only has an unattractive appearance, but also detracts from the flavor quality of tea products. However, there are no clear forming mechanism and controlling methods of tea sediment because the forming of tea sediment is rather complicated and lacks satisfactory solution. And at present, most of tea beverage producers remove tea sediment or inhibit tea sediment formation by physically removal or chemically de-creaming. These methods not only cause a great loss of active ingredients and decrease healthy functions, but also influence the appearance and inherent quality of the products, and then hinder the development of Chinese tea-beverage industry. Tea cream, the turbid phenomenon produces when tea infusion cools, is the previous process of tea sediment formation. It was reported that tea sediment can be divided into reversible and irreversible sediment. And their chemical constituents, formation mechanism and influencing factors were distinctly different. In order to effectively control the sediment in tea beverage, this paper summarizes the chemical components participating in tea sediment formation, the factors and the mechanism of tea sediment formation, and the controlling methods.
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