单宁广泛存在于植物界中,并分布在植物的多个组织器官中,按其结构和性质可分为水解单宁、缩合单宁以及复杂单宁.单宁是植物性饲料原料中一种重要的抗营养因子,其对动物的抗营养作用主要表现在降低动物摄食率,降低营养物质的生物利用率及产生毒害作用等方面.单宁降低营养物质生物利用率的主要原因表现在:降低营养物质的消化与吸收;降低动物体内的氮平衡;改变动物消化道菌群;单宁能损害消化系统等方面.单宁的去除方法主要有理化方法和生物降解法.理化方法主要包括溶液浸提、干燥、脱壳、挤压、碱、聚乙二醇以及射线处理等.生物降解法主要是固态发酵法.本文综述了单宁的抗营养作用及去除方法.%Tannins are a complex group of plant secondary compounds widely found in plant kingdom.Tannins mainly exist in various organs and tissues of plants. Tannins are conventionally classified into three groups: hydrolysable tannins, condensed tannins and complex tannins, according to the structures and properties. Tannins, as important anti-nutrients, exhibit detrimental effects to various animals by reducing voluntary feed intake, nutrient bioavailability and toxicity. The mechanisms of reducing nutrient bioavailability to animals were reported mainly as decreasing digestibility and absorption of nutrients, decreasing nitrogen balance in animals, changing microorganism diversity in the gastrointestinal tract, and producing toxicity to digestive systems. Treatments including physical-chemical and biological processes were reported to successfully avoid negative effects of tannins. Physical-chemical treatments mainly are soaking, drying, de-hulling, extruding, alkali treatment, polyethylene glycol (PEG) treatment and radiation. The biological treatment meanly includes solid-state fermentation. The anti-nutritional effects and methods of degradation of tannins are reviewed in this article.
展开▼
