小肽饲料营养价值及评价方法

The evaluation method for nutrition of small peptide feed

小肽一般是指二肽或三肽,小肽饲料就是通过化学或生物方法将本来不适合动物利用的蛋白原料分解,制成含有大量小肽的饲料产品。小肽饲料的营养价值在于小肽的吸收优势和其自身的质量。根据影响小肽营养价值的因素,可以选取小肽的总含量、平均肽链长度、特定小肽的含量、特定氨基酸的含量作为评价小肽饲料营养价值的指标。目前小肽含量的测定方法主要有双缩脲法、福林-酚法、三氯乙酸法、甲醛滴定法、凯氏定氮法、紫外光吸收法、消光系数法、考马斯亮兰法、层析比色法、高效凝胶色谱法、高效液相色谱法和CE-ESI-MS联用法。

Generally, small peptide includes depeptide and tripeptide. Small peptide feed, which contains a lot of small peptide, is produced with bad protein material by chemical or biological technique. The nutritional value of small peptide feed includes its advantage in absorption and its quality. Based on the facts which affect the small peptide feed＇s value, we choose total content of small peptide, average peptide length（APL）, content of special peptide, and content of special amino acide as the index to evaluate the small peptide feed. The main assay methods include Biuret method, Lowry method, trichloroacetic acid method, formol-titration method, Kjeldahl determination method, UV absorption Spectrum, extinction coefficient method, Bradford method, chromatography and spectrophotometry, HPGC, HPLC and CE-ESI-MS.