摘要
论证并建立差量法测定发酵豆粕类肽氮的含量。用pH8.0的Tris-HCl缓冲液浸提发酵豆粕样品,将浸提液的pH值调节到4.5,上清液为可溶性的肽和氨基酸;先称取一定质量的发酵大豆样品,再用酸沉淀法去除浸提液中大分子蛋白,并用自动凯氏定氮法测定上清液中的总氮含量,甲醛滴定法测定游离氨基酸态氮的含量,扣除游离氨基酸态氮的含量,得到肽氮的含量。方法简单易行,准确可靠,具有较高的应用价值。
The determination of peptide nitrogen content in the fermented soybean by difference method was demonstrated and established. Tris-HCl solution（pH8.0） was used as extraction buffer,when the pH value was adjusted to 4.5, the main nitrogenous substances presented in the supernatant were soluble peptide and amino acid;A certain amount of fermented soybean meals samples was first measured, then the macromolecular protein was removed by acid precipitation method and the total nitrogen content in the supernatant was determined by Kjeldahl method, after that the free amino acid nitrogen content was assayed by formol titration method. The content of peptide nitrogen was calculated by subtracting free amino acid nitrogen content. The method is simple, accurate and reliable, with higher application value.
出处
《粮食与饲料工业》
CAS
2015年第2期58-60,共3页
Cereal & Feed Industry
关键词
差量法
发酵豆粕
肽氮
测定
浸提液pH值
difference method
fermented soybean meal
peptide nitrogen
determination
extraction buffer pH value
