花生蛋白多肽饮料肽含量测定重复性差原因研究

对经TCA沉淀、用双缩脲法测定花生蛋白多肽饮料中肽含量重复性差原因进行研究,从沉淀时间、TCA浓度及与样品体积比、离心速度和时间、放置时间、显色时间及反应体系pH几方面因素进行探讨。研究表明,处理液中TCA浓度在0.30 mol/L~0.43 mol/L范围内,沉淀和放置时间对肽含量不具有显著性影响;在11 000 r/min,10 min下离心,静置30 min,与双缩脲1∶3反应,肽含量稳定。

Study on reason of repeatability bad on determination of peptide content in peanut protein polypeptide beverage

This article researches the reason of repeatability bad on the determination of peptides content using biuret method.Study the following aspects as precipitation time、TCA concentration、the proportion between TCA dosage and sample dosage、centrifugal speed and time、keeping time、color reaction time,as well as pH values of the reaction system.Research shows when treating sample has 0.30 mol/L~0.43 mol/L TCA,precipitation and keeping time have no significant effect.Centrifuging 10 min under 11 000 r/min,colorizing 30min,the peptides contents keep stable,in 1∶3 reaction ratio between treating liquid and biuret reagent.