Hello, Scintissist. I'm looking for a quick and easy way to detect protein or nirogen levels in milk without using the Kjeldahl method, so do let me know if you know of any.
Colorimetric Protein assays....BCA, bradford, lowry, biuret...pretreatment may be needed to isolate the proteome and to get rid of interfering milk components (fats, carbohydrates mainly...)
There are various methods for analyzing the protein content in a food sample, where each method has their own pros and cons. For instance, in Kjeldahl method, we measure the Nitrogen content in the milk sample, where we may get the readings of Non-protein nitrogen as well which will results the crude protein content in milk. In case of following Infrared reflectance, it may give the true protein content in milk.
Hope the following source will be useful for you. Article Measuring Protein Content in Food: An Overview of Methods