2023 Undergraduate Research Showcase


Analysis of Proteins in Bovine Milk Using HPLC, TKN, and MIR for the Application of Chemometrics

Document Type

Student Presentation

Presentation Date


Faculty Sponsor

Dr. Owen McDougal


The protein content of bovine milk is important information for dairy industry professionals as well as nutritionists and food scientists because milk serves the role of an important source of nutrients. As a result, an accurate and reliable method for the analysis of milk protein is necessary for product development. It is hypothesized that mid-infrared spectroscopy (MIR) is a fast, accurate, and cost-effective analytical method for the proteins found in milk which could be made further utilizable with the application of chemometric techniques. In this study, MIR is investigated as a potential supplementary analytical method for the protein of bovine milk. An acid precipitation was performed in skim milk samples, which were then analyzed quantitatively and qualitatively using three analytical methods. High-performance liquid chromatography (HPLC) was used to separate and quantify different proteins in skim milk samples. The total Kjeldahl nitrogen (TKN) method was used to determine the total nitrogen content of skim milk samples, which was converted into total protein content. MIR was used to obtain spectral data of skim milk samples for the application of chemometric methods. It was found that the HPLC method was able to provide accurate and reliable measurements of individual protein fractions, and the TKN method provided accurate and reliable measurements of total protein content. MIR spectra showed amide peaks of interest which correlate with specific proteins and were analyzed qualitatively. It was concluded that MIR is an underutilized method, and in combination with chemometrics could be a fast and accurate method for the analysis of protein in milk.

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