Student Research Projects

A Comparison of Total and Essential Amino Acids in Generic Brand Soy and Whey Protein Powders

Student Joanna Clark, '16
Faculty Mentor(s)
Department Chemistry
Course Chemistry 480: Instrumental Methods of Analysis


Supplementation is commonly used in dietary regimens to help increase the amount of desired nutrients. Protein powders have been on the market for many years and all claim to contain the best types of digestible proteins. An ideal protein powder contains essential amino acids and both plant and animal based proteins state to contain these desired macro nutrients. It was hypothesized that the animal based proteins would contain more essential amino acids compared to that of plant proteins. To test this hypothesis, generic soy isolate protein powder and pure whey protein powder were tested by isolating the amino acids and reacting the amino acids with ninhydrin to produce a color change representing the total amino acid content within a sample. The change was monitored using Ultra Violet/Visible Light Spectrometer recording the absorbance at 579nm. A two dimensional chromatographic analysis was completed to differentiate the essential amino acids and to provide semi-quantitative results on which product provided a wider variety of essential amino acids. Total amino acid (mg amino acid per mg of protein) for soy and whey powders was found to be 0.2 and 0.21 respectively. The separation of individual amino acids in the samples was unsuccessful. Further studies should be completed to determine essential amino acid content within the different samples.