Proteins are important for genetics and nutrition. The document describes an experiment using spectrophotometry to measure the protein content of evaporated and fresh milk by creating protein standards to generate a linear regression model for determining protein concentrations in the milk samples, which were then compared to nutritional label concentrations.

1. Got Protein? By Dr. Ricardo Chiesa<br />Proteins are very important not only in genetics but also in the nutrition of all the organisms. In order to identify if a product is rich in proteins or not, you can do a spectrophotometry experiment. That is what we did. First of all, we obtained a source of protein. In our case, the source of protein was different types of milk. Valeria and I tested the Evaporated and Fresh Milk using this technique. Because we used the spectrophotometry technique, in order to get the concentrations of the solutions we had to do a linear regression with seven standards. These standards were the control groups that indicated to us the different absorbance and consequently the concentration of proteins. Our experimental group was Evaporated and Fresh Milk. First, we observed qualitatively if there was a similarity between the standards and our experimental group. This observation was based on a color change. Then, with the linear regression calculated using the seven standards, we identified the specific concentration of protein of our experimental group. Finally, we contrasted the concentrations that we obtained with the concentration reported on the nutritional label of the evaporated and fresh milks respectively. <br />Carlos Santos Perez<br />804-10-8280<br />University of Puerto Rico<br />Cayey P.R.<br />