Testing to Find How Much Protein Is in 1% Chocolate Milk Versus 2% White Milk

Testing To Find How Much Protein Is In 1% Chocolate Milk Versus 2% White Milk.

Karlee Hensley, Candra Francis, Chelsea Kimmel, Sarah Mailloux

Abstract

Milk is a great source of protein for humans and other mammals. In this experiment, the amount of protein in Dean's 1% low fat chocolate milk and a 2% reduced fat milk were tested. The milk solutions were diluted and a Bradford reagent was added to each of the samples. Those samples were put through a spec that determined the concentration of the samples. The milk samples were compared to other samples that used the Bradford reagent supplied by the instructor. The hypothesis was that chocolate milk would have more protein than white milk. After receiving the results, neither the chocolate milk nor the white milk was found to have a higher concentration than the other, indicating the presence of more protein. This goes along with the nutrition labels facts supplied by Dean's Milk Corporation for both milks, but the findings have more protein than Dean's milk says the samples do. This difference is likely caused by human error. Therefore, our hypothesis was not supported because each of the milks had the same protein amount.

Introduction

In the Neolithic Era, 10-12,000 years ago, people began domesticating animals for use of food (How Milk is Made). It would have not been plausible to milk a wild animal, so domestication was required before people could drink the milk of the animals. Once these humans were able to be close to these animals, they began milking them and found out if was a great source of food. At first horses, bison, and caribou were milked, but in the end it was cows milk that held its ground as the primary milk source for humans.

As humans have evolved into a health conscious population, they began to see the importance of protein on a hard working person's diet. Protein is the body's prime building material. Enzymes, hair, skin, blood, and connective tissues are all constructed of protein. Protein also plays a role in numerous functions, including healing wounds, immune function, and the maintenance of body tissues. It is capable of decreasing blood pressure, lowering cholesterol levels, and lowering glucose levels (Sciverse).

The Bradford reagent is an assay that uses an analytical procedure to measure the concentration of a protein in a solution (Sciverse). The Sciverse website states that the Bradford reagent involves the binding of Coomassie Brilliant Blue G-250 to a protein. This binding causes a shift in the absorption maximum of the dye (Sciverse). This dye is only good for color stability for up to one hour. A great thing about the Bradford reagent is that it allows little to no interference from other cations. The Bradford reagent utilizes buffer controls that make the results more accurate.

The purpose of the present experiment was to determine how much protein was present in Dean's 2% reduced fat white milk and their 1% low fat chocolate milk. Protein is a necessity in one's diet from day to day. The tests were to see just how much protein is in these types of milk. The hypothesis was that chocolate milk would have more protein than the white milk, but this hypothesis was not supported by the tests.

Materials and Methods

Table 1 Spectrophotometer Table 2 Vortex Mixer

1% low fat chocolate milk and 2% reduced fat white milk were purchased at the store. Both milks were measured out by micropipettes so there were 20 μL of each in a separate cuvette. A 1:50 dilution was made for each of these substances. Next, a Bradford reagent was made. This was done by utilizing the micropipette, adding 4μL of chocolate