Qualification of Manufacture’s Labels Protein ContentTsion YohannesBiology 2107K LabOrezime UyehMarch 13, 2019AbstractThe central purpose of this experiment was to see if food companies accurate provide how much protein is in their products. This experiment was performed by using known protein concentrations to find the absorbance (OD595) with a spectrophotometer. A standard curve graph was created with this information. A factor of 50 diluted the three types of milk (Whole Milk, Fair Life Milk, and Muscle Milk). The absorbance found was used to determine their concentrations. The results showed that Muscle Milk's manufacturer label showed it had the highest levels of protein, yet experimentally showed that it contained the lowest protein content out of the others. The overall conclusion of the experiment showed that the hypothesis could not be refuted due to there not being multiple trials. IntroductionFood companies have such a significant impact on peoples’ lives. Their products are whatmany across the nation use to nourish their bodies properly. Therefore, their products should accurately represent what is present in their products. If food companies are not truthfully advertising what is in their food, then consumers that specifically by their food for what advertised would be blindsided on what they are consuming. With this information, this gained curiosity to whether manufacturing companies accurately provide the information on their nutrition labels. This information then posed the question of whether manufacturer labels are accurate. A device called the spectrophotometer measures the amount of light absorbed by a solution (Gutzler and Brewer, 2018). An indicator showed how much of the protein was present in the solution (Gutzler and Brewer, 2018). The deeper and darker of blue the solution became caused more light to be absorbed by the solutionwhich then told how concentrated the solution was. By using known protein concentrations placed in a spectrophotometer, the absorbance of light was found. This data then formed the standard curve. The milk absorbance was then found and solved by using the standard curve that was found. If the manufacturer’s labels are supposed to be accurate, then the label should have a low percentage difference from what was found experimentally. The prediction is that due to Muscle Milk’s manufacturer’s label displaying that the protein concentration is high then the percentage difference from the experimental concentration should be low.Methods (Gutzler and Brewer, 2018)Eight cuvettes were gathered and labeled “blank” and “1-7”. The “blank” cuvette gets 20 µL of the 1xPBS. The other cuvettes received 20 µL of their appropriate concentrations. Then, the dye reagent added to all cuvettes. The spectrophotometer absorbance was placed on OD595. The data gathered generated the standard curve equation. Next, there were four cuvettes, one labeled “blank” and received 20 µL of PBS. After the milk diluted by a factor 50, 20µL of the final solution was placed in a cuvette. All the cuvettes then received 1 mL of dye reagent. They were all then placed in a spectrophotometer that was at an absorbance of OD595. In this experiment, thecontrol group is the cuvette with PBS. The independent variable was the protein concentrations, and the dependent variable was the absorption.Results As shown in Figure 1, the protein concentration and absorbance are directly proportional. The absorbance of protein concentration at 1.500 mg/ml and 2.000 mg/ml were omitted due to being over 1.Table 1: Conversion of Protein Concentration from g/serving to mg/mlSample Protein Content on Product Label in grams/servingConversion of Protein Content into Concentration (mg/mL)Whole Milk 8/240 mL 33.3Fair Life Milk 13/240 mL 54.2Muscle Milk 20/330 mL 60.6As shown in Table 1, the protein concentration shown on the labels Whole Milk has the least amount of protein concentration compared to the other types of milk, while Muscle Milk has the highest levels of protein concentration.Table 2: Measured AbsorbanceSample Absorbance (OD595)Whole Milk 0.447Fair Life Milk 0.560Muscle Milk 0.424As shown in Table 2, experimentally, Fair Life Milk has the highest level of protein concentration out of all the types of milk while Muscle Milk has the lowest levels of protein concentration.Table 3: Calculating the Final Concentration of Samples by Taking into Account Dilution factorSample OD595Concentration(mg/mL) from standard curve Dilution factor Final Concentration of sampleWhole Milk 0.447 0.51 50 25.5Fair Life Milk 0.560 0.64 50 32Muscle Milk 0.424 0.49 50 24.5As shown in Table 3, the final concentration of the sample still show that Muscle Milk has a lower protein concertation while Fair Life Milk had the highest protein concentration. Table 4: Comparison of the Nutritional Label Information with Measured ConcentrationsSample Final Concentration (mg/mL)Protein Concentrationon Label (mg/mL)Percent DifferenceWhole Milk 25.5 33.3 -23.4%Fair Life Milk 32 54.2 -41.0%Muscle Milk 24.5 60.6 -59.6%As shown in Table 4, the final concentration of the Whole Milk was the closest out of all the kinds of milk to protein content printed on the label with having a 15.9% difference. The Muscle Milk was the farthest off from what was on the label with a 60.6% difference. ConclusionThe hypothesis of this experiment that if the manufacturer’s labels are supposed to be accurate, then the label should have a low percentage difference from what was found experimentally was not supported. The prediction that due to Muscle Milk’s manufacturer’s label displaying that the protein concentration is high then the percentage difference from the experimental concentration should be low was also not supported. Muscle Milk not only had the lowest experimental final protein concentration, but it also had the highest percentage difference out of the three kinds of milk. Whole Milk’s manufacturer’s label showed that out of the three types of milk it should have tested to contain the lowest protein concentration, yet, experimentally, had the second highest level of protein concentration and the lowest percentage difference at -15.9%. Experimentally, Fair Milk showed to have the highest level of protein concentration while the percentage difference was in between the other kinds of milk. The FDA (Food and Drug Association) regulate the food and drugs administered in the United States (Labeling