Quantitative Analysis of Starch in Dietary Supplements PDF

Preview

Summary

Quantitative analysis dietary supplements post-lab...

Description

Quantitative Analysis of Starch in Dietary Supplements A fitness club that previously inquired into whether some dietary supplements contained filler substances other than proteins now wants to know how much starch these supplements contain. The information they received previously was qualitative data because we simply tested if the dietary supplements contained substances other than protein—like starch, carbohydrates, and sugar. Now, they are requesting quantitative data since they want to know how much starch is in the supplements. Finding this information will allow the fitness club to determine if the supplements are misrepresented when advertised which will determine whether they will advertise the product. We created a Concentration vs. Absorbance graph with a best-fit line after we mixed varying levels of starch (0-4 mL) with 1 mL of Lugol’s reagent in test tubes and measured absorbance values using a spectrophotometer. We tested absorbance of starch in the supplement samples by adding 1 mL Lugol’s reagent to 4 mL of each sample and again got the absorbance values using a spectrophotometer. Using these absorbance values and the graph, we were able to find the approximate unknown concentrations of starch in each of the three samples. It was given that the concentration of each supplement was 0.3 g/L and using that, we were able to determine percentage of starch in each sample. Our findings showed that sample 1 contained 0% starch, sample 2 contained 11% starch, and sample 3 contained 7% starch. This shows that one of the samples have no starch while the other two of the samples have a small amount of starch meaning it is alright for the fitness club to advertise the products if they are solely basing their trust on if the supplements contain a low amount of starch. However, there is evident study that suggests protein supplements do not affect muscle mass (Nissen and Sharp, 2003). Therefore, the fitness club may think about reconsidering. Additionally, there may be other substances that may not have been tested for, such as pro-oxidant transition metals, (Morbeck, 2014) that may also be included in the supplements and thus, lead to a smaller concentration of protein. Concentration (g/L) of stock 0 .02 .04 .06 .08

Absorbance 0.314 0.601 0.938 1.234 1.595

Concentration vs Absorbance of Stock 1.8

Concentration (g/L)

1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

Absorbance

Sample

1 2 3

Unknown Concentration of Starch 0.0000 0.0330 0.0210

Absorbance

% of Starch in Sample

0.233 0.875 0.646

0% 11% 7%

When determining the unknown concentration of starch in the three samples, we had to rely on a best-fit line based on the concentration vs absorption values of the stock solution. Due to this, it is possible that the best fit line was a little bit off. Also, due to relying on the best fit line, the concentration had to be approximated so we do not know the exact concentration of starch in the samples, only an estimate. We were able to successfully carry out the experiment desired by the fitness company. Our quantitative analysis displayed the concentration of starch in each supplement sample based on absorbance values produced by a spectrophotometer. Although the values were not exact, they were close enough to determine relative starch percentages in the samples.

Citations:

Nissen, S.L. and Sharp R.L. 2003. Effect of dietary supplements on lean mass and strength gains with resistance exercise: a meta-analysis. J Appl Phisyol.

Morbeck, D.E., Paczkowski, M., Fredrickson, J.R., Krisher, R.L., Hoff, H.S., Baumann, N.A., Moyer, T., Matern, D., 2014. Composition of protein supplements used for human embryo culture. J Assist Reprod Genet. 31(12): 1703-1711....