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VI. Evaluation
On the chromatogram you can see several spots in various shades from red to violet. The glutamic acid
standards are shown in lanes 6, 7 and 8 of fig. 1. The glutamate in the samples (here in this aqueous envi-
ronment as glutamic acid) runs on the same level as the standards, which makes it easily identifiable. By
comparing the spot size of the sample with the spot sizes of the standards, the amount of glutamate in the
samples can be semi-quantitatively estimated. The spots above and below the third row represent different
amino acids that cannot be identified with this kit system.
Figure 1: Example of a chromatogram with samples (lanes 1-5) and three glutamic acid standards (lanes
6-8). Concentrations of glutamic acid standard: 0.2 mg/ml, 0.33 mg/ml and 1 mg/ml. The sample in lane 1
contains no glutamic acid, the samples in lanes 2-5 show varying amounts of glutamic acid. The estimation
of the amount of glutamic acid shall be carried out in comparison with the standards.
VII. Suggestions and Questions for the Integration into Teaching
Preparatory work before the lesson:
1 Do some research on the topic „The flavour enhancer glutamate.“ (Alternatively, a lecture on the sub-
ject might be prepared and held by a student or teacher.)
2 Do some research on the topic of „TLC“. (Alternatively, a lecture on the subject might be prepared and
held by a student or teacher.)
3 For the next lesson, bring a small amount of food into the classroom, for which the presence of the
flavour enhancer glutamate shall be investigated.
Tasks during the lesson:
1 Read the entire experiment. Clarify questions with your neighbour.
2 Explain the function of the glutamic acid standard.
3 Justify why three glutamic-acid standards of different concentrations are used.
4 Describe the experiment’s underlying issue.
5 Carry out the experiment.
6 Log the experiment. Attach the chromatogram with tape to your protocol and label it.
7 Evaluate the experiment with regard to the question in task 2.
8 Check results you did not expect at all by searching for possible errors in the experimental procedures.
Please read the manual again. If necessary, run the experiment once more.
Tracking Flavour Enhancers
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