Implementation of Smartphone-Assisted Colorimetric Assay for Metabolite Measurement in Plant Extract: An Example of Controlled Release from a Polymer Matrix

Students' use of mobile phones has become common during their free time. Moreover, they can allow them to show advanced concepts and expand the capacity of high schools with limited resources. In this activity, high school students have used their mobile phones and two free applications to study the quantification and calibration of a natural extract of betalains obtained by themselves from beetroots. The extract was made after cut, grinding, and separated from the lipidic fraction with petroleum ether. Using a standard, their phones, and various dilutions, the students obtained a calibration plot (R-2 approximate to 0.95) and the concentration of the extract. Finally, using the spherification technique in calcium alginate, the concept of controlled release of drugs and/or nutraceuticals was shown with excellent results. This work opens the doors to expand the capabilities of educational centers in their laboratories and the possibility of using colorimetry of complex food matrices.