Rakshitha Madamakki

Foam index as a surrogate measure of protein content: an exploratory and inexpensive laboratory-free tool for students - P 495-504

An easily executable method to track nutritive potential of raw food grains at home is described here.
Blanching the soaked grains with the boiled supernatant aided the release of protein into the supernatant
which in-turn correlated with the protein content of
the grains analysed in this study. When agitated, the
supernatant generated stable froth, measured as foam
index (FI). When compared with standard protein
estimation methodologies (ultra-violet absorption and
Folin–Lowry), both the percentage volume of the water
absorbed (VA) and FI emerged as potential quantitative parameters. Correlation analyses using multiple
grains of varying protein content indicated that VA
and FI could serve as laboratory-free surrogate
measures of protein content, and therefore a reflection
of their nutritional value. To eliminate the possibility
of surfactant-mediated foam, an ink-based ‘dye diffusion test’ was developed, wherein the dye was significantly retarded by protein foam. The simplicity of
these assays were tested as a part of learning modules,
successfully executed even by school students (12–15
years old). Qualitatively, it engaged them in more authentic scientific inquiry in a way that was meaningfully associated with their daily lives. We propose that
this technique creates opportunities for participation
in citizen science, and can help address questions about
cultivar growth in different climatic conditions when
analysed temporally in a large networked format.


Froth, grains
protein estimation
home lab
nutrition