Amaranth nutritional value has been widely recognized, but the required
conditions for its processing cannot be adapted to traditional technologies. For the
proposal of alternative strategies, the changes of several components should be
understood. Enriched starch and lipid–protein fractions of amaranth flour upon
different milling treatments were obtained and characterized by attenuated total
reflectance–Fourier transforminfrared spectroscopy. Starch and lipid–proteinenriched
amaranth fractions were obtained by abrasive milling; amaranth starch
was isolated by wetmilling procedure, and flour samples were obtained from
planetary ball milling. Changes on starch, protein, and lipids relative contents, on
starch crystallinity and on lipids and protein stability after milling and 6month
storage, were evaluated. The Fourier transforminfrared (FTIR) spectroscopy
peaks of the main grain components were identified in the middleinfrared range.
By calculating the ratios between height intensities of selected specific peaks,
several characteristics of the samples could be explained: increased protein content
and lipid proportion of the enriched fraction; decrease of the starch crystallinity
degree by abrasive milling and especially by ball milling due to starch
amorphization during these processes; and lipids modification in milled and in 6
month aged samples. FTIR analysis can be considered a rapid, nondestructive,
solventfree, sensitive, and useful tool to investigate starch, lipid, and protein
modifications provoked by processing and storage as well as to determine, based
on intensity ratio, the relative proportion of grain components within amaranth