To investigate the effects of parboiling on protein and starch constituents of black and red rice grains, 10 rice kernels were fixed, cut into midsections and left in the fixative solution overnight. The fixative solution was composed of 2% Formaldehyde, 2.5% Glutaraldehyde, and 2.5 mM Calcium Chloride in 0.1 M Sodium Cacodylate with a pH at 6.9. After fixation, the kernel midsections were rinsed in 0.1 M Sodium Cacodylate and dehydrated in a graded ethanol/butanol series, followed by infiltration with Technovit 7100 monomer (with hardener) and placed in the fridge to polymerize.
Plastic molds were trimmed down and sections of 2 lm and 4 lm were made with a rotary microtome for sample staining. Aleurone layer and endosperm were identified by staining in Periodic Acid-Schiff’s counterstained using 1% Alcian Blue B in 3% acetic acid, and viewed in brightfield. The samples were viewed and photographed using a Leica DM4000B compound light microscope and their digital images collected using a digital camera.