Cereal Chem 58:381 - 384.  |  VIEW ARTICLE
Effect of Microwave Treatment on the Microstructure of Dehulled Rapeseed.

P. N. Maheshwari, D. W. Stanley, F. R. van de Voort, and J. I. Gray. Copyright 1981 by the American Association of Cereal Chemists, Inc. 

The microstructures of Brassica napus c.v. Tower, B. campestris c.v. Candle, and B. juncea (oriental mustard), microwave-treated at 7, 10, and 13% moisture contents for durations of up to 2.5 min, were studied by scanning electron and light microscopy. The changes observed in the major cell inclusions, spherosomes (oil droplets) and aleurone grains, were a function of the extent of heating and included coalescence and loss of identity of spherosomes and distortion of aleurone grains. In samples in which myrosinase was completely inactivated by the microwave treatment, the membranes surrounding the spherosomes pulled away from the cell wall, cohered, and collected mainly in the center of oil-rich cells and around the aleurone grains in aleurone cells. Consequently, structureless areas filled with oil were formed near the cell walls. These microstructural changes provided an explanation for inactivation of enzymes and facilitation of oil extraction in rapeseed that may be applicable to other oilseeds heat-treated before crushing.