Abstract:

The particle morphology and the superficial structure of lotus starch and different sizes of super-fine whole lotus powder were investigated by using optical microscope, scanning electron microscope, polarizing microscope and X-ray diffractometer. The results indicated that majority of the lotus starch granules displayed a smooth surface and were club-shaped and less was in oval or round shape. Obvious rings were observed and the particle centre was located on one side. Clear cross polarization were found and the big club-shaped starch particles were in “X” shape while the smaller round ones had vertical or declining cross and some of them are in the shape of “X”. Lotus starch granules exhibited a B-type in X-ray diffraction pattern. The structure of lotus starch granules in super-fine whole-lotus powder was damaged and only a few “X” or fragmentary “X” and cross could be observed. Reductions of crystal region and increases in non-crystal region were found with the decrease in particle size.

Key words: lotus starch, super-fine whole lotus powder, granule structure, granularity