Abstract
Samples of ginkgo nuts were harvested 8 times in total during the period of July to October, 1987. The endosperm and episperm from ginkgo nut were separated. Lyophilized slices and starch granules were prepared from the nuts. Each slice was observed under photomicrographs and scanning electron microscope (SEM) and the properties of the starch granules were examined.
The results obtained were as follows :
(1) The most common particle size of starch granules of ginkgo nut was 6-8 pm on July 17 in endosperm, 10-20 μm after July 30 in endosperm and episperm.
(2) The susceptibility of starch granules of the episperm to hog pancreatin was higher than that of the endosperm.
(3) The initiation temperatures for gelatinization obtained by photopastegraphy were 66.0- 67.7°C for the endosperm starches and 59.3-59.7°C for the episperm starches and tended to be lower in the episperm starches than in the endosperm starches.
(4) The amylose content of endosperm starches determined by either amperometric iodine titration or enzyme-chromatographic method tended to increase with development of the endosperm.
(5) X-ray diffractograms of the endosperm starches changed from A type patterns to Ca type ones during development of the endosperm.
