Host: The Japan Society of Cookery Science
Pumpkins ripen in storage after harvest. Starch-storing cells and storage starch in uncooked and cooked pumpkins obtained in September (harvest time) and in December (storage) were examined by histochemical methods. Starch granules of the ripe pumpkin stored were smaller in number than those of the unripe pumpkin in harvest time. Starch-storing cells were filled up with gelatinized starch in the cooked unripe pumpkin. Many starch-storing sells had several lumps of gelatinized starch in the cooked ripe pumpkin; they were not filled with gelatinized starch. The cooked ripe pumpkin was less in quantity of starch than the cooked unripe pumpkin. Starch-storing cells of the cooked unripe pumpkin had starch composed of a long chain of glucose polymers. Starch-storing cells contained starch of a long chain and shorter chain of glucose polymers in the cooked ripe pumpkin. The starch transferred from starch-storing cells existed in spaces among them in the boiled ripe pumpkin, which did not taste sweet, but was rarely found in the steamed ripe pumpkin, which tasted sweet. The reason why the steamed ripe pumpkin tasted sweet was that glucose and sugar produced from starch hydrolyzed by starch-splitting enzyme remained in starch-storing cells.
