Studies on Constituent Variation during Storage after Freeze-Drying of Chestnut

The edible portion of chestnut, Castenea crenata Sieb, et Zucc, were freeze-dried and subjected to analysis of minerals, lipid classes and fatty acid composition by silicic acid column chromatography and gas-liquid chromatography. The results of analysis for the minerals in chestnut showed that the contents of magnesium, iron and phosphorus were decreased during storage after freeze-drying. The contents of neutral lipids, glycolipids and phospholipids in the raw edible portion were 34.6, 38.6, and 26.8%, respectively. The contents of neutral lipids and phospholipids of the freeze-dried chestnut were decreased, while glycolipids were increased during storage. In the fatty acid composition of total lipid, , and acid were abundant in the raw edible portion, but freeze-dried chestnut contained relatively much amount of , , and acid. It is noticeable that and acid in the freeze-dried chestnut were remarkably decreased during storage. Upon the fatty acid composition, total lipid contained and acid in the highest proportion, but neutral lipids, glycolipids and phospholipids contained and acid in the highest proportion. Cycloartenol (20.6%) was a major component in the 4-monomethylsterol fraction separated by thin layer chromatography and cyclolaudenol, cycloeucalenol, and citrostadienol were detected as minor components. Sitosterol (74.6%) was a major component in the 4-desmethylsterol fraction separated by thin-layer chromatography and , campesterol, stigmasterol and brassicasterol were also detected as minor components.