Résumé
The vitamin C content of dateplum persimmon's leaves (Diospyros lotus) collected and processed in some months (May, Jun., Aug., Sept. and Oct.) was determined. It was found that the amount of vitamin C in these products was 2045, 2540, 2650, 2680 and 310 mg per 100 gm respectively. They were all extremely rich in vitamen C and had an average about 2500 mg per 100 gm except that processed in Oct., of which the vitamin C content declined sharply.Observation on the stability of vitamin C in the products packed with several methods and stored in different conditions and durations showed that various environmental factors exerted a considerable influence on vitamin C retention to a certain extent, especially the sunlight and relative humidity which caused seri-ous damage. In general, the vitamin C retention of products packed with various methods were above 75% after two months of storage. Even when the Product was packed by plastic film bag and stored in ordinary condition, the remaining vitamin C was still above 800 mg per 100 gm after six months.After brewing of the product for 5-10 minutes just like making tea, the percentage of vitamin C extracted was about 75% in the first brewing and 11.5% in the second. The total amount of vitamin C extracted in two brews was about 85%.