【摘要】 鲜棗的抗坏血酸含量极高,为一般水果与蔬菜之冠。品种之间的差异很大。在本试验里所分析的16种鲜棗,一般含量都在每百克300毫克以上,多数在400—600毫克之间,最高者则超过1,000毫克。含量随成熟程度而降低;当棗由硬变软时,还原抗坏血酸之量大减,脱氢抗坏血酸之量相应地增高,而总抗坏血酸之量则无大改变。在冷藏 坏血酸的利用率为纯抗坏血酸的72.6—100.5％,平均为86.3％,这样的差异是不大的。更多还原

【Abstract】 Jujube(Zizyphus vulgaris Lam)is a popular fruit in North China. The fruit is mainly marketed after dehydration. However, there are no less than twenty rarities sold in Peking while fresh during the months of August and October.The ascorbic acid content of 16 varieties of the fresh fruit has been determined. The values found are all above 300 mg per 100 g of edible portion—mostly between 400-600 mg, the highest being above 1,000 mg. It is certainly worth noting that, as a class of ordinary food, Jujube has the highest ascorbic acid content.As the fruit ripens, i. e. the colour turns from green to red and the texture changes from hard to soft, its ascorbic acid content decreases. When the sample was stored at 0-4℃ for about one and a half months, the fruits which remained hard lost about 10％ of its ascorbic acid; when the fruit had become somewhat soft, the amount of ascorbic acid decreased drastically and the dehydro-form increased correspondingly while the total amount remained practically unchanged.Experiment with human subjects indicated that the utilization of the ascorbie acid of Jujube is 86.3-93.0％ of the pure vitamin.更多还原