tag:blogger.com,1999:blog-5784009899532873207.post8176710308585545602..comments2023-12-04T00:25:05.692-08:00Comments on Zestos: Enabling life through communication of research: Vitamin C variation in citrus fruitDavidhttp://www.blogger.com/profile/08195879878663722331noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-5784009899532873207.post-75595631348533235622009-07-14T21:59:09.112-07:002009-07-14T21:59:09.112-07:00Keith
Great question. Tiffany recons that they p...Keith <br /><br />Great question. Tiffany recons that they put citrus tree in pots and watered them with wine.<br /><br />On a more scientific note.... <br /><br />You are right to say that vitamin levels decay rapidly. Although some nutrient decay linearly, that is the same amount every day, most tend to follow exponential decay. Exponential decay is rapid to start with and then slows down. Let us take a hypothetical situation of exponential decay with a 50% reduction daily. So we pick an orange and it has 100mg of Vitamin C, tomorrow it would have 50% which is 50mg. The next day it would drop 50% so it would have 25%, next day 12.5%, next day 6.25%, 3.125 then 1.5625 and now I can't do the numbers in my head.<br /><br />Typically the decay wouldn't be 50% a day, and tends to a low but still measurable base line. <br />What this example shows is that there is a low residual level that will be in the fruit for a very long time. <br /><br />Now couple this low residual vitamin C intake needed to prevent scurvy. The following details are known:<br /><br />The average person only needs 10mg of Vitamin C per day to prevent scurvy for a year. (Wohl & Goodhart pg 301)<br /><br />A man with scurvy was cured with 6.5mg vitamin C daily. (baker et al American J of Clinical Nutrition 1969)<br /><br />"The minimum requirement for Vitamin C in adults must consequently be somewhat below 10mg a day, and some test results seem to indicate that is is about 5mg a day" Uhil American J of Clinical Nutrition 1958)<br /><br />So you can see that you hardly need any vitamin C in your diet to prevent scurvy. <br /><br />I don't have any data currently upon the vitamin C decay rates in citrus stored in a unrefrigerated environment. If we take the "average" orange of 70mg exponential decay after say 6 months I would not expect there to be less than 10% remaining eg 7mg of vitamin C which would prevent scurvy. <br /><br />Also remember that when on shore the vitamin C levels would increase with the better food, so it would take a while to decrease the bodies storage levels down to the very low level that creates scurvy. <br /><br />Hope this answers your questionDavidhttps://www.blogger.com/profile/08195879878663722331noreply@blogger.comtag:blogger.com,1999:blog-5784009899532873207.post-88571166260832916512009-07-11T18:14:14.378-07:002009-07-11T18:14:14.378-07:00I have heard that a huge percentage of vitamin C i...I have heard that a huge percentage of vitamin C is lost the moment you pluck the fruit from the tree and that it continues to decline quickly over time. Hence one of the advertised reasons to take vitamin C suplimentation. Given the poor storage facilities and unseasonal seasons encountered by early sailors, how did the "very old" fruit provide sufficient vitamin C to eliminate scurvy? Can you enlighten me! Thanks David.keithlightfoothttps://www.blogger.com/profile/16174128367794498401noreply@blogger.com