There’s an SF subgenre about a person from the present somehow being transported to the past. They then usually rely on their knowledge of some more advanced technology that they introduce to whatever era to make money and survive. We’ve discussed this subgenre before, so I don’t want to open that discussion again.
But I had the thought that there might be some technique to preserving vegetables/fruit which would not destroy vitamin C and which could be used for this purpose. Or maybe a way to make Vit C pills. The era in question will be some time before the 19th century, so the technique has to be fairly easily done with the technology of those times. I thought of simply drying the fruit, but raisins and prunes don’t have much vitamin C, so apparently that does not preserve the vitamin. Is there some other way?
Vitamin C (ascorbic acid) is more stable in lower pH environments - in the presence of other acids; so for example the citric acid that is naturally present in lemons, serves to stabilise the ascorbic acid.
Pickling in acidic solutions such as vinegar, or lactic acid would be one way to do it.
I question the need for such preservation, given that you can procure vitamin C in the dead of the winter in a Subarctic forest, or at the Arctic Ocean, for that matter.
But here was a Royal Navy surgeon in 1911 apparently ignorant of what caused the disease, or how to cure it. Somehow a highly-trained group of scientists at the start of the 20th century knew less about scurvy than the average sea captain in Napoleonic times. Scott left a base abundantly stocked with fresh meat, fruits, apples, and lime juice, and headed out on the ice for five months with no protection against scurvy, all the while confident he was not at risk. What happened?
Scurvy turned out to be the least of his problems.
And for the OP - does lime juice etc. keep? I know I keep my orange juice in th fridge. Do I have to, or is it just for taste? Or is Orange juice too sugary and not enough acidic?
The chenistry of Ascorbic Acid is pretty simple. Unlike proteins for example, it does not break down to parts. If the lactone part opens, it will just close again. I beleive it would just sit as uch in dried fruit. Chemistry of ascorbic acid - Wikipedia
It’s main use in our bodies is for collagen. Link below.
Well, something in the drying process seems to do something to Vit C. From da google:
1 plum (66 g) = 6.3 mg vitamin C
1 cup prunes (174 g) = 1 mg vitamin C
1 cup grapes (92 g) = 3.7 mg vitamin C
1 small box raisins (43 g) = 1 mg vitamin C
Plus you’d think if dried fruit would solve the scurvy problem, they’d have discovered it long before the 18th century when the benefits of citrus were discovered.
(BTW, modify the OP to mean the era in question was before the 18th century. I thought the citrus thing was discovered in the 19th not the 18th.)
Ascorbic acid oxidises and decomposes into other compounds such as oxalic acid (which, unlike vitamin C, is kind of bad for you)
Drying fruit probably increases the amount of contact between the molecules of ascorbic acid and oxygen or other oxidants, and if heat is used during the drying process, this will also increase the rate of the reactions that are breaking down the vitamin C.
For a pre-20th century method, pickling via a method that does not involve boiling/heating is probably the way to go. Lactofermenting seems the most obvious of these - sauerkraut, kimchi, etc
If we’re talking someone doing this with modern knowledge, I suspect that depending on where/when you were, you could preserve sliced lemons/limes in honey in sealed containers and preserve them a very long time. If nothing else because of the hydroscopic nature since any other features of honey preservation are subject to ongoing debate. And it wouldn’t require cooking/drying as mentioned above.
And honey would be available (although possibly/probably not cheap) in nearly ever age, climate and location on earth.
Sauerkraut was what Captain Cook used to preseve vitamin C for his voyages, probably because it wouldn’t degrade in that form. The use of lime juice and other substitues came later.
I find it ironic that people are subject to scurvy because our bodies don’t produce it themselves, as our ancestors could. Evidently, livin in a vitaminC-ricj environment, losing that gene didn’t have any ill effect on us. Until we started making long sea voyages and the like. Sailors fell to scurvy, but the rats on board – whose bodies could produce their own vitamin C – didn’t.
Similar things are seen in many animals. For instance, humans can produce taurine, because we need it. But it’s abundantly found in meat, and so animals that eat a lot more meat than we do, like cats, have lost the ability to produce it, because they don’t need to, because they get plenty from their diet.
The natural human diet includes a lot of fresh fruits and vegetables, which are rich in vitamin C. And so it was likewise no big deal when we lost the ability to synthesize it. Until we started radically changing our diet to do things like go on long sea voyages.
Given the moisture content of lemons, I’d have thought mixing then with honey would result in a concentration of sugars that is low enough to ferment.
Not sure it that would necessarily be a bad thing, but the high sugar concentration of honey is only really a preservative if you don’t dilute it.
depending on cultural backgrounds, Sauerkraut fullfilled the same historic function for seamen… and can easily be kept for a long time and is way more easily available in northern climates
*The Powerhouse of Vitamin C - Sauerkraut
Often, when we think about high-vitamin C foods, our minds jump to citrus fruits like oranges and lemons. But these common sources are not the highest in this essential nutrient. That title goes to sauerkraut a fermented cabbage dish that packs a whopping 700 milligrams per cup.
In comparison, bell peppers and medium orange which are often touted as top foods high in vitamin C only offer around 90 milligrams each.
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But I have the doubt that people THEN knew the whole Scorbut - Vit-C - train of thought … or if this discovery just happened by chance and people kept doing it. … Any info on that?
