Does anyone know if the carb content of fruit when dehydrated is the same as the amount when fresh?
Just planning a keto orange cake for a birthday and we have tonne of oranges in the garden. I was thinking of using a little of the juice and either zest, or potentially dehydrated slices and turned into citrus dust. Orange extract isn’t something I can buy locally unfortunately
Any thoughts?
Dehydration removes water, not carbs. If you extract the juice first, however, you will remove most of the ‘simple’ carbs, leaving mostly starch and cellulose.
Drying fruits concentrates the sugars in them. For example fresh grapes at 16 g per serve, dried it turns into 76 g per serve (from e ditch the carbs website).
Zest is probably ok, you don’t add that much of it to anything. A tablespoon or so of orange juice would probably fit within a daily carb limit. (The fructose is another issue.) You might try this recipe. https://www.buttertogetherkitchen.com/low-carb-orange-creamsicle-cake/
If you have a lot of oranges, I suggest gifting or bartering them for other produce with your friends.
A couple of things to think about.
You have oranges. Use them. They are a wholefood. They are a wholefood source of carbohydrates. As they are not a packaged industrial processed food, you are on a win. If they are from your garden then it is likely that you know what went into producing them.
In a cake the problems come from the refined flour and refined sugar (including in frosting or icing). That area of cake deconstructionism would be the more interesting thing to look at. Is there yogurt in the recipe.
The way to deal with extra sugars in fruit for a keto-practitioner is fermentation. Let the bacteria and yeast predigest those sugars before they go inside the low carb eating human.
It’s a birthday. A downside of following a strict ketogenic regimen is the social impacts on the keto practitioner’s psychology. I think it is OK to make the cake. If you want to eat a piece of cake, do that as well. Wholefood, home grown orange birthday cake is a once-a-year food.
I assumed the carbs stayed the same as the fresh mass but just wanted confirmation.
The cake would be a keto fudge cake that is almost a chocolate truffle with a little coconut flour to bulk it out. I’ve made it before and omg is it indulgent. I think I’m going to just use zest to get the flavour in there.
Oh I like the idea of bartering, I need to find someone with an avocado tree. We have 2 orange trees, 2 pomegranate, 1 huge persimmon and 1 fig (non are keto sadly 
) but no avocado. I haven’t dug the ground over yet to make a veg patch yet so maybe I can find someone who has some brassica or beans growing if avocado are too precious
In my opinion, the zest is where all the yummy orange flavor is. I looked up the carb content, and apparently the carbs are negligible. Your cake sounds delicious!
I like the KF custom of a steakcake on our birthday and forum anniversary. (Just sayin’, lol!)
And as my general comment on the thread, even Dr. Robert Lustig, the anti-fructose activist, says that whole fruit is acceptable, since the fibre in the fruit slows down the absorption of the fructose to a rate that the liver can safely handle. (“God gave us the poison, but he also supplied the antidote,” he says.) Pulping the fruit to make juice destroys the fibre, which is why Dr. Lustig’s paediatric obesity clinic doesn’t allow their patients to drink anything other than water or milk. It is difficult to eat the number of whole fruits in one sitting that it takes to produce a reasonably-sized glass of fruit juice.
The only thing that goes away is the water, and perhaps some of the more fragile, water-soluble vitamins like C. So all the carbs will remain in the fruit (digestible carbs as well as fiber).
The big carb issue with dried or dehydrated fruit is that they are so concentrated and easy to eat. 100g of fresh fruit has a lot of water. 100g of dried fruit has almost no water, so more of the material that you eat is food energy (in sugar form). Most people will be able to eat more energy when their fruit is in the dried form for this reason.