I have seen some recipes saying you can cook fries with coconut oil. The temperature for fries seems to be 350f however this is also the smoking point for unrefined coconut oil.
Does this mean you cannot cook fries with unrefined coconut oil and perhaps these recipes are referring to the refined type?
Use the refined coconut oil. And not only for temperature reasons...
I admit to not liking the taste of coconut in many cases... but I particularly don't want my french fries tasting like them. That may not be universally the case for all people, but if you want a neutral-flavored oil, unrefined coconut oil is not that. You will end up tasting only coconut, not french fry.
This site seems to agree:
Don’t get me wrong: I really dig the occasional coconut macaroon or coconut cream pudding. But I don’t want coconut flavor invading my scrambled eggs, fresh popcorn or homemade chicken broth. And neither does the rest of my family.
We tend to eat more coconut oil when it’s refined and flavorless, because it’s so much easier to blend into any kind of dish.
If you love coconut-flavored anything, then this probably isn’t a big deal. But if you’re like me, refined coconut oil simply fits into your life more seamlessly. Frankly, we’d barely touch our coconut oil if it was the unrefined variety. So I choose refined because I know we’ll actually use it.
Extra virgin coconut oil has a relatively low smoking point of 350 degrees F. This is pretty low as far as a cooking temperature goes. If you’re eating your oil raw or using it mostly for baking, this is probably not an issue. But for stovetop cooking, this is generally too low of a smoking point.
The most important thing you need to understand is that, contrary to popular belief, the smoke point of an oil has nothing whatsoever to do with how well it resists heat; oils smoke primarily due to the presence of free fatty acids and particulates, whereas what you're really after is how resistant the oil is to oxidation. This is almost entirely determined by its fatty acid composition, with saturated fats being the by far most resistant, monounsaturated fats being less resistant, and polyunsaturated fats being the least resistant of all. This is also quite noticeable from how quickly the latter go rancid, in contrast to how the former can be stored for many years without going rancid at all. That is why coconut oil, being very high in saturated fatty acids, and the small remainder being monounsaturated fatty acids, is exceptionally resistant to heat.
The subsection "Oxidative stability" on the Wikipedia article "Smoke point" explains it quite well:
Hydrolysis and oxidation are the two primary degradation processes that occur in an oil during cooking. Oxidative stability is how resistant an oil is to reacting with oxygen, breaking down and potentially producing harmful compounds while exposed to continuous heat. Oxidative stability is the best predictor of how an oil behaves during cooking.
The Rancimat method is one of the most common methods for testing oxidative stability in oils. This determination entails speeding up the oxidation process in the oil (under heat and forced air), which enables its stability to be evaluated by monitoring volatile substances associated with rancidity. It is measured as "induction time" and recorded as total hours before the oil breaks down. Canola oil requires 7.5 hours, for example, whereas extra virgin olive oil (EVOO) and virgin coconut oil will last over a day at 110 °C of continuous heat. The differing stabilities correlate with lower levels of polyunsaturated fatty acids, which are more prone to oxidation. EVOO is high in monounsaturated fatty acids and antioxidants, conferring stability. Some plant cultivars have been bred to produce "high-oleic" oils with more monounsaturated oleic acid and less polyunsaturated linoleic acid for enhanced stability.
The oxidative stability does not directly correspond to the smoke point and thus the latter cannot be used as a reference for safe and healthy cooking.
