Here is a report entitled "Change in sodium content of potato, pasta and rice with different cooking methods".
So the "scientific answer" is:
- The sodium content in pasta cooked with different levels of salt increased approximately linearly with the amount of salt added to the cooking water. Pasta cooked in 4g salt/100g raw took up on average 28 mg Na/100g whereas when cooked in 40g/100g raw this increased approximately 10 fold to 230 mg Na/100g.
HTH!
PS: This may help you forget the Na intake temporally
Wetted starch is not the same thing as cooked starch. If you want to see the difference in a simple experiment, make two starch slurries, boil one into a pudding, and leave the other one cold. Starch only gelates at high temperatures (I think it starts around 70°C, but needs even more to complete the process).
When you have a grain of rice, you have the problem that the starch is very closely packed together, and water can't penetrate into the center of the grain too well - the outside layers soak all the water they come in contact with, and so water only seeps into the center of the rice after the outer part has been hydrated. It is similar for pasta. In the worst case, when you cook rice, the time needed for cooking will be enough to heat the whole grain to the gelating temperature, but not enough for the water to hydrate the innermost part of the corn. This is fine if you want hardish-cooked rice, but if you want soft, mushy rice, you should presoak it so the inside is already hydrated when you start cooking it. I suppose you can do the same with pasta. This is the reason why some sources will advice you to presoak.
But, as I said, this is not the same as cooking. Yes, the rice or pasta will get soft, so you won't break your teeth if you try to eat it. But it will still be raw starch. I don't know if it is unhealthy to eat raw starch (my mother certainly told me so, but it could have been a myth; I asked a question about that and got no conclusive answers). But it will probably taste unpleasant, similar to raw potatoes or raw flour. I would try to get other sources of food for this time period. Or, as @justkt's comment suggests, it is easy to get an electric kettle in a brand new house before the kitchen is installed. You can use it to pour cooking water over "instant" versions of pasta and rice. These have been pregelated and then dehydrated, so don't need a prologned cooking. They are usually available as instant hot soup or rice meals in sachets and cardboard boxes, I haven't seen them as pure ingredients.
Best Answer
For dried pasta it doesn’t really matter if you start with cold or hot water, as most of the time pasta spends in water is for hydration. And once the hydrated starches reach a certain temperature they gelatinize, thus cooking the pasta. When you start with cold water, you should use less water, which is actually a plus...
Note: I forgot to mention, you should swirl the pot every couple of minutes to prevent sticking.
However, when you’re cooking fresh pasta, you should directly start with boiling water. As it’s already hydrated, you just need gelatinization.
As for which you should do for dry pasta, there are benefits to both: