We have seen how time and temperature are the two most critical aspects when it comes
to cooking. Manage them well and we can minimise the loss of nutritious substances;
conversely, excessively long cooking times and excessively high temperatures may not
only impoverish many foods, they might also lead to the formation of potentially harmful
substances. Other highly crucial factors to consider both before and after cooking are
exposure to air and light. For example, our habit of dicing up vegetables into very small
pieces, exposing a greater surface area to the air, can therefore also result in a greater loss of
vitamins such as vitamin C. The same principle applies when we prepare and chop salads
well ahead of time rather than leaving vegetables uncovered at room temperature and
therefore exposed to light and air. One key tip, therefore, is to prepare vegetables - whether
raw or cooked and wherever possible - just before eating them. Another important tip is
to avoid using excessive amounts of water to wash food, again primarily vegetables, and to
avoid soaking them for too long. This practice can also “wash” away some vitamins, such as
niacin and thiamine.
Remaining on the topic of water, it is good practice to reduce to a minimum the amount of water we use to cook vegetables, pasta and rice. With regard to vegetables, this will enable us to minimise the amount of vitamins and mineral salts that are lost in the cooking water, which can in any case be reused in stocks and soups. Rice and pasta, meanwhile, can absorb almost all of their cooking water in this way, again preventing amides, mineral salts and vitamins from being thrown away with the excess liquid. Finally, for foods that can be cooked in their skins, such as potatoes, we believe that this method enables nutritious substances to migrate within the food, thus greatly limiting their loss.