Consuming nutritious foods is a very important part of a healthy lifestyle, it can improve our health status as well as our energy levels. However, before consumption, almost all food is processed in some form, be it slicing, blending or cooking and baking. Whatever the process, it is more than likely that the nutritional value of that food will change. Although there are differences between the techniques used in the kitchen, overall, it can be said that the processes that expose foods to high levels of heat, light or oxygen cause the greatest loss of nutrients.
Some vitamins are more stable than others. During food processing and storage, water-soluble vitamins (group B and C) are more unstable than fat-soluble vitamins (K, A, D, and E). During cooking, a small amount of water-soluble vitamins from vegetable fruits are leached into the cooking water. This is not a problem with soups or stews, because we also consume the cooking water, but when we don’t use it, the vitamin does go into the drain. Kale, broccoli, cauliflower, cabbage, zucchini, spinach and peas contain higher amounts of these vitamins. The good news, though, is that there are many foods rich in vitamin C and B vitamins that we eat raw (such as leafy salads, peppers, spinach, tomatoes, or fruits), so a balanced diet will cover your needs for those vitamins as well.
Then vegetables and fruits are always better raw, right? The reality is that while cooking can cause the loss of some vitamins and minerals, it also changes the structure of the cells and makes certain vitamins and nutrients more accessible to our bodies. This is true, for example of beta-carotene (a precursor for vitamin A), which can be found in carrots, pumpkins, or sweet potatoes. Furthermore, egg white is 180 times easier to digest when cooked than raw or, for example, potatoes, whose starch content can only be digested by our body after cooking.
It is important to mention that processing, whether industrial or domestic, in most cases is to our advantage. Whether it’s heat treatment to make the food safer or preserving to create a longer shelf life.
In summary, therefore:
- Depending on the method of processing, there is almost always some change in the nutritional value of the food.
- Water-soluble vitamins are most sensitive to processing and cooking.
- These losses can be reduced by more careful cooking and proper storage.