Both fruits and vegetables are our main source of several vitamins. In particular, they provide almost all of our vitamin C, much of our folic acid, and at least half of our vitamin A needs. Leaves and other plant parts are also full of antioxidant compounds that give color to many fruits and vegetables. The carotenoid family is an example of these antioxidant compounds so that each type of carotenoid is responsible for a specific color. Chlorophyll in plants, which is responsible for the green color, is also an antioxidant, as are vitamins C and E. Some examples are represented in the following table:
Salads are an easy dish to prepare and can be a good strategy for introducing raw vegetables. Fruits can also be included. Dressing salads with healthy oils, vinegar, herbs or spices can increase the antioxidant capacity of the dish. Herbs are high in antioxidant and anti-inflammatory compounds. For example, several studies have shown that herbs and spices can lower blood pressure. You have to be creative and there is a lot of variety so you can always find dishes that suit the tastes of the youngest members of the household as well as the rest of the family.
A couple of simple dishes that can be prepared are:
2. Salads: This video shows 3 simple every salads
Fruits are one of the few natural products that are made to be eaten directly. In fact, this facilitates their reproduction as animals eat the fruit and disperse the seeds inside. The fruits have attractive colours and aromas. Fruits also soften on their own to a tender and juicy consistency. Fruits are therefore generally eaten raw, although they can also be cooked.
Unlike fruits, vegetables maintain a firmer consistency over time and taste too mild (like green beans or potato) or too strong (like onion or garlic). For this reason, vegetables mostly need to be cooked to make them tasty.
The following table shows the maximum loss of vitamins in foods during cooking.
|Vitamin||Maximum loss during cooking (%)|
Raw tomatoes are high in vitamin C. When they are green they contain a substance, tomatine, which is also in the leaves, which can help to reduce cholesterol. In many supermarkets tomatoes have been harvested when they are green and then the ripening process has been stimulated with ethylene gas, which is why these tomatoes are so tasteless when eaten. For this reason it is best to consume seasonal fruits and vegetables whenever possible.
Photo by Michael Burrows from PexelsFreezing is the most effective method of stopping the general metabolism of fruits and vegetables. However, most microbes are revived by heating the vegetable because they are resistant to freezing. Freezing that can be done at home can also spoil the texture and cause vitamins and pigments to be lost. If you are going to freeze vegetables or fruit for a long time it is best to first subject them to a blanching process. This consists of placing them in boiling water for 1-2 minutes and then transferring them to ice water to prevent further cooking and softening of the walls of the vegetable. In this way their texture, colour and properties are better preserved.
Source: PixabayNon-heat techniques are best suited to minimise nutrient loss, such as cured, marinated or pickled foods. It is important to wash raw vegetables thoroughly, but do not soak them because some of the vitamins and minerals will be lost in the water. You can also make homemade preserves at home. They are very useful to combine it later in different dishes. In these preserves ingredients are introduced to help preserve food for a longer period of time. One method is to use an acidic medium, such as vinegar, which destroys microorganisms and inhibits enzymatic growth. These methods are more like semi-preserves so cold or sterilization is necessary. Another technique for preserving in fat (confit) can be used for vegetables and also for meat and fish. They are usually sterilized as well.
Benefits of cooking vegetables
Question: Cooked vegetables have always lower nutrient availability compared to raw vegetables.
Question: The bioavailability of phenolic compounds is higher in raw tomatoes than in cooked tomatoes.
In many instances, cooking of food is necessary to make food safer and to facilitate digestion. Cooking always involves a chemical change in the food and food processing can have beneficial effects by increasing the bioavailability of antioxidant compounds. It is important to cook as gently as possible, trying to preserve the highest level of nutrients.
The following table shows which foods preserve their nutrients best when eaten raw and which foods preserve their nutrients best when cooked.
|Best raw||Best stew|
|Broccoli and watercress: Increased amount of an enzyme responsible for creating anticancer compounds||Carrots: Increased amount of carotenoids|
|Garlic: Increased amount of an enzyme needed to produce allicin, a healthful compound||Spinach: Better absorption of carotene and iron|
|Onions: Antioxidant compounds are better preserved||Cabbage: Increased amount of carotenoids|
|Peppers: Much higher amount of vitamin C||Tomatoes: Increased amount of lycopene|
Taken from Farrimond S. The science of cooking
Processing vegetables also changes the availability of some of their beneficial compounds. For example, crushing garlic instead of mincing it increases the production of allicin, which is one of the compounds that gives it health-giving properties. Similarly, it is better to finely chop onions. Similarly, chopping cruciferous vegetables, such as broccoli, increases the levels of isothiocyanates, which are bioactive products of glucosinolates.