Vegetables are tasty, good for you, and we should eat plenty of them, varying our choices as much as possible — everyone knows that. But if we don't handle them properly in the kitchen, we can say goodbye to their nutrients, colours and beneficial properties. Here are the seven things you need to know.
If the crunchier green vegetables — such as broccoli, green beans or asparagus — are boiled, there is a risk of making them dull, dark and washed out. This happens because chlorophyll, the pigment that gives vegetables their green colour, undergoes a chemical transformation when exposed to heat and takes on a shade tending towards grey or yellow. An acidic environment encourages this transformation: it is the acids contained in the vegetables themselves that, as they are released into the cooking water, trigger it. One of the home remedies often recommended to solve the problem is adding bicarbonate of soda to the cooking water: in terms of preserving the vegetables' bright colour, the method works because bicarbonate of soda, being alkaline, counteracts the acidity of the water; however, from a nutritional standpoint, adding bicarbonate of soda promotes the loss of vitamins and minerals. Fortunately, there is a way to cook vegetables without letting them lose their colour while preserving their flavour and nutrients. Simply follow these straightforward rules: place a large pot of unsalted water on the heat; once the water reaches a full boil, add the vegetables, which should have enough room to float freely in the water (avoid adding too many vegetables to too little water); cook over a very high heat with the lid off; drain the vegetables when they are still very much al dente and immediately run them under cold water. The method works because the large amount of water dilutes the acids contained in the vegetables, reducing their effect; in addition, some of the acids evaporate when the lid is left off; finally, chlorophyll is more easily altered between 65 and 75°C, so it is important to avoid the vegetables lowering the water temperature for a prolonged period — which is what happens when too many vegetables are boiled in too little water. Cooling under cold running water also helps, as it halts the transformation of the chlorophyll and fixes the green colour. Despite involving boiling, this type of cooking, provided it is brief, does not compromise the nutritional content of the vegetables.
The vitamins found in fresh vegetables and fruit are at risk of being lost if we do not know how to handle them properly. Light, heat and cold can all easily destroy vitamins. It is important to avoid leaving vegetables to soak in water for a long time, and above all not to cut them before washing — leave them whole instead. Cut them only afterwards, and eat them straight away. If cooking is needed, it is best to keep it brief, bearing in mind that according to recent studies even boiling, if done quickly, is not as damaging to vitamins and minerals as once thought.
As everyone now knows, eating vegetables every day and in abundance is one of the cornerstones of a healthy diet. Vegetables, first and foremost, are anti-cancer because they provide fibre. To stay healthy, we would need to eat at least 30 grams of fibre every day, yet on average we consume only 15 grams. According to statistics, people who eat a lot of fibre significantly reduce their risk of developing bowel cancer. Vegetables are rich in it — worth remembering. Vegetables and fruit also act as a shield against high blood pressure: among the most beneficial are broccoli, carrots, pumpkin, cabbage, spinach, asparagus, pears, apples, melon, plums, apricots and bananas, as they are sources of potassium while containing very little sodium. The protection offered by calcium and magnesium is found primarily in legumes and green leafy vegetables. Natural antioxidants: vegetables are exceptionally rich in them. For this reason, they should never be absent from the table of anyone who wants to keep their body and mind young and healthy.
Fruit and vegetables help the body to naturally expel toxins — substances that accumulate beneath the skin, reducing its elasticity and restricting blood flow in the capillaries, and that lead to water retention and the formation of cellulite. In particular, the foods with anti-cellulite properties include spinach, aubergine, celery, carrots, watermelon and onions. Spinach has a high content of potassium, phosphorus, calcium and other minerals. It stimulates circulation and, thanks to its fibre, detoxifies the intestine, while also being a powerful antioxidant. Aubergine, rich in water, counteracts water retention and, thanks to its mineral salt content — potassium being the most notable — has an anti-cellulite effect. The same can be said of celery, which is also composed mainly of water and rich in potassium, a mineral that counteracts the action of sodium and therefore water retention. Finally, cooked carrots, endowed with antioxidants that act as a barrier against pollutants, contain vitamin C, vitamin B, docarine and beta-carotene. Docarine may be useful in the fight against cellulite as it has a beneficial effect on blood circulation and on the body's system for eliminating excess fluids. Watermelon, the fruit of summer, also combats cellulite by reactivating microcirculation and supporting kidney function. Extremely rich in water (92 per cent) and very low in sugars (8 per cent), it is the ideal fruit for staying hydrated without retaining fluids. Watermelon juice in particular is useful for those who suffer from swollen legs. Onions, finally, have an effective diuretic action: they facilitate the elimination of fluids that have accumulated in the tissues, thus counteracting the formation of cellulite.
Why is it important to choose seasonal vegetables? Vegetables grown out of season come from greenhouses, where they undergo numerous treatments with synthetic chemical products that stimulate their growth and protect them from attack by pests and disease. These plants are indeed more fragile than those grown in the field, precisely because they grow in an unsuitable season — one different from their natural one. This type of cultivation produces vegetables that disappoint in terms of both flavour and nutritional value: these are vegetables that have not had the time or the energy to synthesise, during their growth, many of the nutritional compounds they possess when grown in the right season. Furthermore, greenhouse cultivation requires a large amount of energy. Vegetables grown in their natural growing season are therefore more flavourful, richer in nutrients and beneficial active compounds, and have a lower environmental impact.
"If there is nothing more fascinating than discovering the world's biodiversity, knowing it and embracing it (even in our diets), we must become ever more aware in our everyday behaviour. Because a food, when it is in season and local, when it has travelled only a short distance to reach our tables, is not only tastier but also decidedly healthier, because it has been harvested at a riper stage, because it has not been subjected to stress, because it has not been stored for a long time in a fridge or a warehouse. We will then discover that superfoods are also right on our doorstep and that perhaps, as well as doing us more good, they also benefit the economy of the communities in which we live," writes Carlo Petrini in La Stampa.
Antioxidants are substances that protect the body from the harmful action of free radicals, which are responsible for cardiovascular disease, cancer and ageing. Vegetables already contain them in considerable quantities, but scientists at the Institute of Biological Chemistry at the University of Urbino have discovered that adding even just a few grams of herbs and spices to vegetables significantly increases the antioxidant capacity of our dish. To give a few examples, 3 g of marjoram added to 200 g of mixed salad increases its antioxidant content by 200 per cent! Among the spices tested by the researchers, those most synergistic with the antioxidants in vegetables are cumin and fresh ginger.
Chlorophyll is the pigment that gives plants their green colour. It is thanks to its presence that vitamins are synthesised and that we can perceive the sense of freshness in green vegetables when we taste them. Chlorophyll has numerous health-giving properties: it is anti-anaemic, purifies the blood, tones the heart, regulates cholesterol levels, promotes wound healing, disinfects and deodorises the skin, neutralises toxins and rebuilds tissues. It is abundant in all green leafy vegetables, in particular spinach, broccoli, chard and Swiss chard, Tuscan kale, chicory, catalogna chicory, dandelion and agretti, and spirulina algae.