## 3 Bioactive Compounds in Fresh Fruits and Vegetables
### Changes in Food Caused by Cooking and Other Processing Treatments  
Food cooking is intrinsically linked to human evolution because it enabled the inclusion of a myriad of nutrients in our diet that are not available in raw foods. Food cooking enables starch gelatinization and protein and antinutrient denaturation that are essential to improve digestibility and nutrient bioavailability to our cells [68]. Moreover, cooked diets improve the energy yield by delivering more energy and reducing the energetic costs of detoxification and defense against pathogens [68]. However, specifically considering the bioactive composition of cooked foods, particularly those of vegetal origins such as grains, tubers, legumes, and fruits, cooking causes a thermal degradation, which may reduce the concentration of certain phytochemicals. However, the process also favors matrix softening, improving the extractability of many phytochemicals and so, depending on the bioactive compound and the matrix where it exists, a net increase in their levels in the final cooked product often occurs [69]. This yield can be further improved by adjusting the cooking procedure to the properties of the target bioactive compounds. Steaming, for instance, is a milder process than boiling because the plant tissues are not in direct contact with the boiling liquid, usually water. Therefore, fewer soluble bioactive compounds are leached, and thermal degradation is not so extensive as in the boiling procedure. Accordingly, steaming will enrich the cooked food with phenols and glucosinolates, for instance, while it is too mild to solubilize carotenoids that require more aggressive cooking procedures [69]. Another class of important bioactive compounds, polyamides, which are present in many foods of plant origin, including green peppers, peas, citrus fruit, and broad beans, are drastically reduced by more than 60% by boiling and grilling but remain almost unaffected by microwave and sous vide cooking [70]. Vacuum cooking is gaining popularity due to its ability to preserve or even enhance the sensory and health properties of different foods. Using pumpkin cubes as a model food, [PERSON], et al. [71] showed that vacuum cooking was more aggressive than sous vide or steaming, resulting in faster and deeper texture softening, but simultaneously less impact on pumpkin color despite the greatest extraction of some classes of carotenoids from the broken cells. In contrast, significant polyphenol extraction, especially of gallic acid and naringenin, was more efficient with sous vide and steaming pumpkins [71]. On this point, it is important to note that cooking can be used to add bioactive compounds to foods. To achieve this, very recently [PERSON], et al. [72] showed that French fries were enriched with virgin olive oil (VOO) bioactive compounds, namely sterols, upon deep-frying with VOO. Fermentation was one of the first processes humans used to prepare and preserve food for periods in which nutrient availability could be scarce [73]. It is estimated that fermented foods constitute about one-third of the foods consumed daily worldwide [74]. This includes fermented vegetable and fruit foods and beverages with high nutritional value and bioactive composition, as well as a large range of prebiotic compounds that can stimulate the growth of beneficial bacteria in the human gut [74]. Fermentation is so popular because the extraction of bioactive compounds from raw foods is accompanied by unique textures and flavors widely appreciated in diverse diets around the world. Wine, beer, and cider are popular beverages obtained from the alcoholic fermentation of fruits while lactic fermentation is more popular with vegetables. This is the case for sauerkraut (fermented raw cabbage), tempeh (traditional Indonesian fermented soybeans), natto and miso (traditional Japanese fermented soybeans), kombucha (fermented tea leaves), and kimchi (traditional Korean fermented vegetables).