**3. Bioactive compounds from vegetables and fruits by-product**

According to WHO (world health organization), a healthy diet consists of 5 servings of different fruits and vegetables or 400 g of them on a daily basis. People's diet varies in different countries, but in recent years many individuals consume more packaged food rather than fresh vegetables, which indicates the need for producing healthier food products. This can be achieved through producing bioactive compounds from vegetables and fruits by-products and adding them to conventional food [21].

Bioactive compounds are molecules that are produced in natural procedures, many of them are plant-based and can portray beneficial effects on human health. Commonly, fresh parts of fruits and vegetables are consumed, however, a huge part of phytochemicals exist in the seeds, shells, peels, bran, bagasse, and trimming, which are the by-products of the fruits and vegetables [22]. Tomato by-products (paste waste, skins, and seeds) can be used for the extraction of carotenoids, which regard as a lycopene source. Apple pomace contains phenolic compounds such as naringin and phlorizin. Phlorizin could be used in the synthesis of a new generation of antidiabetic drugs with the mechanism of inhibiting the sodium-glucose co-transporter 2.

*Bioactive Ingredients in Functional Foods: Current Status and Future Trends DOI: http://dx.doi.org/10.5772/intechopen.104416*

Grapes skins and other by-products including seed, stem, skin, and pomace are also rich in polyphenols namely resveratrol. White grape seeds could be used to extract gallic acid, catechin, and epicatechin [22]. Avocado's seed and peel are rich sources of carbohydrates, they also contain, lipids, proteins, fibers, and minerals. These byproducts contain terpenoids, alkaloids, saponins, and acetogenins [23].
