Flavonoids

Flavonoids are secondary metabolites found in fruit, vegetables, grains, beverages (tea and wine), and also in food by-products. Food by-products have been recognised as significant sources of flavonoids that have been undervalued. Several studies identified that by-products flavonoids content is frequently higher than in the raw source material. Flavonoids stand out by their diversity in chemical structure, activities, and potential application in industry. Flavonoids have been reported as antioxidant, antibacterial, antiviral, anti-inflammatory, antihypertensive, and antihyperglycemic agents in few clinical trials but in several in vitro and in vivo tests. The cardioprotective and antidiabetic activities of flavonoids are well-documented, being valuable beneficial effects in disease prevention and treatment with applicability in the pharmaceutical and nutraceutical industry. Antioxidant and antimicrobial activity of flavonoids were also applied in food preservation, and the food industry has also been exploring flavonoids as potential natural colouring agents. Cosmetic is another industry where flavonoids have been gaining importance due to their antioxidant, anti-inflammatory, and antimicrobial activity, but also to their UV-protecting and even wound healing properties.