**9. Conclusion**

*Citrus* contains a variety of secondary metabolites, including phenolic acids, alkaloids, coumarins, flavonoids, carotenoids, limonoids, and volatile chemicals, which give a rational foundation for a variety of biological functions. Flavonoids, particularly methoxylated, flavones and flavanonols, and flavanones have greater bioactivities than other secondary metabolites. All of these active forms, however, operate together to give antimicrobial, antioxidative, anti-cancer, anti-inflammatory, hepatoprotection, neuroprotection, cardiac protection, and other advantages. *Citrus* are beneficial fruits to eat daily because of having multiple active forms with varied biological properties, both for their nutritive value and as chemotherapeutic or additional medication to promote health. *Citrus* fruit has various applications in the food industry. It can be used in the production of various food products. The bioactive compound, which is extracted from *Citrus* may be used in food additives, as stabilizers, thickeners, emulsifiers, preservatives, food colorants, and for many other purposes.
