Nutritional Benefits of Citrus Fruits

Citrus is an evergreen shrub or small trees belonging to the family of Rutaceae, grown in tropical, sub-tropical and temperate regions, citrus including oranges, Mandarins, Tangerines, Limes, Grapefruits, Lemons, and Citrons, as well as many hybrids and varieties [1]. Fruits reach to maturity stage between mid-December and April in the Northern Hemisphere particularly oranges and grapefruit, also, the fruit available around the year approximately.


Botanical of Citrus
Citrus is a genus from family Rutaceae which containing 130 genera with several important varieties, Citrus is an evergreen aromatic shrub or small trees native to South-East Asia, but now cultivated in subtropical and temperate region all over the world; Around 70% of the world's total citrus production is grown in the Northern Hemisphere, in particular, Mediterranean region and the United States, although Brazil and South Africa in Southern Hemisphere. Global citrus production reaches to 124.25 million ton in 2016 China ranking as the biggest producer of citrus followed by Brazil These citrus fruits are the precious resource of phytochemicals which are beneficial for the human body as vital bioactive medicines, Phytochemicals are naturally present in citrus juices and play a role in physiological functions and metabolic change of human body [4], also, Citrus fruits and juice has a unique value of essential nutrients, and these nutrients protect against several chronic diseases [5]. Citrus has potential health benefits like antimicrobial, antiinflammatory, antiviral and anticancer, besides that, Citrus juice contains a lower amount of cholesterol that helps for diabetes patients [6].

Chemical composition of Citrus Fruits
There are valuable natural chemicals in citrus fruits, it is an excellent source of different elements and vitamins required for the human body, including C vitamins, B vitamins, potassium, phosphorous, and other elements ( Table 1).

Phytochemicals in citrus fruits
Citrus phytochemicals distribution in various parts of fruits, phytochemicals exhibit the antibacterial, antiviral, antifungal, anticarcinogenic, antithrombotic or anti-inflammatory properties, also, it assists in lowering cholesterol. These active compounds are phenols, carotenoids, phytoestrogen and sulfides having antioxidative potential, and marked as health promoter due to their broad spectrum in the human body [8].
Flavonoids: Citrus fruit is a rich resource of flavonoids with many physiological properties involved in controlling antiviral activity and anti-microbial activity. They are present in the form of the glycoside or aglycone, especially in citrus juices as glycosyl derivatives (flavonoid glycosides, FGs) which showed potential health benefits for the human body [9]. It had excellent potential to control many chronic diseases and suppressed the infectious in the body. Hesperidin and quercetin involve in control of herpes virus, parainfluenza and polioviruses [10]. The naringin metabolites are a rich source of natural antimicrobials activity against the positive and negative bacteria [11]. Mandarin fruit has the highest content of flavonoids, followed by common oranges and Grapefruit, however, there is no any flavonoids in lemon fruit.

Tannins:
The grapefruit, lemon, and lime fruits have a higher content of tannins compounds than other citrus fruits, this tannins play an important role in stop diarrhea and decrease bleeding and controls other extreme secretions of the body [14].

Some health benefits of citrus
Citrus fruits have a wide range of biological activity for maintaining body health (Table 3). Also, Sweet orange and lemon fruits have a vast range of bioactive compounds which reported a 60-70% control of liver diseases [7]. However, Citrus juice particularly grapefruit juice contains enzymes particularly P-45 enzyme which considered a natural tool for obesity control and contained a range of different protein which burns human fats [13].
The lemon fruits have numerous bioactive compounds, and the juice of lemon possesses more than 200 compounds which involve regulators of the human body [4]. However, lemon and sweet orange juices have a wide range of bioactive compounds controlled about 60-70% of liver diseases through control lipids.