The health-promoting substances found in citrus fruits have been isolated in over 30 types, the main ones being: flavonoids, monoterpenes, coumarins, carotenoids, phenylpropanoids, acridones, and glycosylglycerolipids.
Flavonoids
The flavonoids in citrus fruits fall into three types: Type I, represented by rutin, are common flavonoids; Type II are flavanones unique to citrus, such as hesperidin and naringin; and Type III are special polymethoxylated flavonoids found only in citrus, such as tangeretin, which have not been discovered in other vegetables or fruits. Carotenoids
As is well known, many vegetables and fruits contain carotenoids, substances that play a significant role in human health. Research on the physiological functions and mechanisms of carotenoids has developed rapidly in recent years. In China, these substances have also been used to develop some health foods that are now produced industrially. Coumarins
The coumarins found in citrus are substances that have been fully affirmed by scientists as having anti-cancer properties. Research indicates that the anti-cancer function of coumarins is mainly achieved through two pathways: one is that coumarins detoxify carcinogens through the action of detoxifying enzymes; the other is that they antagonize and inhibit the activation of carcinogen metabolism. These two effects mainly produce inhibitory results during the initial stage of cancer. Monoterpenes, Triterpenes
Citrus fruits contain a large amount of terpenoid compounds, represented by (R)-limonene. Terpenes are the substances that constitute the unique aroma of citrus and have a sedative effect on the human central nervous system. Recent research has also confirmed that they have a stress-reducing effect and can help eliminate fatigue. Limonin
Limonin is the bitter component in citrus fruit juices, with a content of about 100-200 ppm in citrus fruits. However, recent research has found that limonin also has a tumor-inhibiting function. Other Chemical Components
This refers to three compounds found in citrus: phenylpropanoids, acridones, and glycosylglycerolipids.
The entire orange can be considered a treasure, as its pulp, peel, seeds, and inner membranes can all be used as medicine. The dried outer peel of the orange is called "Chen Pi" (meaning "aged peel"), because it is known to have better medicinal properties when aged. The white, web-like strands on the orange pulp are called "orange threads" (Jie Luo), which contain a certain amount of vitamin P and are said to have effects such as promoting circulation, resolving phlegm, regulating qi, and relieving stagnation. The orange seeds are bitter and non-toxic in nature, and have the effect of regulating qi to relieve pain, and can be used to treat conditions like hernia and back pain. Even the orange roots and leaves can be used as medicine, possessing different functions such as soothing the liver, strengthening the spleen, and harmonizing the stomach.
The pulp of the orange is sweet and delicious, and there are countless food therapy recipes using it. For example, when dry mouth and lips are caused by the depletion of bodily fluids, drinking more orange juice can replenish fluids and increase nutrition. Additionally, oranges can also be used to treat conditions such as stomach cold and vomiting, qi stagnation and food accumulation, and indigestion.