The stringy, spongy white material often discarded when peeling an orange is a concentrated source of beneficial plant compounds. This part of the fruit is packed with dietary fiber and potent bioflavonoids, making it a valuable addition to your diet. Incorporating the white pith alongside the juicy segments offers significant health advantages. These components support various bodily functions, ranging from digestive regularity to cardiovascular health.
What Exactly Is the White Part of an Orange?
The technical name for the white part of the orange is the albedo, which is the inner layer of the fruit’s rind. It is also commonly referred to as the pith, and anatomically, it is classified as the mesocarp. This porous, pale tissue is located directly beneath the colorful outer skin, known as the flavedo or zest. The albedo surrounds the edible, juicy segments.
Its structure consists primarily of cellulose, hemicellulose, and pectin, giving it a slightly chewy, sometimes spongy texture. While it is often removed due to a perception of bitterness, the albedo of sweet oranges is generally tasteless or only mildly bitter. This is unlike the pith of grapefruit or lemon. This physical structure serves as a protective layer and a water reservoir for the fruit.
The Powerhouse of Fiber and Bioflavonoids
The albedo is distinguished by its high concentration of dietary fiber, which is its main component by weight. The insoluble fraction is present in a much higher proportion than the soluble fraction, such as pectin. Insoluble fibers, including cellulose and hemicelluloses, provide bulk. Soluble fibers form a gel-like substance when mixed with water.
Beyond fiber, the pith is a significant repository of citrus bioflavonoids, particularly a compound called hesperidin. Hesperidin is an antioxidant found in high concentrations in the albedo and the peel, often more concentrated here than in the fruit’s juice. Other beneficial compounds, such as the flavonoid naringenin, are also present. These potent plant compounds contribute to the overall antioxidant capacity of the white pith.
Actionable Health Benefits for the Body
The high level of soluble and insoluble fiber present in the albedo offers substantial support for digestive health. Insoluble fiber increases stool bulk and promotes regular bowel movements, aiding in the prevention of constipation. Soluble fiber, specifically the pectin content, acts as a prebiotic. This prebiotic feeds beneficial bacteria in the gut microbiome.
The powerful bioflavonoids, including hesperidin, provide numerous cardiovascular benefits. Hesperidin helps blood vessels function more effectively by improving blood flow and maintaining the integrity of the vessel walls. Studies suggest that consuming the hesperidin-rich pith may also help reduce serum triglyceride levels. It can also potentially lower LDL (“bad”) cholesterol.
The soluble fiber content also plays a role in regulating blood sugar levels. By forming a viscous gel in the digestive tract, this fiber slows the rate at which carbohydrates are absorbed into the bloodstream. This slower absorption helps prevent the rapid spikes in blood sugar that can occur after a meal. The antioxidant activity of the bioflavonoids works to neutralize harmful free radicals, reducing overall oxidative stress and inflammation.