From WikiPilipinas: The Hip 'n Free Philippine Encyclopedia
A dalandan or kahel is a variety of sweet orange (Citrus sinensis) that grows in the Philippines. Originally from China, the fruit is closely related to Valencia orange. The color of its skin can range from dark green to yellowish green. Like other kinds of citrus, it is reach in Vitamin C. It can be consumed fresh or by extracting its juice.
 Inside the fruit
The interior of a dalandan contains segments that are arranged in a circular manner, surrounding an axis that starts at the branch that connects it to the tree (or the stump that it left behind). Inside each of these segments are the seeds, juice and fleshy pulps.
To freshly consume the fruit, the skin is peeled off. Then, one segment is picked-out from the rest, bitten and its juice sipped. When seeds are the only ones left in that segment, it is disposed and another segment is picked-out to repeat the same process. This is repeated until all the segments are consumed.
To make a dalandan juice drink, slice it in half along the plane that is perpendicular to the axis of the segments. Slicing it this way will ensure that all segments are open and extracting their juice will be much easier. Then, squeeze each half above a glass or cup, add some water and sugar and then stir the mixture.