Sandoricum koetjape, commonly known as the santol, sentul, or cotton fruit, is a tropical fruit tree in the family Meliaceae. Native to the Southeast Asian peninsula and the Malay Archipelago, it has been widely naturalized throughout tropical regions, including India, the Caribbean, and Mauritius. The genus name Sandoricum is derived from the vernacular Malay name sentul, while the species epithet koetjape is from kecapi, an Indonesian regional name for the fruit. Historically, the tree has been a vital component of traditional village agroforestry systems, providing both edible fruit and durable timber, and it remains a cherished cultural symbol in many parts of Southeast Asia, where its harvest signifies the transition between the dry and wet seasons.

The tree is a robust, fast-growing evergreen that can reach heights of up to 30 meters. It features large, trifoliate leaves with glossy, dark green leaflets and small, yellowish-green flowers arranged in terminal panicles. The fruit is a globose or flattened berry, varying significantly in size and thickness depending on the variety—typically categorized into "yellow" types, which have a thin, sweet rind, and "red" types, which possess a thicker, more acidic, and often more aromatic rind. The interior of the fruit contains soft, juicy, white pulp that clings to several large, inedible seeds. Sandoricum koetjape thrives in hot, humid lowland tropical climates and is highly adaptable, often found in backyard orchards or along forest boundaries.

The santol offers a dual-use culinary profile based on its variety and ripeness. The pulp surrounding the seeds is generally sweet and juicy, often eaten fresh with a sprinkle of salt or chili. The thick, edible rind of the fruit is a distinctive regional delicacy; in the Philippines and Thailand, it is frequently used in traditional sour-savory dishes like sinigang or grated into salads like som tum to provide a refreshing acidity. It can also be preserved by boiling in sugar syrup or candy-making, which softens the rind’s tough texture and mellows its naturally astringent flavor. Its unique combination of sweet-and-sour notes makes it a versatile ingredient for both snack foods and complex curries.

Nutritionally, the santol is a good source of dietary fiber, Vitamin C, and essential minerals such as calcium and iron. Its biochemical matrix is rich in specialized secondary metabolites, most notably limonoids and triterpenoids, which contribute to the fruit's characteristic bitter-astringent undertones. These compounds are of significant interest in pharmacognosy for their potential anti-inflammatory, antimicrobial, and anti-cancer activities. Traditionally, the bark and leaves of the tree have been utilized in folk medicine as a tonic for post-partum recovery and to treat fevers or intestinal inflammation, owing to the presence of these potent bioactive constituents.