Generalized structure of Olestra Q Olestra is a sucrose polyester or SPE. Q SPEs are synthesized by reacting fatty acids with hydroxyl groups of sucrose in the presence of catalysts. Q Olestra is a common name for the mixture of sucrose esters formed from the addition of six, seven, or eight fatty acids to the available eight free hydroxyl groups of sucrose. Q Saturated and unsaturated fatty acids of chain length C12 to C20 and higher from various sources such as soybean, corn, palm, coconut, and cottonseed oil can be used to manufacture Olestra. Generalized structure of Olestra OR O RO RO RO OR OR O OR O OR Olestra The chemical configuration of Olestra accounts for its indigestibility and why it does not provide calories. Unlike normal fats that consists of one molecule of glycerol attached to three fatty-acid molecules, Olestra replaces the glycerol molecule with sucrose and has either six, seven, or eight fatty acids attached. With this many fatty acids, digestive enzymes cannot get to the sucrose center in the time it takes for the molecule to move through the digestive tract. The sucrose center is where breakdown of the substance for absorption into the body would take place. digestive OLESTRA enzyme fat+calories core REGULAR FAT with Olestra, so many fatty acid spokes are crowded around the core that the digestive enzymes the body's digestive enzymes break off the spokes cannot find a breaking point - so Olestra does not of fatty acid from their core, and the body absorbs release any fat or calories them.