The Different Varieties of Rice
Amylase is a long type of starch, a straight starch molecule that does not gelatinize during cooking, so the rice variety which contains more of this starch tends to cook fluffy, with separate grains. Long grain white rice has the most amylase and the least amyl pectin, so it tends to be the fluffiest and least sticky.
Amylase also hardens more when cool, joining tightly together and forming crystals that melt when the rice is reheated. Rice that is high in amylase has a lower glycemic level.
Amyl pectin is a highly branched molecule that makes the rice sticky when it’s released from the grain during cooking. Medium grain rice has more amyl pectin, making it a good candidate for rice pudding, risottos, and salads, which are served cold.
Short grain rice has even more amyl pectin and little to no amylase, so it’s used most often for sticky rice, used primarily in Asian cooking when you want the rice grains to be sticky so they are easier to eat with chopsticks.
Then you have the last type which is the glutinous rice, which is a very sticky variety when cooked, with the highest amount of amyl pectin and no amylase content at all.