Starch is used in confections for gelling centers, coatings, dusting powder, and casting beds. To make jelly bean centers, starch is cooked with water, corn syrup, and sugar, and flavors are added. The mixture is then cast in trays of molding starch and dried in heated rooms. The candy is then coated and packaged.
Corn starch is used for cooking in kettles, with acid-thinned starch preferred for shorter texture and better gel strength. For jet or tubular cookers, high-amylose starches are used to gel faster and improve factory efficiency.
However, unmodified high-amylose starches require a higher cooking temperature of 170°C compared to thin-boiling starches that only need 140°C. Acid-thinned high-amylose starches and stabilized starches are also used.
Using high-amylose starches with more fluidity helps to speed up the gelling process and allows for higher amounts of solids. This has shortened the traditional drying time of thin-boiling starch gum drops from two days to just eight hours, leading to increased production. Monosubstitution is also used to improve shelf life and texture.
Hard gum candies like wine gums, lozenges, and chewy cough drops are usually made with tapioca dextrins to provide structure, stability, and clarity. Starch is added at a higher level, along with an equal amount of corn syrup and a lesser amount of sugar. Oxidized waxy maize starches are also used because they provide clarity.
Candy coatings are made by putting on several layers of dextrin and sugar solutions and then letting them dry. They use dextrins and modified starches because they make the coating look clear and appetizing, and they want it to be shiny and not crack. They sometimes use oxidized waxy maize starches. When making candy, they use dent corn starch with a little bit of mineral oil to make an impressionable bed so that the candy takes the right shape.