Amylose is a complex carbohydrate and one of the two main components of starch, the other being amylopectin.
It consists of long chains of glucose molecules connected bonds. Because these chains are straight, it is called a linear polysaccharide ("many sugars").
High amylose leads to firmer, less sticky products
Amylose affects the texture, gelatinization, and retrogradation of starchy foods. Higher amylose content in starch leads to firmer gels and less sticky textures.
For instance, high-amylose rice varieties, such as basmati, cook into firm, separate grains, whereas low-amylose varieties, called glutinous rice, result in a stickier texture. As cooked rice cools, the amylose in the grains begins to retrograde, causing the starch molecules to realign and crystallize. This process results in the rice becoming firmer and less sticky, with higher-amylose rice varieties exhibiting more pronounced hardness and separation of grains upon cooling compared to low-amylose varieties, which tend to remain softer and stickier.
For sauces and gravies, choosing starches high in amylose, such as cornstarch or high-amylose varieties of rice flour, results in a firm, stable gel that thickens effectively without becoming overly sticky. High-amylose starches create sauces that hold their structure well and remain clear, making them ideal for dishes where a glossy, consistent texture is desired.
In baked goods, the amylose content influences crumb structure and texture. Flour from high-amylose wheat varieties, or adding a portion of high-amylose flour like some types of whole wheat, can contribute to a denser, chewier texture in breads and pastries, which is desirable in products like rustic breads or pie crusts that benefit from a firmer, more defined structure. Conversely, low-amylose ingredients, like waxy corn starch, result in softer, more tender baked goods, making them suitable for products like cakes or pastries that require a delicate crumb.