higheramylose

Higher amylose refers to starch in which the proportion of the glucose polymer amylose is greater than that found in typical cereal and tuber starches. While conventional starches commonly contain 25–28% amylose, high-amylose starches are defined as having 40% or more amylose, with some varieties reaching 70–85%.

High-amylose starch occurs naturally in certain plant varieties and can be increased through selective breeding, mutagenesis, or genetic modification of starch biosynthesis pathways. Commercial high-amylose starches are produced from maize, barley, rice, potato, and tapioca lines bred for elevated amylose content. Enzymatic treatment or processing can also modify amylose content in industrial applications.

Physicochemical properties of high-amylose starch differ from ordinary starches. The higher linear amylose fraction promotes stronger gel formation, higher pasting temperatures, and greater tendency to retrograde, which can lead to firmer textures but also blurred clarity in gels. A notable consequence is increased resistant starch formation upon digestion, contributing to a lower glycemic response and potential gut-health benefits.

Applications include food ingredients with altered texture and dietary fiber content, edible films, and biodegradable materials. In nutrition, higher amylose content is often marketed for its potential to raise dietary fiber intake and modulate glucose release, though effects depend on processing and food matrix.

See also: resistant starch, high-amylose starch.