Retrogradation

Retrogradation refers to the structural change in starch following processing, which has a direct impact on the quality and shelf life of the product.

Retrogradation is the time-dependent structural rearrangement of previously gelatinised starch. After gelatinisation, the dissolved starch molecules – particularly amylose and, later, amylopectin – reassemble into ordered, partially crystalline structures.

This process is often accompanied by firming, clouding or water separation and influences the texture, stability and shelf life of starchy products. Retrogradation occurs primarily during cooling and storage and is responsible, among other things, for bread becoming stale.

In process engineering, retrogradation is a key factor in the design of formulations, process conditions and mixing steps, particularly for starchy powders, premixes and instant products. The detailed blog post by amixon entitled ‘Starch Extraction and Starch Processing’ offers an in-depth insight. amixon^® processing machines also make significant contributions to the starch industry.