The structure and function of resistant starch in glycaemia

Amylose-lipid complexes (ALCs, Figure 1), otherwise known as resistant starch 5 (RS5), are produced during food processing. During hydrothermal processing, starch begins to gelatinise, releasing amylose helices. Amylose can then complex with free fatty acids (FFAs) to form ALCs1, small aroma molecules to form amylose-aroma complexes, or form retrograded starch (RS3) if FFAs are absent. ALCs are resistant to digestion by alpha-amylase and are therefore classified as dietary fibre (DF). Studies have shown beneficial effects of increasing ALCs in food, seemingly reducing postprandial glycaemia after reheating, to a greater extent than RS3 alone2,3. ALC content can be increased by modifying food processing techniques or by reformulation. However, there are still no official methods and standards for reliably quantifying ALCs in foods