Impact of physical and enzymatic cell wall opening on the release of pre-gelatinized starch and viscosity forming potential of potato flakes.

Potato flakes (PFs) are used in instant foods. They contain pre-gelatinized starch which readily develops viscosity upon hydration. We here provide the first report on factors influencing their viscosifying potential. Swelling power (SP) (r = 0.719, p < 0.01) and mean particle size (r = -0.704, p < 0.05) mainly determine instant viscosity development of PF suspensions while short extractable extracellular amylose molecules [degree of polymerization between 150 and 1500 (EE-AM150-1500)] positively impact their cold paste viscosity (CPV) (r = 0.717, p < 0.01) in Rapid Visco Analyzer (RVA) models. Cell wall opening by ball milling or cellulase treatments increased PF SP resulting in up to 75% higher RVA peak viscosity readings. Furthermore, the release of EE-AM150-1500 molecules increased CPV by about 30% since they readily associated upon cooling. Partial cell wall opening thus improves the viscosifying potential of PFs and expands their applicability in instant foods.