In vitro digestion of starches in a dynamic gastrointestinal model: an innovative study to optimize dietary management of patients with hepatic glycogen storage diseases

Uncooked cornstarch (UCCS) is a widely used treatment strategy for patients with hepatic glycogen storage disease (GSD). It has been observed that GSD-patients display different metabolic responses to different cornstarches. The objective was to characterize starch fractions and analyze the digestion of different starches in a dynamic gastrointestinal in vitro model. The following brands of UCCS were studied: Argo (R) and Great Value (R) from the United States of America; Brazilian Maizena Duryea (R) and Yoki (R) from Brazil; Dutch Maizena Duryea (R) from the Netherlands. Glycosade (R), a modified starch, and sweet polvilho, a Brazilian starch extracted from cassava, were also studied. The starch fractions were analyzed by glycemic TNO index method and digestion analyses were determined by the TIM-1 system, a dynamic, computer-controlled, in vitro gastrointestinal model, which simulates the stomach and small intestine. The final digested amounts were between 84 and 86 % for the UCCS and Glycosade (R), but was 75.5 % for sweet povilho. At 180 min of the experiment, an important time-point for GSD patients, the digested amount of the starches corresponded to 67.9-71.5 for the UCCS and Glycosade (R), while it was 55.5 % for sweet povilho. In an experiment with a mixture of sweet polvilho and Brazilian Maizena Duryea (R), a final digested amount of 78.4 % was found, while the value at 180 min was 61.7 %. Sweet polvilho seems to have a slower and extended release of glucose and looks like an interesting product to be further studied as it might lead to extended normoglycemia in GSD-patients.