CONICET | Buscador de Institutos y Recursos Humanos

Sorghum flour is an underused ingredient to develop gluten-free products such as pasta.The aim of present work was to study the nutritional attributes of pasta made from white(WSP) and brown (BSP) sorghum hybrids flours. Methodology used were: a) the starchhydrolysis during in vitro digestion by the glycemic index (eGI) estimation and b) a modifiedINFOGEST in vitro method which included a dialysis tube to asses bioaccesibility of starchand antioxidant activity. In both cases a non-linear fit to a first order kinetic model of starchhydrolysis to asses kinetic parameters of digestion. The eGI was ~64 for both samples, withno significant differences in kinetic constant (~0.014 min -1 ) and plateau-hydrolyzed starch of55.0 and 51.0 % for WSP and BSP, respectively. Bioaccessible starch values were similarfor both gluten free pasta samples (~35 g /100 g starch) and dialyzable starch was ~20g/100 g starch, with a starch hydrolysis extent of ~57 %. The kinetic constants were 0.172and 0.144 min -1 for gastric phase and 0.029 and 0.017 min -1 for intestinal phases in WSP andBSP, respectively. Polyphenols, reducing power and radical scavenging activity weredetermined in cooked pasta, been higher for pasta made from brown sorghum hydride. Inthis regard, antioxidant activity was measured inside (dialyzable) and outside (bioaccessible)the dialysis tube to assess in vitro antioxidant activity after digestion process. Duringdigestion, polyphenol content increased 2.9 (WSP) and 2.4 (BSP) times compared tocooked pasta and radical scavenging activity of BSP was higher than BSP in bioaccessiblefraction (980 mol trolox/100 g). It is important to note that the INFOGEST modified methodreached the same hydrolysis extent values than the eGI method. In conclusion, starchhydrolysis extent and rate were not affected by sorghum hybrids tested, and in vitroantioxidant activity was higher for brown sorghum flour pasta.