Across samples, the extent of glucose recovered was less in vivo than in vitro (69 vs. 42% of starch). The rate of glucose release adjusted for plateau effects was lower in vivo (0.35 vs. 0.89%/min), whereas the shape parameter adjusted for plateau effects (sigmoidal modifier) was higher in vivo (37.9 vs. 13.7). Consequently, peak glucose release in vivo occurred 69 min postprandial, whereas it occurred only 6 min into the second stage of digestion in vitro.
Cumulative portal glucose appearance was strongly related (R2 = 0.89; P<0.001) to in vitro glucose release, although a nonlinear bias was observed. After correcting in vitro release with predicted gastric emptying, the relationship improved and became linear (R2 = 0.95; P<0.001).
It is concluded that, in vitro starch digestion kinetics predict portal glucose appearance up to 8 h postprandial accurately provided that in vitro data are corrected for gastric emptying.
TATG van Kempen, PR Regmi, JJ Matte, and RT Zijlstra, 2010. Journal of Nutrition, 140: 1227–1233.