Quantitative characterization of the digestive viscosity profile of cereal soluble dietary fibers using in vitro digestion in Rapid ViscoAnalyzer

Abstract A standard method measuring viscosity ( η ) of cereal products through in vitro digestion in a Rapid ViscoAnalyzer has been developed previously and is predictive of some physiological effects of cereal foods. This paper proposes a simple mathematical model to analyze quantitatively the digestograms obtained by that method. Digestograms of twelve uncooked and cooked cereal products were generated and data quality was assessed. Experimental data were fitted with a viscosity model η m o d e l = η 1 + η 2 , where η 1 = A e - k 1 t and η 2 = B - C e - k 2 t were respectively viscosity decrease and viscosity increase components. The model showed very good agreement with experimental data and enabled interpretation of the digestograms in relation to the composition of the products: η 1 was interpreted as the decreasing viscosity of digestible polymeric nutrients whereas η 2 was interpreted as the viscosity development of viscous dietary fibers. This model may be useful to investigate quantitatively the biological effects of soluble dietary fibers in cereal products and similar products.