Modelling multiphasic starch digestograms: an objective procedure for slope discontinuities^†

Abstract

Objective procedure for slope discontinuities.

Homogeneities in in vitro starch digestion of compositionally heterogenous white wheat breads

“…Figure 2 summarises the application of the polynomial equations to the LOS-TLOS data of the breads. Using the Sopade Objective Procedure (Sopade, 2021), there were no slope changes or discontinuities in the starch digestograms because (objective logarithm of slope) the critical points from the derivative(s) of the higher order polynomial equation(s) were negative, did not leave four or more points in each segment, or were outside the digestion times (0-120 min). So, the heterogeneities in the breads essentially translated to homogeneities in the starch digestion patterns, and the null hypothesis is rejected.…”

“…Equations (1, 3, 5, 7, and 9) were simply computed with the Microsoft Excel Solver ® (GRG nonlinear method) by minimising the sum of squares of residuals (SUMSQ), constraining D 0 ≥ 0 g/100 g dry starch and D ∞ ≤ 100 g/100 g dry starch, and with no discarded data from 0-120 min (Sopade, 2021(Sopade, , 2022. Coefficient of determination (r 2 ), mean relative deviation modulus (MRDM), and plots of residuals were the predictability indices.…”

“…In using WWBs for eGIs, in vitro starch digestograms of the breads and non-bread samples are often modelled to obtain areas under the digestograms, from which hydrolysis indices (HIs = 100 × areas of the samples/area of the bread) are calculated to use in appropriate linear equations (Ferng et al, 2016;Mahajan et al, 2022;Sopade, 2022). Modelling starch digestograms is advancingly discarding subjectivities with practical conditions through equations that rely on sound statistics via predictability indices for robust interlaboratory comparisons (Sopade, 2021(Sopade, , 2022. The procedures, conditions, and equations apply to monoand multi-phasic starch digestograms for respective homogeneous and heterogeneous digestion patterns.…”

Enzyme kinetic approach for mechanistic insight and predictions of in vivo starch digestibility and the glycaemic index of foods

“…Recent developments in our understanding of amylolysis, however, emphasise the importance of basing estimations of RDS and SDS on sound data obtained from full digestibility curves rather than two time points of 20 and 120 min. A recent publication by Kim, Hong, Choi, and Moon (2021) supports the use of the RDS and SDS terminology and, like Sopade (2021 , 2022) , presents a modified form of LOS that considers simultaneous occurrence of rapid and slow digestion reactions with the rapid reaction predominating at the early stages. Compared with the original LOS method that assumes consecutive reactions ( Edwards et al, 2014 ), Yu and colleagues also report on the likely occurrence of rapid and slow reactions proceeding in parallel ( Yu, Zhou, & Li, 2021 ).…”

“…The importance and potential significance of amylase measurements has been emphasised in a recent publication that relates the value of in vitro screening of digestibility profiles of food products for prediction of likely glycaemic responses in vivo ( Edwards et al, 2019 ). It is becoming clear that a number of investigators have begun to adopt the LOS approach and introduce extensions that consider digestions that proceed at more than 1 or 2 distinct phases and hence allow improved predictions of likely GI outcomes ( Sopade, 2021 , 2022 ).…”