A mechanistic model to study the effect of the cell wall on starch digestion in intact cotyledon cells

Ana M Rovalino-Córdova,Victor Aguirre Montesdeoca,Edoardo Capuano

doi:10.1016/j.carbpol.2020.117351

Ana M Rovalino-Córdova, Victor Aguirre Montesdeoca + Show 1 more

Open Access

https://doi.org/10.1016/j.carbpol.2020.117351

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Journal: Carbohydrate Polymers	Publication Date: Nov 5, 2020
Citations: 14	License type: cc-by

Affiliation: Wageningen University & Research

Abstract

The role of the plant matrix is recognized as the main factor restricting starch digestibility in beans. Several authors have provided insights about the mechanisms behind the reduced starch digestibility in plant matrices. In this study, by means of a mathematical model, we provide a mechanistic explanation of the role played by the cell wall. It was confirmed that starch entrapped within intact cells could only be hydrolysed after α-amylase diffusion through the cell wall. This process is limited by the pores naturally present in the cell wall and the adsorption of α-amylase to the cell wall surface. These factors restrict the concentration of α-amylase available within the cells. The model assumptions are valid under controlled laboratory conditions and were validated with in-vitro digestion data giving very accurate results. The proposed approach provides new information to understand the digestibility of starch, and possibly other macronutrients, in complex food matrices.

Highlights

Starch is the primary carbohydrate produced by plants as energy storage and one of the main macronutrients in the human diet (Singh, Dartois, & Kaur, 2010)
We consider that the complex mechanism behind starch hydrolysis in Intact cotyledon cells (ICC) is due to the simultaneous action of several factors that will be discussed in detail
This study proposed a mechanistic approach designed to investigate the physical and kinetic factors involved in the reduced starch digestibility of beans

Summary

Introduction

Starch is the primary carbohydrate produced by plants as energy storage and one of the main macronutrients in the human diet (Singh, Dartois, & Kaur, 2010). A good example showing the importance of food structure in starch digestion are legumes, a food product with a relatively low glycaemic index. This has been confirmed by in-vitro studies, which indicate slow digestion kinetics of starch in beans (Berg, Singh, Hardacre, & Boland, 2012). Several publications confirm those results and demonstrate that the limited starch digestibility in beans is due to the restricted passage of α-amylase through the cell wall (CW) Even though this information provides insights about the mechanism behind the low glycaemic index of legumes, further research is needed to fully understand this effect

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