Molecular Dynamics Simulation of Starch Gelatinisation in Nigerian Food Processing: Engineering Implications for Reactor Design

This study applies molecular dynamics simulation to characterise starch gelatinisation behaviour in major Nigerian starchy food crops including cassava, yam, and maize, deriving engineering implications for the design of thermal processing reactors used in Nigerian food processing industries. Starch gelatinisation is a fundamental phase transition that determines the functional properties of starchy food products including garri, pounded yam, and maize-based porridges. The molecular mechanisms of gelatinisation and their dependence on starch molecular architecture, temperature, water content, and shear conditions are relevant to the design of efficient mixing, heating, and processing equipment. This study combines molecular dynamics simulation using GROMACS software with experimental validation through differential scanning calorimetry, small angle X-ray scattering, and rheological measurement. Amylose-amylopectin ratio, chain length distribution, and crystallinity characterisation is conducted for cassava TMS 30572, white yam Dioscorea rotundata, and TZPB maize varieties. MD simulations model water penetration, hydrogen bond disruption, and chain disentanglement during gelatinisation at processing-relevant temperatures and shear rates. Engineering parameters including viscosity functions, energy requirements, and mixing time are derived from simulation outputs and validated experimentally. Findings reveal molecular-level differences between Nigerian starch varieties that translate into significant differences in gelatinisation temperature range, peak viscosity, and process energy requirements. The MD-derived engineering parameters are integrated into reactor design calculations for improved processing equipment specification. The study recommends MD-derived processing parameters in Nigerian food engineering curriculum and industry practice.

Keywords: molecular dynamics simulation, starch gelatinisation, food processing, reactor design, Nigeria.