Multi-response modeling of reaction-diffusion to explain alpha-galactoside behavior during the soaking-cooking process in cowpea

- A model describes α-galactoside behavior during cowpea soaking-cooking process.
- No thermal degradation of α-galactosides was observed even at boiling temperature.
- Overall, adjusted α-galactoside apparent diffusivities increased with temperature.
- At 30 °C and 60 °C, rate constants were identified in the seeds and soaking water.
- This approach can be used to identify scenarios that minimize α-galactoside content.

A modelling approach was developed to better understand the behavior of the flatulence-causing oligosaccharides in cowpea seeds during isothermal water soaking-cooking process. Concentrations of verbascose, stachyose and raffinose were measured both in the seed and in the soaking water during the process (T = 30, 60 and 95 °C). A reaction-diffusion model was built for the three considered alpha-galactosides both in the seed and in the soaking water, together with a model of water transport in the seed. The model reproduced coupled reaction-diffusion of alpha-galactosides during the soaking-cooking process with a good fit. Produced, diffused and degraded alpha-galactoside fractions were identified by performing a mass balance. During soaking at 30 °C, degradation predominated (maximum found for raffinose degradation rate constant of 3.22 × 10−4 s−1) whereas diffusion predominated at higher temperatures (95 °C).