Project Description

Starch pasting is the process by which starch granules uptake water in a heated aqueous medium and thicken a starch dispersion. This process is common in a variety of products (food, paper coating to the fabrication of paints) in order to produce a given texture. There is a lack of reliable, physics-based models to predict the rheology of starch suspensions that can be used to tailor processing conditions for a given texture. This would require understanding the swelling and breakup of starch granules, and its effect on the rheology of a suspension. The first part of the project will develop polymer swelling models to describe how different ingredient interactions alter starch granule size distribution during heating. This information will be combined with Stokesian dynamics simulation (below jamming limit) and foam rheology models (beyond jammed limit) to predict the viscoelasticity of the starch dispersion under a wide range of heating profiles, shear rates, and compositions. The second part of the project will visualize the rupture of starch granules during swelling via hot stage microscopy. Visualization of such granules will allow one to determine the mechanical modes of granule failure, which will allow one to develop statistical models for suspension rheology under breakup. This project, done under collaboration with industrial partners, will provide rational guidelines for industry to tailor the functionality of starch-based materials for a wide range of applications.

Start Date

Jan 2022

Postdoctoral Qualifications

The postdoctoral researcher should have a degree in Chemical Engineering, Mechanical Engineering, Materials Science, or equivalent. The research requires a strong background in fluid mechanics and rheology. Experience in computational fluid dynamics and colloidal/interfacial science is desirable.

Co-Advisors

1. Vivek Narsimhan, Assistant Professor of Chemical Engineering, vnarism@purdue.edu, https://engineering.purdue.edu/ChE/people/ptProfile?resource_id=169352

2. Ganesan Narsimhan, Professor of Agricultural and Biological Engineering, narsimha@purdue.edu, https://engineering.purdue.edu/ABE/people/ptProfile?resource_id=7368

Bibliography

1. J. Li, G.P. Desam, V. Narsimhan, and G. Narsimhan. "Methodology to predict the time-dependent storage modulus of starch suspensions during heating", Food Hydrocolloids, 113, 106463, (2021)

2. G.P. Desam, N.-L. Dehghani, G. Narsimhan, V. Narsimhan. "Characterization of storage modulus of starch suspensions during the initial stages of pasting using Stokesian dynamics simulations", Food Hydrocolloids, 121, 107010, (2021).

3. G.P. Desam, O. G. Jones, and G. Narsimhan. “Prediction of the effect of sucrose on equilibrium swelling of starch suspensions”. Journal of Food Engineering, 294, 110397, (2021)

4. G.P. Desam, J. S. Li, G. B. Chen, O. Campanella and G. Narsimhan (2018a). "A mechanistic model for swelling kinetics of waxy maize starch suspension." Journal of Food Engineering 222: 237-249.

5. G.P. Desam, J. S. Li, G. B. Chen, O. Campanella and G. Narsimhan (2018b). "Prediction of swelling behavior of crosslinked maize starch suspensions." Carbohydrate Polymers 199: 331-340.