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 all applications that use starches (e.g., foods and pharmaceuticals), yet there is a lack of physics-based models that predict how granule swelling and breakup is affected by starch chemistry, heating conditions, and additives (e.g., sugars, gums, fats). The first part of the project will combine granule swelling experiments with polymer swelling (i.e., Flory) theories to understand how starch chemistry and food additives alter the granule size distribution during heating. The second part of the project will visualize the rupture of starch granules via hot stage microscopy. This information will determine the mechanical modes of granule failure and allow one to develop statistical models for breakup. The last part of the study will develop paste rheology theories to relate the flow behavior of the starch dispersion to the particle size distribution from the swelling and breakup theories. 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 and processing conditions.

Start Date:

Jan 2023

Postdoc Qualifications:

The postdoctoral researcher should have a degree in Chemical Engineering, Mechanical Engineering, Agricultural and Biological Engineering, Food Science, or equivalent. The research requires a background in colloidal science and rheology.

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

Outside Collaborators:

1. John Frostad, Assistant Professor of Chemical and Biological Engineering, University of British Columbia
2. Guibing Chen, Associate Professor, North Carolina A+T State University

Bibliography:

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)

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).

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)

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.

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.