Paper Number
SC47 

Session
Suspensions and Colloids

Title
Flow and alignment of protein nanofibril suspensions

Presentation Date and Time
October 12, 2022 (Wednesday) 2:50

Track / Room
Track 1 / Sheraton 4

Authors (Click on name to view author profile)

  1. Santos, Tatiana P. (Okinawa Institute of Science and Technology)
  2. Calabrese, Vincenzo (Okinawa Institute of Science and Technology)
  3. Boehm, Michael W. (Motif FoodWorks, Inc.)
  4. Baier, Stefan K. (Motif FoodWorks, Inc.)
    Baier, Stefan K. (The University of Queensland School of Chemical Engineering)
  5. Shen, Amy Q. (Okinawa Institute of Science and Technology)

Author and Affiliation Lines (in printed abstract book)
Tatiana P. Santos1, Vincenzo Calabrese1, Michael W. Boehm2, Stefan K. Baier2,3 and Amy Q. Shen1
1Okinawa Institute of Science and Technology, Okinawa, Japan; 2Motif FoodWorks, Inc., Boston, MA; 3The University of Queensland School of Chemical Engineering, St. Lucia, Queensland, Australia

Speaker / Presenter 
Santos, Tatiana P.

Keywords
experimental methods; bio-fluids; biomaterials; colloids; flow-induced instabilities; suspensions

Text of Abstract
Protein nanofibrils (PNFs) obtained through the self-assembly of milk whey proteins or peptides have gained increased attention in food and material science-related applications since they serve as good rheological and texture modifiers, as well as gelling and stabilizing agents. Although the physical and technological properties of such a prominent colloidal material have been recently investigated (e.g., effect of physico-chemical conditions, stabilization of emulsions, formation of gels, etc.), the flow-induced modification of the PNFs in the isotropic state has not been systematically explored yet. In this work, a simple shear-dominated microfluidic platform is employed to assess the effect of flow (i.e., onset and pattern of alignment and velocity profile) on β-lactoglobulin PNFs with different flexibilities. In particular, we used a combination of flow-induced birefringence (FIB), μ-particle image velocimetry (μ-PIV), and conventional rheological characterization techniques, to understand the onset of flow-induced alignment of β-lactoglobulin PNFs. A universal curve involving the Péclet number (Pe, a dimensionless number quantifying the relative strength between the shear rate and the rotational diffusion coefficient of the nanofibrils) and an alignment parameter (birefringence signal Δn normalized by the mass fraction of protein φ), could be established from our systematic experimental results to predict the alignment and flow profile of PNFs under shear-dominated flow (in the range of 1 < Pe < 105 and 10-4 < Δn/φ < 3x10-3). Our results shed insights on the physical-mechanical fate of PNFs under various manufacturing operations, e.g., processes of PNFs in the scale-up food industry as well as when passing through gastrointestinal digestive systems.