Abstract #T90

# T90
Edible electrospun nanofibers from caseinate and pullulan blends.
S. Akkurt*1,2, K. L. Yam1, L. Liu2, R. Kwoczak2, P. M. Tomasula2, 1Food Science Department, Rutgers University, New Brunswick, NJ, 2Dairy & Functional Foods Research Unit Department of Agriculture, Agricultural Research Unit Service, Eastern Regional Research Center, Wyndmoor, PA.

Electrospinning is a technique that applies an external voltage to a polymer solution to produce micro- or nano-scale fibers. This technique has been used to electrospin synthetic polymers from organic solvents and more recently to create edible fibers from aqueous calcium (CaCAS) or sodium caseinate (NaCAS) solutions. Previous studies showed that electrospinning of pure CaCAS or NaCAS from aqueous solutions was not possible. To overcome this challenge, pullulan (PUL), which creates homogeneous nanofibers, was used as a spinning aid. The objective of this study was to examine the effect of PUL addition on the entanglement of PUL and CAS molecular chains, compared with the pure CAS and PUL solutions, and on the morphology and size of the resultant electrospun nanofibers. Stock solutions of 15 wt% CaCAS, NaCAS, and PUL (controls) were prepared separately, and stirred for 2h at 20°C. Blends of the CAS and PUL solutions were prepared in a 1:1 weight ratio at various concentrations. 3mL of each solution was then loaded into a syringe to feed a nanofiber electrospinning unit at flow rate of 1mL/h, and at 11 or 20kV, respectively. Each run was observed for fiber deposition on the rotating drum. Electrospraying was observed for pure PUL, CaCAS or NaCAS solutions at concentrations below 6.0, 9.0, or 7.0 wt% because the low solution viscosities did not promote molecular entanglement. Fibers were observed for CaCAS: and NaCAS:PUL above 9.0 and 9.5wt% showing entanglement with the added PUL. Fiber sizes were determined using ImageJ software to sample the fibers and calculate mean diameters from scanning electron microscopy images. More uniform fibers were observed at 11kV than at 20kV for the PUL and NaCAS:PUL solutions, but CaCAS:PUL fibers were of similar sizes at both kV possibly because of reported Ca+2 ion interactions with the CAS. For the 15 wt% solutions, fibers with diameters of 298 ± 25nm, 255 ± 22nm, and 170 ± 34nm were obtained, respectively. This study showed that it is possible to create edible CAS:PUL fibers with potential use for protecting food, improving food quality, and preserving bioactive agents.

Key Words: fibers, nanoscale, preservation