New product development: Cellulose/egg white protein blend fibers

• Mixed cellulose/egg white isolate—EWI fibers were obtained.
• Addition of EWI increased the storage modulus of cellulose.
• EWI molecules formed fibrous structure bridging the voids between cellulose microfibers.
• Cellulose crystallized in the cellulose II monoclinic system.
• IR-RAMAN spectra showed the interactions between EWI and cellulose.

The aim of the research was to form mixed cellulose/egg white isolate (EWI) fibers. Cellulose was dissolved in the Schweitzer's reagent. The blend fibers were obtained by simultaneous cellulose fiber formation and acid-induced gelation of EWI in 33% sulphuric acid solution. Increased storage modulus was noted for the blend fibers in comparison to the cellulose fibers. EWI alone formed fibers which were composed of microfibers with the average diameter of about 80 nm. Cellulose fibers had a loose microstructure with about 10 μm gaps and rough surface. The addition of EWI caused that the surface of the fiber was even more rough with a tendency to form microfibers, which were not observed for cellulose alone. EWI protein molecules had the tendency to bridge the voids between cellulose microfibers. Protein in the blend fibrils formed more branched aggregates than in the EWI fibrils, which was probably caused by interactions with copper ions. Both in cellulose and cellulose/EWI fibrils, the cellulose crystallized in cellulose II monoclinic system. Reduction in COH groups was noted, which was probably caused by interactions between the cellulose and proteins molecules. EWI/cellulose interactions caused formation of β-sheet type structures.