Structural, viscoelastic, and emulsifying properties of shrimp chitin nanowhisker dispersions as a function of acidic pHs
Joaquín Gómez‐Estaca, Clara A. Tovar, P. Montero, M.C. Gómez‐Guillén
Abstract
Ultrastructural, hydrodynamic, rheological, and emulsifying properties of chitin nanowhisker dispersions from commercial (C) and laboratory (L) origin were analyzed at pHs 2–3.5. Nanowhiskers were rod-like shaped and their hydrodynamic properties changed in range: particle size: 90–560 nm; ζ potential: 26–42 mV; polydispersity 0.175–0.850. Flow curves indicated a shear-thinning behavior for both samples. At pH 2 dispersions were more consistent than at pH 3.5, but in both cases L showed higher consistency than C. Both C and L exhibited a non-stationary (thixotropic) flow at pH ≥ 2.5. The coexistence of two shear-induced domains was found in the oscillatory tests. The emulsifying ability of both C and L samples at a low (0.5%) concentration was dependent on pH. So, at pH 2, the L sample showed a greater emulsifying ability (98%) and emulsion stability (92-90%) than the C sample (emulsion stability ≈74%).