Manski JM, van der Goot AJ, Boom RM. Formation of Fibrous Materials from Dense Calcium Caseinate Dispersions.
Biomacromolecules 2007;
8:1271-9. [PMID:
17326681 DOI:
10.1021/bm061008p]
[Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Application of shear and cross-linking enzyme transglutaminase (Tgase) induced fibrous hierarchical structures in dense (30% w/w) calcium caseinate (Ca-caseinate) dispersions. Using Tgase was essential for the anisotropic structure formation. The fibrous materials showed anisotropy on both micro- and macroscale as determined with scanning electron microscopy (SEM) and mechanical analyses, respectively. SEM revealed protein fibers with a diameter of approximately 100-200 nm; visually, we observed fibers of about 1 mm. Both shear and Tgase affected the reinforcement of the fibers to a large extent, whereas the mechanical properties in the direction perpendicular to the shear flow remained constant. Shearing Ca-caseinate without Tgase yielded a slightly anisotropic layered structure. Both cross-linking in the absence of shear and cross-linking during mixing resulted in gels without alignment. The formation of shear- and enzyme-induced anisotropic structures was explained by aligning of protein aggregates due to shear and concurrent solidification of the aligned protein aggregates.
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