Little research has still been published on gel elasticity. To this end, noodle sheets were indented with spherical probes of differing tip radii. Loads were ramped up to ∼6-8% nominal strain, the displacement then being held constant while the specimen relaxed. Flour-based noodles were significantly less elastic than starch-based ones. Data for tips of 3.175 mm and 1.65 mm radius gave consistent results for the elastic modulus, the variability being least with the latter. The smallest (0.72 mm) indenter was least consistent, often producing higher values. To examine if results with different probe sizes reflected characteristic gel microstructural dimensions, non-indented and post-indented specimens of wet sweet potato noodle sheets were imaged by AFM. Preliminary indications were that 0.72 mm probes more likely contacted swollen (disrupted) starch granules than surrounding matrix. If most deformation in gels takes place within the matrix, an indenter 'size effect' might be explained by granule size.
|Number of pages||8|
|Journal||Journal of Food Engineering|
|State||Published - 1 May 2016|
- Average relaxation ratio
- Blunt indentation
- Gel texture
- Mechanical behavior