Rheological Properties Including Tensile Fracture Stress of Semolina Extrudates Influenced by Moisture Content
Article first published online: 20 JUL 2006
Journal of Food Science
Volume 62, Issue 4, pages 813–820, July 1997
How to Cite
LIU, H., QI, J. and HAYAKAWA, K. (1997), Rheological Properties Including Tensile Fracture Stress of Semolina Extrudates Influenced by Moisture Content. Journal of Food Science, 62: 813–820. doi: 10.1111/j.1365-2621.1997.tb15461.x
- Issue published online: 20 JUL 2006
- Article first published online: 20 JUL 2006
- Ms received 8/21/96; revised 3/9/97; accepted 3/13/97.
- rheological properties;
- wheat flour;
- moisture dependency
Semolina extrudates were reshaped, immediately after extrusion to form 0.5 mm thick × 2 mm wide × 130 mm long strips. Moisture content (W) was adjusted to 5 to 39% (dry basis) equilibrating in desiccators containing saturated salt solutions. The following tensile rheological properties of the prepared samples were determined at room temperature (21-24°C) using a Rheometrics solid analyzer: Young modulus (E), yield stress (σy), fracture stress (σc) and fracture stain (ɛc). Each of E, σy and σc was fitted by a semilogorithmically linear function of W with a negative slope. The property ɛc fitted two semilogarithmically linear functions: for W < 24.2% a line with a positive slope and for W > 24.2% a line with near zero slope. Such data for moisture ranges used in conventional pasta drying can help to optimize conditions for pasta production without stress cracking.