Premium
VISCOELASTICITY OF A SIMULATED POLYMER AND COMPARISON WITH CHICKPEA FLOUR DOUGHS
Author(s) -
YADAV NIDHI,
ROOPA B.S.,
BHATTACHARYA SUVENDU
Publication year - 2006
Publication title -
journal of food process engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.507
H-Index - 45
eISSN - 1745-4530
pISSN - 0145-8876
DOI - 10.1111/j.1745-4530.2006.00046.x
Subject(s) - viscoelasticity , materials science , composite material , compression (physics) , stress relaxation , elasticity (physics) , polymer , nonlinear system , water content , compressive strength , crosshead , creep , flexural strength , physics , geotechnical engineering , quantum mechanics , engineering
An integrated approach consisting of compression and stress relaxation is performed with a simulated model system of poly dimethyl siloxane (PDMS), a viscoelastic polymer material when the compressive strain, height of sample and crosshead speed were varied. The parameters derived are the forces at the end of compression and relaxation, energy for compression and the extent of elasticity of the sample based on the ratios of forces as well as the proposed energy values. The results were verified with food doughs undergoing large deformations that show a nonlinear behavior. The proposed extent of elasticity based on the ratios of energy stored and compression can be used as an index for the characterization of viscoelasticity. A nonlinear three‐parameter model had also been proposed to predict the stress decay characteristics as a function of time, which was found suitable for the PDMS system, and was better than the two‐parameter Peleg model as judged by lower variance values (0.0006–0.018 and 0.002–0.048, respectively). Further, an actual system of food doughs in the form of chickpea ( Cicer arietinum L.) flour dough was used to verify the proposed model and viscoelastic index at different moisture contents (27–39%) subjected to compressive strains of 25–75%. The nonlinear relaxation characteristics of the food dough are sensitive to moisture content as well as to strain level.