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The rheological behaviour of low fat soy‐based salad dressing
Author(s) -
Zhang Chi,
Quek Siew Young,
Lam Gloria,
Easteal Allan J.
Publication year - 2008
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1111/j.1365-2621.2008.01852.x
Subject(s) - rheology , food science , soy protein , apparent viscosity , shear thinning , viscosity , chemistry , materials science , composite material
Summary Low fat soy‐based salad dressings were formulated with different oil levels (3%, 13% and 23%) and emulsifiers (whey protein concentrate, soy‐lecithin and sodium caseinate) using either blender or ultra‐turrax (UT) homogeniser. Results showed that the rheological behaviour of these samples were highly dependent on the oil content, emulsifiers and blending methods. The UT method produced samples with better viscosity and have droplet size of 2–100 μm. Samples containing higher oil level have higher viscosity, smaller droplet size, larger G ′ and G ″ values. All samples show a shear‐thinning effect and larger G ′ than G ″, indicating the elastic nature of the samples. A quantity Q ( t )% was applied to estimate the elasticity and the values were found to be in the range 22.8–85.2%. G ′ and G ″ were found to decrease with increased temperature. However, tan δ increased slightly with temperature; the values ranged from 0.2 to 0.4 at 5 °C to 0.3–0.5 at 25 °C. Current results demonstrated that the formulated samples have good stability compared with commercial products.