Rheological Characterization of Low Fat Sesame Paste Blended With Date Syrup

Abstract

In this paper, the time-dependent flow behavior of reduced fat sesame paste with date syrup were assessed using Brookfield rotational viscometer as a function of fat substitutes (guar gum, xanthan, and starch) at three levels and shearing time. Two models were used to predict the time-dependent behavior, known as, first-order stress decay with a zero equilibrium stress and Weltman models. It was found that time-dependent behavior of samples was adequately fitted with these models. All blends exhibited the thixotropic behavior and thixotropy of samples increased with increasing shear rate. For Weltman model, the A and B constants appeared in the range of 189.2–730.6 Pa and 0.090–1.571 Pa, respectively. While for first-order stress decay model, the initial shear stress (τ₀) was in the range of 197–794 Pa, and the breakdown rate constant (K) varied in the range of 0.002–0.018 s⁻¹. The presence of fat substitutes generally resulted in an increase of viscosity and thixotropy of blends in comparison with the blank.

Keywords:

• Rheology
• Weltman model
• Kinetic model
• Starch
• Xanthan
• Guar

ACKNOWLEDGMENT

The authors would like to sincerely thank the Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, for the laboratory facility of this research and from the Simorgh Company for financial support.

Notes

19. Nutrition Labeling Act of 1990, Publication No. 101–535, 104 Stat 2353.