تاثیر دو گونه صمغ کتیرای ایرانی (اصفهان و اسفراین) بر ویژگی های رئولوژیک سس مایونز

Mayonnaise as an oil in water emulsion with pH<4.1 is one of the oldest man-made emulsions that one of the most widely used sauces in Iran and in the world. Nowadays, gums are widely used to increase stability and also changing the rheological properties of mayonnaise. Gum tragacanth as a plant exudation is an Iranian native gum that it indicates a high viscosity in acidic conditions. Though, it is proved that the gum obtained from different species of Astragalus have an absolutely different physico-chemical properties. So far no comprehensive research has ever been done on the effect of different species of gum tragacanth on the rheological properties of mayonnaise sauce. In this research it was attempted to study the effect of gum tragacanth obtained from two different species of Astragalus gossypinus or Ag and Astragalus rahensis or Ar on the flow and oscillatory rheological properties of mayonnaise and was determined the effect of gum concentration and temperature on the mentioned properties. Finally, it was compared with the commercial sauce prepared by using imported gums.

The mixture was stirred for 11 min by a rotary mixer at 1000 Rpm. pH and stability tests were done. A comparison of microstructure of the mayonnaise sauce produced with different concentrations of two species of Gum tragacanth was conducted with a light microscopy equipped by a camera. Steady flow and viscoelastic properties were determined by using a controlled shear rate Rhometer.

It was shown that all treatments (type of gum and its concentration) had significant on oscillatory rheological properties. After determining the Herschel Bulklley model to describe experimental data's steady rheological tests. It was shown that the mentioned rheological factors had a significant on some of these parameters and apparent viscosity of mayonnaise sauce. A comparison of prepared mayonnaise sauce with two species of Gum tragacanth in different conditions with commercial mayonnaise sauce showed that all factors in every specific level just can make close some characteristic of produced mayonnaise to commercial sample. So the study about the effect of using mixture of different species of Gum Tragacanth with each other or with the other gums on quality of mayonnaise sauce is suggested.