Abstract: The rheological properties and the size and molecular weight distribution of pectin of tomato pulps broken at different temperatures were investigated.The average molecular weight of pectic substances in tomato polps increased with the increasing of breaking temperatures,while the value decreased when tomato was broken up to 90℃.Dynamic shear data revealed that tomato pulps broken at 80℃and 85℃had relatively high storage moduli.Which dependent on oscillatory frequencies to some extent.So the pulps exhibited weak gel properties.The positions of crossover point of storage moduli G′and loss moduli G″moved toward low frequencies with the increase of breaking temperature.It reflected that the higher the temperature was,the more macromolecular substances were retained in tamato pulp,and also stronger the elastic properties became,and vice versa.

Key words:  , Tomato Breaking temperature Pectin Storage modulus Loss modulus；