Improving the rheological characteristics of tomato paste is an important factor for consumers and is the main index in classification and standardization of this product. Also, it is an important commercial index.By improving the appearance viscosity, we can reduce the amount of tomato for getting an identical level of quality so the total coast is reduced. That it is so important for foreign consumer. There isn’t any proper standard for consistency and tomato paste viscosity in Iran. In this research, we calibrate BOSTWICK CONSISTOMETER and rotational viscometer in three brix: 12, 16, 20 and three temperatures: 25, 35, 45oc in four interval: 5, 15, 30, 60 seconds of BOSTWICK time. Finally the results showed that the optimum time for their calibration is 30 seconds of BOSTWICK time.

In this research, it was tried to consider and determine standard index with BOSTWICK CONSISTOMETER with tomato paste produced through cold break process .However, the consistency and viscosity are known as an important qualitative characteristics of tomato paste, they don’t exist in Iran’s standard tables and there aren’t any standards in working by BOSTWICK CONSISTOMETER for measuring tomato paste “consistencey . In this research, we standardize the BOSTWICK CONSISTOMETER using coldbreak tomato paste in three brix : 12, 16, 20.and three temperatures: 25, 35, 45oC . The results show that room temperature and 12, 16 brix and 30 seconds are the optimum parameter value for working by BOSTWICK CONSISTOMETER. This is consistent with the world standards.

Tomato concentrated products were diluted up to 12 percent solids to measure their consistency by Bostwich CONSISTOMETER. The evaluation of the consistency of tomato concentrated with different Brixes showed that the error in consistency measurement of tomato concentrated by Bostwich method increased as the Brix increased. The studies indicated that the drying rate of insoluble solids and the lacking of reconstituting properties of them were caused error in the measurement of paste consistancy (especially at high Brixes). In this research, the effect of variety, tomato concentrated Brix and the temperature of consistency measurement were evaluated to determine the error changes in Bostwich CONSISTOMETER and to modify it. The results showed that the variety had no effect on the accuracy of consistency measurement by Bostwich method, but Brix and temperature had a very significant effect on the accuracy of this assay and thus the error of Bostwich CONSISTOMETER increased, especially at high Brixes. It was concluded that heating of diluted tomato concentrated (up to 45 Co) and then cooling it can decrease the error of consistency measurement considerably. Also, the consistency can be estimated accurately by using the regration between Brix, temperature and Bostwich consistency (R2=0.94).

used at 5 levels: 0, 0.25, 0.5, 0.75 and 1%. Viscosity, BOSTWICK consistency, textural hardness, color parameters(L, a, b) and sensory characteristics of the five low fat cream samples with 20% fat were compared with the 30% fat control. The results indicated that gelatin was able to improve the properties of low fat cream samples towards the 30% control. In terms of color parameters the low fat creams with 0.5% gelatin and more were similar to the control with 30% fat. Sensory evaluation tests showed that the perception scores of the low fat creams with 0.75 and 1% gelatin were the same as the 30% fat control.