Rheological and structural characterization of tomato paste and its influence on the quality of ketchup

Research output: Contribution to journalArticle


Three hot break tomato pastes were investigated to determine the effect of their characteristics on the properties of tomato ketchup, processed in an industrial-scale facility (i.e. diluted, heated, homogenized and cooled). Pastes and ketchups were characterized by particle size distribution, volume fraction, and rheological behavior in steady and dynamic shear. The ketchups were also subjected to sensory assessment. The processing of pastes into ketchups induced large structural changes, which were reflected in all parameters studied. The volume fraction of solids (φ) accurately reflected the changes that the paste suspensions underwent during processing and it appeared to be a good predictor of the flow behavior of both the pastes and the ketchups. The corresponding flow curves were found to be well described by the Carreau model in a large range of shear rates and concentrations. However, the rheological characteristics of the commercial pastes studied did not directly correlate to those of the corresponding ketchups. Instead, our results suggest that the change in structure induced by processing might be governed by other properties of the paste, such as the fraction of small and large particles and their sensitivity to breakage, together with the viscosity of the aqueous phase.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Food Engineering


  • Rheology, Structure, Tomato paste, Quality, Ketchup
Original languageEnglish
Pages (from-to)1289-1300
JournalLWT - Food Science and Technology
Issue number7
Publication statusPublished - 2008
Publication categoryResearch

Bibliographic note

Article in Press, Corrected Proof Available online 3 September 2007