Particle Size Distribution in Tomato Concentrate and Effects on Rheological Properties

Authors

  • F.W.C. DEN OUDEN,

    1. Author van Vliet is affiliated with the Food Science Dept., Wageningen Agricultural Univ., P.O. Box 8129, 6700 EV Wageningen, The Netherlands. Author den Ouden's present affiliation: H.J. Heinz b.v., P.O. Box 6, 6600 AA Elst, The Netherlands.
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  • T. VAN VLIET

    1. Author van Vliet is affiliated with the Food Science Dept., Wageningen Agricultural Univ., P.O. Box 8129, 6700 EV Wageningen, The Netherlands. Author den Ouden's present affiliation: H.J. Heinz b.v., P.O. Box 6, 6600 AA Elst, The Netherlands.
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ABSTRACT

The particle size distribution of a tomato concentrate was determined by wet sieving. Wet sieve fractions were then investigated by microscopy and a method based on laser diffraction. Both methods showed that the size of many particles was considerably larger (up to two to three times) than the diameter of the pores through which they have passed during wet sieving. This was explained by the deformability of the tomato cell wall. Effects of particle size distribution on rheological properties were studied by standardizing wet sieve fractions (dry matter, pH). Highest values for yield stress and apparent viscosity were found for the 90–125 and 125–180 μm wet sieve fractions.

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