Evaluation of the chemical composition and colour in long-life tomatoes (Lycopersicon esculentum Mill) dehydrated by combined drying methods

Authors

  • Aline Jorge,

    Corresponding author
    1. Department of Production Engineering, Federal Technological University of Parana (UTFPR), Federal University of Technology Av. Monteiro Lobato km 04, Ponta Grossa, PR, Brazil
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  • Denise Milleo Almeida,

    1. Department of Production Engineering, Federal Technological University of Parana (UTFPR), Federal University of Technology Av. Monteiro Lobato km 04, Ponta Grossa, PR, Brazil
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  • Maria Helene Giovanetti Canteri,

    1. Department of Production Engineering, Federal Technological University of Parana (UTFPR), Federal University of Technology Av. Monteiro Lobato km 04, Ponta Grossa, PR, Brazil
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  • Thiago Sequinel,

    1. Department of Physical Chemistry, UNESP – Institute of Chemistry, Araraquara, SP, Brazil
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  • Evaldo Toniolo Kubaski,

    1. State University of Ponta Grossa, Department of Materials Engineering, Ponta Grossa, PR, Brazil
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  • Sergio Mazurek Tebcherani

    1. Department of Production Engineering, Federal Technological University of Parana (UTFPR), Federal University of Technology Av. Monteiro Lobato km 04, Ponta Grossa, PR, Brazil
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Summary

When tomatoes are submitted to treatments of drying, depending on the parameters and methods used, the concentration or degradation of nutrients can occur. The changes in the composition and colour were verified when different drying processes were used. Freeze drying, oven drying, the combination of both and also the effect of the pretreatment (blanching) using steam were studied. The fresh tomato composition was compared with the composition of dehydrated tomato powder. After dehydration, the moisture content reduced 78% from the total initial moisture. In addition, a nutrient concentration was observed with an increase of about 57% of citric acid content and 3% in the pH. The ash content also increased from 0.53% to 8% (15 times) and 60%, the carbohydrates from 3.94% to 60% (15 times) and the proteins were increased from 1% to 11% (10 times). The blanching resulted in different types of changes, such as greater stability for the proteins, carbohydrates, fat, lycopene and β-carotene.

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