Modelling kinetics of watercress (Nasturtium officinale) colour changes due to heat and thermosonication treatments

Rui M. S. Cruz, Margarida C. Vieira, Cristina L. M. Silva*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

48 Citations (Scopus)


Watercress (Nasturtium officinale) colour changes due to blanching by heat and a combined treatment of heat/ultrasound (thermosonication) were studied in the temperature range of 82.5 to 92.5 °C. The application of thermosonication was intended to enable less severe blanching treatments and, therefore, improve the quality of the blanched product. The thermosonication blanching processes promoted changes of the green colour (an parameter) at a higher rate (P < 0.05), when compared with the heat blanching processes. No significant differences (P > 0.05) were detected between heat and thermosonication blanching processes in terms of the colour parameters Ln, bn and TCD changes. In both treatments, a fractional first order model fitted well the experimental data for Ln, an and bn (RH2 = 0.99; RTs2 = 0.99) and TCD (RH2 = 0.92; RTs2 = 0.96) colour parameters. The chlorophylls content showed no significant differences (P > 0.05) between thermally treated and thermosonicated watercress samples. The present findings will help to evaluate the effectiveness of thermosonication as a novel process to replace the classical heat treatment. Industrial relevance: Conventional blanching commonly results in severe losses or destruction of nutrients due to process intensity and extended process times. Consequently, the attempts to use the synergistic effects of heat and ultrasound (at least) for enzyme inactivation are of high relevance. The results, although not conclusive, indicate, that they may aid optimization of blanching processes.

Original languageEnglish
Pages (from-to)244-252
Number of pages9
JournalInnovative Food Science and Emerging Technologies
Issue number2
Publication statusPublished - 1 Jun 2007


  • Chlorophylls
  • Colour changes
  • Heat blanching
  • Kinetics modelling
  • Thermosonication
  • Watercress (Nasturtium officinale)


Dive into the research topics of 'Modelling kinetics of watercress (Nasturtium officinale) colour changes due to heat and thermosonication treatments'. Together they form a unique fingerprint.

Cite this