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Effect of Heat Schock on Browning-Related Enzymes in Minimally Processed Iceberg Lettuce and Crude Extracts
  • Ana Belen Martin-Diana, Dublin Institute of Technology
  • Daniel Rico, Dublin Institute of Technology
  • Catherine Barry-Ryan, Dublin Institute of Technology
  • Jemina Mulcahy, Dublin Institute of Technology
  • Jesus Maria Frias, Dublin Institute of Technology
  • Gary Henehan, Dublin Institute of Technology
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This item is available under a Creative Commons License for non-commercial use only
Publication Details

Biosciences, Biotechnology, Biochemistry, Vol.69, 9, 2005, pp.1677-1685

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The effects of heat shock on PPO and POD activity in minimally processed Iceberg lettuce was examined during storage (10 days). The results were compared with the effect of temperature on crude extracts of these enzymes (in vitro analysis). Fresh-cut lettuce washed at 50 °C showed significantly lower PPO and POD activity throughout storage than lettuce washed at 4 °C and 25 °C. These results were consistent with a sensory analysis in which the panellists found the lowest browning scores in those samples treated at 50 °C. When PPO and POD were analysed in vitro, the samples treated at 50 °C showed a rapid loss of POD activity and a similar but slower loss of PPO activity in all tissues, while incubation at 4 °C and 25 °C showed no significant loss of activity. While heat shock did not lead to significant loss of activity it did repress the synthesis of PPO and POD during storage.
Citation Information
Martin-Diana, A., Rico, D., Barry-Ryan, C., Mulcahy, J., Frias, J., Henehan, G.:Effect of Heat Schock on Browning-Related Enzymes in Minimally Processed Iceberg Lettuce and Crude Extracts.Biosciences, Biotechnology, Biochemistry, Vol.69, 9, 2005, pp.1677-1685. doi: 10.1271/bbb.69.1677