Document Type

Theses, Ph.D


Available under a Creative Commons Attribution Non-Commercial Share Alike 4.0 International Licence



Publication Details

Successfully submitted for the award of Doctor of Philosophy (Ph.D) to the Technological University Dublin, 2010.


Horticultural products such as mushrooms are exposed to environmental conditions during their postharvest life, which may affect product quality. Loss of whiteness during storage is particularly important in the mushroom industry. Rough handling and distribution, fruiting body senescence and bacterial infections are among the main causes of mushroom discolouration. The aim of this work was to study the use of visible and hyperspectral imaging (HSI) systems for the detection and discrimination of mechanical and microbiological damage of mushrooms. This piece of research involved a) monitoring the browning of mushroom with visible computer imaging systems, b) investigating the effect of mechanical damage on the kinetics of enzymes responsible for mushroom browning, c) exploring the potential use of Vis-NIR HSI to predict PPO activity in mushroom caps and d) studying the potential application of Vis-NIR HSI for microbial and viral detection on mushroom caps and for their discrimination from mechanical damage. Results presented in this thesis show that the efficacy of commercial webcams was limited in the detection of mechanical damage on mushroom caps. Damage increased the activity of PPOs on mushroom pileipellis, but the effect of the extent of damage was not significant at the levels of study. Vis-NIR HSI showed some potential as a tool to estimate the activity of PPO enzymes on mushroom caps. The combination of HSI with chemometric tools allowed for the differentiation of mechanically and microbiologically damaged mushroom classes. Results from this study could be used for developing non-destructive monitoring systems for mechanical and microbiological damage detection and discrimination. The potential application of such systems as on-line process analytical tools would facilitate rapid assessment of mushroom quality. i