Modelling the growth of pear postharvest fungal isolates at different temperatures. (December 2018)

• Record Type: Journal Article
• Authors: Sardella, Davide; Gatt, Ruben; Valdramidis, Vasilis P.
• Is Part Of: Food microbiology. Volume 76(2018)
• Page Start: 450
• Page End: 456
• Publication Date: 2018-12
• Subjects: Postharvest -- CMI -- Pears -- Nutrients -- Predictive mycology; Food Microbiology -- Periodicals; Aliments -- Microbiologie -- Périodiques; Food -- Microbiology; Periodicals; Food -- Microbiology -- Periodicals; Food contamination -- Periodicals; 664.001579
• DOI: 10.1016/j.fm.2018.07.010
• Languages: English
• ISSNs: 0740-0020

Abstract

Abstract: The effect of temperature on the mycelium growth kinetics of four postharvest fungal isolates (i.e., Penicillium expansum, Alternaria alternata, Botrytis cinerea and Rhizopus stolonifer ) was assessed. A cardinal model with inflection (CMI) was used to describe the effect of the temperature on the growth rate ( μ ) and the lag time ( λ ) of each isolate. Cardinal temperature values such as T min, T max and T opt were estimated and isolates were sorted according to their growth rate and lag time duration. Additionally, model validation was performed on a medium prepared from mashed pear pulp and on artificially wound-inoculated pear fruits. P. expansum was shown to be the most psychotrophic fungus with the lowest estimated T min = −8.78. Model validation on pear pulp agar showed growth rate over-prediction in the case of R. stolonifer and B. cinerea but a good correlation in the case of P. expansum and A. alternata . In vivo experiments on pear fruits showed discrepancies from the synthetic and the simulated counterparts for all the fungi with the only exception of P. expansum . Highlights: Cardinal model estimated accurately the growth rate of postharvest fungi. R. stolonifer shows the highest estimated growth rate on a synthetic medium. Validation on pear pulp showed overprediction for R. stolonifer and B. cinerea . Model had good validation capacity for P. expansum and A. alternata . It is imperative to validate fungal models with in vivo fresh pear fruit.