GroPIN constitutes a user-friendly
software which has been developed with Visual Basic for Applications and Rshiny software. The application software is based on a highly transparent predictive modeling Database for kinetic and probabilistic
models, including cardinal gamma models with interaction. The models library of
GroPIN (accessible by the users in XL environment) hosts a total of
nearly 1000
published models (=single mathematical expressions) for the growth, thermal/non-thermal inactivation and probability of growth
, including
spoilage and mycotoxigenic fungi,
bacteria and
yeasts both
in culture media and in various foods of plant (e.g., fresh-cut salads, deli
salads, berries, juices, etc.) or animal origin (meat and meat products, dairy
products). For a complete information about the included models you may execute the DataBase Analysis software.
An unlimited number of mathematical models can be introduced into the
database via
equation editor.
Utilities
Main features of GroPIN include:
(i) Simulation of microbial growth
and inactivation (log CFU vs time) under static and dynamic conditions
(ii) Plotting of secondary models
(iii) Illustration of 2D growth/no
growth interface and plots of growth probability across the interface of a
single independent variable, for multiple levels of a 2nd variable
(iv) Monte Carlo simulation based
on stochastic expression of intrinsic and extrinsic variables, and/or initial
contamination levels and physiological state (ho) of target organisms
(v) Estimation of process
lethality (F-value) and associated log reductions of dynamic time-T
(heating) profiles, based on published or user-defined Dref
and Z values
(vi) Modelling microbial
interactions of binary microbial combinations, based on Jameson effect
(vii) Modular process modelingfor simulating
interchangeable growth and inactivation microbial responses over multiple
stages of a food chain, also considering cross-contamination events or
microbial reduction, due to decontamination interventions.
Outputs
GroPIN provides both graphical (i.e., predicted lines for growth/inactivation, secondary
model, or G/NG interface and colorful response surfaces-for secondary models)
and numerical outputs, archivable in JPEG format or extracted to XL files,
respectively, in the active PC directory.
The impact on microbial behavior of a variety of critical and commonly
encountered intrinsic (preservatives, organic acids in total or
undissociate/dissociate form, salt, aw, nitrates, etc.) and extrinsic (temperature,
CO2, pressure, anaerobic conditions) factors is accounted for by the
models registered in GroPIN. The microbial responses modeled
(i.e., dependent variables) include the maximum specific growth rate, the death
rate, the lag phase duration, maximum population density, time to X-log
reduction/growth, D-values and probability of growth, depending on the selected
model category.
A search engine has been established for selecting the model of
interest. Then the user may select variables and assign values for each
variable though list boxes or by direct typing. All kinetic models, including
growth or inactivation, plus gamma models with interactions, can be simulated
under both static and dynamic conditions.
