Shelf life is the time-span where the product is in good conditions for consumption,
from either safety or quality points of view. Shelf life is defined to guarantee food safety
(“use-by” date), or to guarantee both safety and quality food standards (“best-before
date”).
The aim of active packaging systems is to extend shelf-life by releasing active
substances into the food product. The active packaging is composed of one or several
layers. Each layer may contain a given concentration of the active substance whose
release velocity will depend on the layer material. An adequate selection of the layer
composition and active substance initial concentration will have an impact on shelf life.
In this work, we use mathematical models in combination with optimization methods to
(i) design the optimal configuration of the smart packaging for both “use-by date” and
“best-before date” criteria; and (ii) assess and predict shelf life changes according to
variations on storage conditions. Two different types of models are used: (i) release of
the active substance into the food product [1]; and (ii) shelf-life evolution as a function
of storage conditions and active substance concentration in the food [2].
The growth of Listeria monocytogenes, which affects widely consumed products, is
used as the safety indicator. The KI-value, which is related to ATP-degradation
compounds, is used as the quality indicator. Carvacrol is a substance that inhibits
bacterial growth. In this work, it will be used as the active substance to limit the growth
of Listeria monocytogenes (food safety) and other spoilage bacteria responsible for
quality changes.
The optimal design allows for an increase in shelf-life of around 24% as compared with
the fish product without active packaging
