لخّصلي

A more direct assessment of the condition of the packed food or beverages is provided by the indicators, which signalize any change in packed product or its surrounding (e.g. pH, temperature) usually by visual changes (e.g. by changing the colour) (Sohail et al. 2018).

A more direct assessment of the condition of the packed food or beverages is
provided by the indicators, which signalize any change in packed product or its
surrounding (e.g. pH, temperature) usually by visual changes (e.g. by changing the
colour) (Sohail et al. 2018). The indicators have usually simplified recognition and
transduction system in comparison to the sensors. Indicators provide direct and
noticeable to the naked eye change the appearance of the their distinctive elements in
the presence of the target phenomenon. The greatest challenge in the design of a
usable intelligent packaging system is the identification of a reliable relationship
between the measurable indicator and changes in food product quality and/or safety
being under observation (Müller and Schmid 2019). The most popular indicators
applied in intelligent food packaging are time-temperature indicators (TTI) mainly
because of the simplicity of its construction, low cost, ease of calibration and
interpretation of results compared to other indicators and sensors (Han et al.
2018). Packaging tightness indicators (gas indicators) and food freshness indicators
(including ripening indicators and microbial growth indicators) are also becoming
more and more popular