1. Why is active and intelligent packaging necessary?

    Food requirements: Depending on the requirements of packed food, the application of appropriate active packaging systems can significantly reduce food quality deterioration. Food conditions that may play an important role in the shelf life of packed food include physiological processes (e.g. respiration of fresh fruits and vegetables), chemical reactions (e.g. lipid oxidation), physical processes (e.g. dehydration) and microbiological aspects (e.g. spoilage by microorganisms). On the other hand intelligent or smart packaging indicate the quality of the product. The active packaging and intelligent or smart packaging systems are combined in the platform to AIP technologies.

  2. Types of Active Principles

    Active packaging describes mainly food packaging that interacts chemically or biologically with its contents or head space to extend shelf-life or. Since oxygen scavenging sachets were introduced to the Japanese market in 1978 the packaging industry has extended the traditional packaging tasks such as transport, protection or communication by active features. Packaging may be termed active when it affects one or more attributes of the packaging in a lasting and desired way. Oxygen scavengers are not the only applications used in active packaging. Besides the oxygen scavengers, antimicrobial agents, moisture absorbers, ethylene absorbers, ethanol and carbon dioxide emitters can be used as active features in order to address the weak points in the shelf life of packed goods.

    • Oxygen scavengers are the best known and most widely used active packaging technologies today. They had been designed to remove residual oxygen from the headspace of the package and/or to achieve zero-permeation. To achieve this goal a chemical absorbent is incorporated into the packaging material or added inside the package by means of sachets or labels. Also, the use of entrapped oxygen-consuming micro-organisms has been proposed as an alternative. Common food applications for oxygen scavenger packaging include oxygen sensitive beverages, fresh products, e.g. fresh pastas, snack food, ready-to-prepare and ready-to-eat produces.

    • Antimicrobial agents incorporated into packaging materials are used more and more during the last years for food packaging. The objective of these agents is to control or to inhibit the growth of non-desirable micro-organisms on the food surface. These particles are often transported (migration) from the package to the food surface and are already used as coatings on different polymeric materials or in the mass of the polymer. The activity of these antimicrobial agents is carried out either by contact of micro-organisms onto the internal face of the packaging material, either directly in the food by emission or slow diffusion of the antimicrobial agent from the packaging material to the food. The packaging material containing the active substance should be sufficiently permeable to allow diffusion and controlled release during storage.

  3. Types of Intelligent and Smart Principles

    Intelligent or smart packaging is a special form of active packaging. One of the main purposes is to indicate whether the quality of the product has decreased before the product deteriorates. Time-temperature indicators (TTIs) are the most used applications in the field of intelligent packaging. Further Applications with growth prospect are freshness indicators and tracking services via intelligent expiry date label.

    • A time-temperature indicator (TTI) is a small measuring device attached to the package surface that exploits a change in a physical or physiochemical property to produce irreversible evidence of exceeding a predetermined temperature threshold or record the cumulative time-temperature history. TTIs are working by physical, enzymatic or chemical reactions and are increasingly used to track both chilled and frozen foods. A TTI should be easy to activate and the observable colour change or colour development should correlate with the negative influence of the microbiological process. TTIs are provided in different versions, with different activation temperatures and flow times. Depending on their type, they should be appropriate for specific product categories with defined temperature sensitivity.

    • Freshness indicators are attached inside the packaging and since they are dependent on any inference from temperature history, they signal directly product quality of the packed food. They detect volatile or non-volatile compounds or changes in the product itself. Used methods are visible indicator tags in contact with package headspace, labels and optical detectors. Freshness indicators detect the presence of microbiological metabolites. The indicator systems for metabolites include colour change of a dye or liquid crystals, formation of colour compounds, changes in optical properties or a miniaturised electronic nose.
      The sole use of freshness indicators can be enhanced, and most important of all, brought to a universally interpretable level by extending the indicator with interpretation instructions which are accepted and understood by all parties involved in the handling chain of the perishable goods in question.

    • Tracking services: If the quality of goods is limited by expiry, it becomes important to meet correct decisions upon their disposal during transportation, storage and sale, otherwise, losses may occur due to premature expiry before reaching the point of sale, or food safety rules could be violated. The key decisions preventing premature spoilage can be made in following operational areas: i) food processing ii) packing process iii) logistic and shelf management at the point of sale. It is evident that such decisions can only be met properly if information about the status of goods is provided, i.e., the packed good can be tracked over the delivery and storage processes.