A time temperature indicator (TTI) is a device or smart label that shows the accumulated time-temperature history of a product. Time temperature indicators are commonly used on

food Food is any substance consumed by an organism for Nutrient, nutritional support. Food is usually of plant, animal, or Fungus, fungal origin and contains essential nutrients such as carbohydrates, fats, protein (nutrient), proteins, vitamins, ...

pharmaceutical Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy ( pharmacotherapy) is an important part of the ...

, and medical products to indicate exposure to excessive temperature (and time at temperature). In contrast, a temperature data logger measures and records the temperatures for a specified time period. The digital data can be downloaded and analyzed.

Type

By timespan

The basic types of time-temperature indicators include: * Partial history indicators: These are time-temperature indicators that provide a visual indication of whether a product has been exposed to temperatures outside the recommended range during a specific portion of its life cycle. * Full history indicators: Unlike partial history indicators, these give an indication of whether the product has been exposed to temperatures outside the recommended range during the entire life cycle. * Critical temperature indicators: These monitor a critical temperature threshold that, if exceeded, may cause irreversible damage to the product. Digital temperature data loggers are available to indicate the full temperature history of a shipment to help identify the time period that out-of- tolerance temperatures were encountered. This temperature history can be used to calculate the loss of

shelf life Shelf life is the length of time that a commodity may be stored without becoming unfit for use, consumption, or sale. In other words, it might refer to whether a commodity should no longer be on a pantry shelf (unfit for use), or no longer on a s ...

or the likelihood of spoilage. These small recorders are also used to identify the time (and thus location) of a shipment when the problem occurred, which allows for corrective action.

By technology

There are a large number of different time temperature indicators available in the market, based on different technologies. To the degree that these physical changes in the indicator match the degradation rate of the food, the indicator can help indicate probable food degradation. *

Enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

-based TTIs: an enzyme changes the color of the dye on a piece of filter paper as time passes *

Microbe A microorganism, or microbe, is an organism of microscopic size, which may exist in its single-celled form or as a colony of cells. The possible existence of unseen microbial life was suspected from antiquity, with an early attestation in ...

-based TTIs: a mixture containing dye and bacteria changes color as bacteria grow and chemically changes the dye * Digital TTIs: a miniature temperature data logger can be attached to the item.

RFID Radio-frequency identification (RFID) uses electromagnetic fields to automatically identify and track tags attached to objects. An RFID system consists of a tiny radio transponder called a tag, a radio receiver, and a transmitter. When tri ...

communication can be used to retrieve the temperature log.

TTIs in the food industry

Time-temperature indicators can be used on food products that are dependent on a controlled temperature environment. Certain technologies can also be used for

frozen food Freezing food Food preservation, preserves it from the time it is prepared to the time it is eaten. Since early times, farmers, fishermen, and trappers have preserved grains and produce in unheated buildings during the winter season. Freezing foo ...

and the

cold chain A cold chain is a supply chain that uses refrigeration to maintain perishable goods, such as pharmaceuticals, produce or other goods that are temperature-sensitive. Common goods, sometimes called cool cargo, distributed in cold chains include fr ...

. Meals, Ready-to-Eat (MREs) from the US military have included "Fresh-Check" TTIs on the cardboard boxes since 1997 to help estimate their shelf lives.

Benefits

Surveys within the European Union projects "Freshlabel" and "Chill-on" have shown positive feedback from

consumer A consumer is a person or a group who intends to order, or use purchased goods, products, or services primarily for personal, social, family, household and similar needs, who is not directly related to entrepreneurial or business activities. ...

s on the use of TTIs on food products. As TTIs help assure the cold chain of food products, they are expected to reduce the amount of

food waste The causes of food going uneaten are numerous and occur throughout the food system, during food production, production, food processing, processing, Food distribution, distribution, Grocery store, retail and food service sales, and Social clas ...

, as well as reducing the number of

foodborne illness Foodborne illness (also known as foodborne disease and food poisoning) is any illness resulting from the contamination of food by pathogenic bacteria, viruses, or parasites, as well as prions (the agents of mad cow disease), and toxins such ...

es.

Regulation

The

World Health Organization The World Health Organization (WHO) is a list of specialized agencies of the United Nations, specialized agency of the United Nations which coordinates responses to international public health issues and emergencies. It is headquartered in Gen ...

regulates the use of TTIs for certain medical products. There is extensive regulation by the FDA on the use of TTIs on US seafood products.

References

General References

* ASTM F1416 Standard Guide for Selection of Time-Temperature Indicators * Yam, K. L., "Encyclopedia of Packaging Technology", John Wiley & Sons, 2009, * Taoukis, P. and T.P. Labuza. 2003. Time temperature indicators. In: Novel Food Packaging Techniques. R. Ahvenainen (ed.). Woodhead Publ., Cambridge, UK.

External links

FDA regulation on the use of TTI's in the seafood industry

Article on the introduction of a TTI at a large food producer

WRAP Food Waste Report
(1.4 MB)

Article on the introduction of a TTI at a food producer in Switzerland
{{packaging Food safety Drug safety Temperature control Packaging