A smart sensor that tracks storage temperature and shows the remaining days of shelf life, called Keep it, can help consumers reduce food waste. 

A study by Wageningen University and Research (WUR) had 1,500 Dutch customers of HelloFresh use Keep It and has sparked a debate about the role of smart technology in reducing household food waste.

However, consumers will need to understand how such devices work in detail to enhance mainstream acceptance, the researchers note.

Keep It is a small, plastic non-invasive tracking device that measures the temperature of the food products it is attached to, resembling a horizontal thermometer.

When the product is stored in a warm place, the indicator moves quickly. When the product is kept cool, the indicator moves slowly. When the indicator reaches zero, the product is no longer edible. 

The researchers found that the Keep It concept was well understood by consumers and, “perceived as positive, reliable, useful, intuitive and value-adding.”

The study comes as food waste becomes a mounting issue worldwide. According to European Commission data from 2016, 88 million tons of food is wasted in Europe and 10 percent of it is attributable to expiry date labeling.
The researchers aimed to test how shelf life sensors can help consumers make better decisions. 

“Various retailers in Norway have been using the Keep It indicator since 2013,” says Gertrude Zeinstra, project coordinator and researcher at Wageningen Food & Biobased Research. 

“We wanted to know whether Dutch and Flemish consumers would also be open to it, how they would handle it and whether they understand how the indicator works.” 

Of the 1,485 HelloFresh, 421 households received their meal box at home with a Keep It indicator on the fresh salmon packaging. They also received a flyer about the indicator and general date marking information. 

The control group – 1,064 households – did not receive a Keep It indicator on their pre-packed salmon: they received a flyer with general date-marking information. 

Instead, they saw a picture of the Keep-it indicator and a short explanation in an online survey about both groups’ perceptions, experiences and expectations with regard to the indicator.
In general, both groups were positive about the Keep It indicator. Between 60 percent and 90 percent of the respondents agreed that the indicator was “positive.”

Moreover, 76 percent thought that the indicator would help them waste less food, Zeinstra notes. 

Testing how the device would influence food freshness perception, the number of participants who would still eat a product beyond the expiry date increased from 2 percent (without the Keep It indicator) to 20 percent (Keep It showing two remaining days of shelf life).

On the other hand, when the printed on-pack date showed a longer shelf life than Keep It indicated, (in roughly 45 percent of the cases in the study), consumers avoided eating the potentially harmful food.

“This indicates a kind of trust in the indicator and shows the potential of a time-temperature indicator in food waste reduction,” reads the study.

Before introducing Keep It on the market, the researchers recommend explaining how the indicator works. Showing consumers how the indicator works practically, as opposed to just the pictures in the online survey, are projected to enhance acceptance. 

Food waste prevention tech
Creative digital technologies are increasingly coming to the fore to prevent food waste. Last year, WUR was involved in a study researching Too Good To Go.

The app allows consumers to purchase a “Magic Box” with a surprise assortment of food products from participating stores that would have otherwise been thrown away. 

Earlier this month, a packaging tech consortium designed a smart device called Deksel. The lid prototype installed on food jars illuminates four green LED lights, diminishing over time to inform consumers how long they can eat their contents before spoiling. A red light indicates the contents should be thrown away.

Across the Atlantic, Canada-based printed electronics company Ynvisible Interactive developed interactive labels that can detect spoiled food based on reactive ink that senses gas concentration within food packages.