Transparency in product freshness: With facts, figures and an app

There is little doubt: milk, meat and eggs stay fresh for much longer than we think. But we often throw them out right after their best-before date, anyway. “Better safe than sorry,” or so it goes. Five METRO wholesale stores are currently trialling an app that calculates the shelf life of food more accurately. It is called FreshIndex and its purpose is to reduce food waste.


FreshIndex collects the data in the cloud and evaluates them. Microbiological models calculate microbial and bacterial growth.

A quick sip of the milk, a sniff of the meat or a closer look at the vegetables are often enough to determine whether our food is still good. But many of us are reluctant to rely on our senses alone. When we are in doubt, we often choose to throw out the items in question, especially if their best-before date has passed. We just trust best-before dates. Even though most of us are well aware that no food suddenly goes off as soon as the clock strikes midnight on the date printed on the packaging, more than four million tonnes of food are thrown away every year – in Germany alone. A 2017 survey by the GfK research institute has found that nearly half of that wastage could be avoided.

Five METRO wholesale stores are currently trialling an app that calculates the shelf life of food more accurately. It is called FreshIndex. During the field test, we interviewed Matthias Brunner, the founder of tsenso and the developer of the freshness app:

Five METRO wholesale stores are currently trialling an app that calculates the shelf life of food more accurately. It is called FreshIndex.

Matthias, how exactly does FreshIndex work?

FreshIndex gathers data from multiple sources: hygiene information from the manufacturer, storage conditions in the logistics department and in the store. Most of that information must be recorded by law, anyway. FreshIndex collects the data in the cloud and evaluates them. Microbiological models calculate microbial and bacterial growth. The result is a much more precise, real-time insight into the remaining shelf life of a product. We call it the ‘dynamic best-before date’ or DBD.

How can customers determine the DBD?

After all, it is not printed on the product. That is correct. It is dynamic and individual. We know the dates of the supply chain that takes the product to the store. Everything after that point is up to the customers: they just need to use the app on their smartphone to scan the bar code on the product. The app then asks them at what temperature they will be transporting and storing the product. They are also asked to enter the transportation time until the food reaches their refrigerator. Using that set of data, the app then determines the DBD, which is often later than the conventional best-before date. A scale displays the current freshness of the product and the remaining days until the DBD. It also shows the dynamic consumption limit or DCL, which is the date after which the product is no longer safe to eat. We are planning to add information about the nutritional value, CO2 footprint and food safety of products to the app, too.

What made you come up with the idea?

I originally wanted to develop inner-city transport services. My idea involved bookable drivers, many pizza delivery services drive one way at full load and then return empty. I thought that could be done better. In the end, that start-up did not work out, and I was left with the cold chain solution I had started to work on. With tsenso, I got to develop that solution to maturity.

And then you applied to METRO …

Yes, we took part in the METRO Accelerator for hospitality. Our contribution was a temperature monitoring system, which was not a bad idea per se. It was aimed at restaurants: we wanted to help them monitor their refrigerator, so they would no longer need to write down the temperatures manually. But while we were working on that system, many restaurant owners told us: “Once the goods are with me, I am very careful, anyway. I paid for them, after all. What I would like to know is how fresh the products are when I get them.” And FreshIndex was born.

What is your goal with FreshIndex?

We want to reduce food waste and make the freshness of products more transparent by giving people hard facts and figures.

Is FreshIndex an addition to conventional best-before dates or do you intend to replace them?

The best-before date is the date until which the producer guarantees the product properties that buyers can expect. It is a legally prescribed warranty date. That has little to do with freshness, so our system is not going to affect it. Our DBD shows buyers the actual, current freshness of their products. The most easily comprehensible way of describing it is as a more accurate best-before date. But that is misleading: best-before dates have nothing to do with freshness. Products do not go bad just because the best-before date passes. We all keep driving our cars after the warranty period, don’t we?

You are close to completing your field-testing phase. What is next?

We will evaluate the feedback we received during the study and use the results for our next development stage. At the moment, we are testing FreshIndex with two pork products. For the next steps, we want to expand FreshIndex to further product categories, such as fruit, vegetables and fish.

The temperature profile of the entire supply chain helps customers:

  • plan how and when to process a product after buying it
  • actively determine how the products ought to be stored
  • reduce food waste by using up their products on time.

About ... Matthias Brunner

Matthias Brunner, the founder of tsenso and the developer of the freshness app

Matthias Brunner is the Managing Partner of tsenso Germany. Having spent ten years working in the development, distribution and marketing of car sensors for Robert Bosch, he founded tsenso. The purpose of the start-up is to improve cold chain management by incorporating the IoT and big-data algorithms. Since his participation in the METRO/Techstars Accelerator, he has been working on FreshIndex. It aims to replace traditional, static best-before dates and improve consumer confidence and transparency in the field of food safety.
Matthias holds a doctorate in statistical physics and has published a large number of papers, for which he has been awarded the Claude Dornier Airbus Group Prize for applied research. He has a passion for turning his research findings into concrete products that help reduce global food waste. Matthias lives in Stuttgart, Germany, with his family.

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