Temperature Control and Data Exchange in Food Supply Chains: Current Situation and the Applicability of a Digitalized System of Time–Temperature-Indicators to Optimize Temperature Monitoring in Different Cold Chains

The current situation of temperature monitoring in perishable food supply chains and the optimization of temperature control was studied by combining two approaches. First, a survey among German companies (production, processing, logistics, wholesale, retail) was conducted to analyze the current temperature monitoring and data management conditions as well as the use of novel monitoring systems, such as Time–Temperature-Indicators (TTIs). Second, the temperature conditions in three different supply chains (B2C for raw pork sausage, B2B for fish, B2C e-commerce for mixed products) were investigated to analyze the applicability of TTIs with an app-based read-out system to identify weak points and to optimize cold chain management under practical conditions. The results of the survey showed that mainly static conditions are tested along the supply chain. Thus, the actors rely mostly on visual inspection or best-before date labeling while TTIs are not widely used. Currently, temperature data are barely exchanged by stakeholders. In the B2C chain, mean temperatures on different pallet levels were comparable, also reflected by TTIs and the app-based read-out system, respectively. In the B2B chain, temperature interruptions during the unloading process were detected, revealing main challenges in perishable supply chains. Temperature monitoring by TTIs on a box level was possible by positioning the label close to the product. Results in the e-commerce sector showed heterogeneous conditions in different boxes depending on initial product temperatures and loading. TTIs and the app-based read-out system showed reliable results based on different temperature scenarios, when TTIs are positioned close to the most sensitive product.