Smart food storage and transport
Storing and transporting food is a special challenge. This is due, among other things, to the perishability of fresh food products and the special requirements for ambient temperatures. There are a number of legal regulations and hygiene rules that must be observed during storage and also during transport. Ultimately, the aim is to ensure food safety for consumers. In the warehouses, suitable environmental conditions - especially with regard to temperatures - must be established for different product categories. In addition, there are requirements for humidity, CO2 content (for ripening warehouses), air circulation, and much more. In addition, precautions and defence measures against pest infestation must be taken.
There are currently 700 regulations and ordinances relevant to food storage in Germany. Food law is not only determined by laws, ordinances and statutory instruments of the Federal Government and the Länder, but also by laws and ordinances of the European Union. Of particular importance for the food sector are Regulations (EC) No. 852/2004 (food hygiene) and (EC) No. 853/2004 (hygiene rules for animal foodstuffs) as well as the Federal Food Hygiene Regulation (LMHV). According to the Arbeitsgemeinschaft Kälteforum dti/VDKL (1), the frozen food sector is subject to its own regulations and ordinances. For example, Regulation (EC) No. 37/2005 on the monitoring of temperatures in the means of transport, warehousing and storage of quick-frozen foodstuffs regulates the specific implementation of temperature controls. Basic requirements for the handling of frozen goods are defined in Directive 89/108/EEC (on quick-frozen foodstuffs). This includes, for example, the freezing, packaging, labelling and inspection of frozen foodstuffs. In particular, it is regulated that the temperature of frozen foodstuffs must be maintained at -18 °C or lower at all points of the product.
The aim is to avoid health hazards for consumers in the
food production and preparation. The international Good Manufacturing Practice (GMP) and the Good Hygiene Practice (GHP) are preventive concepts for measures that serve to avoid a health hazard during production, processing and sale up to hygiene in the commercial kitchen. The GHP forms the basis for the HACCP concept. The HACCP concept is a system for hazard analysis and risk control for the entire production process of a food product.
Temperature-controlled food logistics includes the transport and logistics of foodstuffs at arctic temperatures around -18 °C to spring-like plus degrees. For example, fish, fish preparations (frozen or deep-frozen) must be transported at -18 °C - butter at + 10 °C, meat at + 6 °C, minced meat + 2 °C and pasteurised milk, fresh dairy products (yoghurt, cream, fresh cheese) at + 6 °C. Depending on the outside temperature (winter, summer), transport vehicles in logistics must have the option of heating or cooling. Different transport vehicles are used for this: refrigerated trailers with different cooling zones, tankers or insulated box bodies. All vehicles in logistics are subject to constant temperature control and documentation.
Foodstuffs are stored in very different warehouses, at different temperatures and under different storage conditions. In warehouses for frozen food (TiKo or TK warehouses), foodstuffs are usually cooled down to -20 to -24°C. Sometimes there are also "blast freezer" areas down to -35°C. The top priority is that the cold chain must not be interrupted. In dairy products (mopro) or fresh fruit and vegetable storage, the temperature is usually +2 to +8°C and possibly increased humidity. There are particularly high requirements for cleanliness here. There are different temperatures in the frozen, defrosted and meat cold stores. In the cold storage room -1 to +2 °C are prescribed, in the defrosting area < 10 °C (2-15 °C with air flow) and in the freezing rooms at least -18 °C. The temperature requirements (maximum temperature) for food of animal origin subject to refrigeration, which is supplied loose or self-packed, are as follows: fresh meat (except poultry) +7 °C, poultry products +4 °C, offal, fresh (also ground) +3 °C, meat preparations from EU-approved establishments (self-service packed) +4 °C. In general, the permanent monitoring of storage and processing temperatures as well as the high hygiene standards ensure perfect quality. The temperature in a chocolate warehouse is between 12°C and 20°C (mostly 18°C). Chocolate is sensitive to moisture, oxidation, heat, temperature fluctuations and odours. If chocolate is stored in a well-sealed container and a suitable room, it has a very long shelf life of at least one to two years. Dry goods are all articles that can be preserved (dried fruits, spices) or have been preserved (preserves). These articles usually do not require refrigeration. Warehouses for chocolate and dry assortment are mostly like conventional warehouses. The items are usually pre-packed and stored and handled on Euro pallets.
Each storage area has its own challenges in terms of temperature, humidity, sensitivity of the goods, etc.. This results, for example, in influences on the working conditions of the employees, choice of storage technology and requirements for cleanliness. Due to the cold and adverse working conditions, various solutions are being tested to increase the degree of automation.
One speaks of an active cold chain in logistics when the goods are subject to continuous cooling, temperature control and recording and the corresponding vehicles and warehouses are equipped with cooling technology. In the passive cold chain, the temperature is kept within a certain range through the use of insulating packaging. Temperature control is not necessarily mandatory. Temperature maintenance can be additionally supported by dry ice, for example. The passive cold chain is mostly used in logistics on the way to the end consumer ("last mile"). To maintain quality when storing food, five principles must be followed. First and foremost, the refrigeration temperature must be controlled without interruption so that an active cold chain is maintained without interruption. Only through strict control of incoming and outgoing goods can quality be assured. Unpackaged or raw food must be stored separately. In general, only dedicated storage containers may be used to protect against germs. Goods must not have direct contact with the floor.
Cleaning and disinfection in areas where food is handled and processed is subject to special regulations. The objective of cleaning and disinfection measures is clearly formulated in Regulation (EC) No. 852/2004: Consumer goods, i.e. all objects and surfaces that are intended to come into direct or indirect contact with food, must be cleaned and, if necessary, disinfected so often that there is no risk to the food. This is to ensure food hygiene and hygiene in general in the company. The Federal Food Hygiene Ordinance (LMHV) also refers in Annex 1 to required expertise in food hygiene when training employees. Point 10 deals with cleaning and disinfection.
Wet cleaning is not allowed in a deep-freeze warehouse. Therefore, cleaning must be done with a broom. In the case of pallet flow racks, care should be taken to ensure that the floor level can be folded up or that there are other cleaning concepts. The "breakage" of goods must be prevented at all costs, as burst bags of e.g. frozen fruit can produce veritable "projectiles". A scenario: a forklift wheel drives over a frozen cherry, which then shoots through the warehouse like a bullet!
The products Mopro and fresh food stores (dairy products, fruit, vegetables, etc.) can be perishable on the one hand, but on the other hand they are often contaminated with dirt. Tomatoes and lettuce packed in trays or crates sometimes still contain sand and soil. This can fall out. In addition, yoghurt pots can burst open. Because of this, the demand on the cleanability of the storage area is high. Therefore, low storage or block storage is usually used in these cold stores. Drainage channels in the floor can simplify cleaning by spraying or flooding. Shelves must then always be levelled and brought into plumb.
According to QS Qualität und Sicherheit GmbH, which organises the Quality Assurance System 2001 (QS System 2001) in the meat sector, "Premises in which food is handled and rooms in which food is stored, prepared, treated or processed must be kept clean and in good repair at all times in accordance with Regulation (EC) No. 852/2004 Annex II. They must be laid out, designed, constructed and dimensioned to allow adequate cleaning and/or disinfection, to avoid or minimise aerogenic contamination and to provide sufficient work surfaces to allow hygienic operations. Rooms in which food is stored, prepared, handled or processed must be designed and laid out to ensure good food hygiene and to prevent contamination between and during operations." Frequently, meat production is already filled into end consumer packaging, which then subsequently acts as hygiene protection. According to the Guide to Processing Meat and Meat Products (2), "Surfaces (including surfaces of equipment) in food handling areas, and in particular food contact surfaces, shall be maintained in a sound condition and shall be easy to clean and, if necessary, to disinfect. They must be made of smooth, abrasion-resistant, corrosion-resistant and non-toxic material."
Warehouses for chocolate and dry assortment are mostly like conventional warehouses. The goods are usually pre-packed and stored and traded on Euro pallets.
According to the Federal Office of Consumer Protection and Food Safety, "the minimum durability date or best-before date is the date until which a packaged foodstuff can at least be stored and consumed while retaining its specific properties. Odour, taste, texture, nutritional value, colour and consistency must remain unchanged until the expiry date. If the correct storage conditions are observed in each case, for example cool or dry storage, food can often be stored and consumed beyond this date."
In commercial food storage, maintaining the correct delivery sequence (First In - First Out, FIFO) for the best-before date (BBD) is crucial to keeping food shrinkage as low as possible. Flow racks (unit load and pallet flow racks) are particularly suitable here. The flow rack system is filled with goods on one side, which are later removed on the other side. The FIFO principle facilitates the monitoring of expiry dates, batches or production series. The FIFO principle can also be ensured, for example, by a shuttle rack storage system.
When transporting food, the transport time plays a major role. Food is increasingly ordered online from e-commerce or e-grocery companies. On the last mile, a short delivery time is particularly crucial. Innovative packaging solutions for refrigerated transport, especially with passive cooling, are in demand here, opening up new possibilities for the distribution and storage of goods. This packaging is particularly advantageous if the customer is not at home at the time of delivery. Even without active cooling, it is possible to maintain the required temperature range along the entire cold chain in logistics for up to 48 hours.
A perfect container system for the food trade and e-commerce (e-grocery), especially on the last mile, is the MB Food & Delivery box from BITO. The system consists of container variants, modular insulating inserts, cold packs and bottom dividers. It can be used to transport many different types of food in a space-saving way. The container is available in many different configurations. For example, different insulating inserts made of expandable polypropylene (EPP) allow it to be used in different dry or refrigerated areas. As the inserts are available in different sizes, one box can also be equipped for two different fresh and temperature zones. The correct cooling temperature is maintained by means of high or semi-high cooling packs.
1 Die Tiefkühlkette, Empfehlungen zur Temperatursicherung, Arbeitsgemeinschaft Kälteforum dti/VDKL Deutsches Tiefkühlinstitut e.V. (Berlin) und Verband Deutscher Kühlhäuser & Kühllogistikunternehmen e.V. (Bonn)
2 Leitfaden Verarbeitung Fleisch und Fleischwaren, Qualitätssicherung vom Landwirt bis zur Ladentheke, Stand 1.1.2020, QS Qualität und Sicherheit GmbH (Bonn)
Nitsche Benjamin, Anna Figiel, Zukunfttrends der Lebensmittellogistik -Herausforderungen und Lösungsimpulse, Hrsg. Straube Frank, Universitätsverlag der TU Berlin, 2016, http://verlag.tu-berlin.de