How technology can outsmart microorganisms to secure safe foods for all

Many of us take the safety of our foods for granted, but according to the World Health Organization¹, every year almost 1 in 10 people globally – that’s an estimated 600 million individuals – will become ill after eating contaminated food, resulting in a staggering 420 000 deaths. In fact, unsafe food that contains harmful bacteria, viruses, parasites or chemical contaminants can, over the short- or longer term, cause more than 200 different diseases. Such diseases range from (most commonly) diarrhoea, to meningitis, and even cancer.

Globalization, food chains, and consumer expectations
The industrialization of farming practices to meet the needs to feed a rapidly expanding global population has added to the challenges of maintaining food safety.  Increased travel and other aspects of globalization have also resulted in increased consumer demand for increasingly diverse types of foods. This then creates long food supply and transport chains that span multiple borders, putting additional pressure on efforts to ensure food safety from farm to fork. 

We can all take responsibility for food safety
Food can become contaminated at any time during handling, processing or transportation. Manufacturing intermediates and final products from complex recipes that include different raw materials and ingredients may involve multiple stages of processing and transportation between factories, before transfer of the finished, packaged products to consumer outlets such as shops and restaurants, and to our homes, all of which also represent potential sources of contamination. As WHO further noted, while the primary responsibility for prevent contamination lies with food producers, everyone can contribute to making food safe, and “good collaboration between governments, producers and consumers helps to ensure food safety.”

Microbiological control
From an industrial perspective, ensuring safety when manufacturing products such as dairy and food ingredient powders is largely about microbiological control. It’s essential that manufacturers comply with strict regulations and guidelines for safe food handling and processing, to help prevent contamination of products by microorganisms, or other physical contaminants that might make us ill, or that might affect product characteristics and properties such as taste, consistency, or shelf life. 

Hygienic equipment and smart solutions
Experts here at GEA have spent decades working to design and configure hygienic components, equipment and smart technologies that can help to minimize the risk of contamination during critical stages in dairy powder processing and handling. From heating systems that rapidly increase the temperature to above those at which bacteria are most likely to thrive, to specialist services that monitor and advise on safe plant operation, our products and knowhow are helping our dairy powder customers around the world ensure that their processes result in high quality, safe and nutritious foods for everyone.

Manufacturing infant or adult nutritional formula powders, for example, will involve multiple process stages – shown below – and so also multiple risk points for potential contamination. 

Example of GEA nutritional formula process line

Hygienic, modern plant design and thorough, automated cleaning-in-place (CIP) systems are important to help prevent contamination by microorganisms at any stage. At GEA we have also pioneered the development of innovative concepts for process safety that can further help to minimize the risk of contamination at some of the most common danger points in processing.

Temperature matters
Evaporation, for example, is a stage in dairy powder processing during which the liquid product is concentrated by removing water, to increase the solids content. It is commonly carried out before product storage or transfer to a spray dryer. The evaporation process will typically involve a pretreatment heating step, followed by heat treatment, evaporation, separation and then posttreatment stages. But while high heat kills bacteria, lower levels of heat can support the growth of harmful, or product-spoiling bacteria. In plate heat exchanging systems that are used today in dairy evaporators there may be zones that hold the right temperature to support bacterial growth and spore formation. And these spores may survive subsequent pasteurization. 

Avoiding direct contact
To avoid this potential risk for bacterial colonization GEA has developed a direct contact preheating (DCP) system that rapidly increases the temperature to above those temperature ranges that are most likely to support the growth of different types of microbe, and the formation of bacterial spores. GEA systems are also designed to minimize as far as possible contact between product and surfaces, which further reduces the risk of biofilm development and microbial growth. Using our direct contact preheating systems, for example, there is no product-surface contact at all during the heating stage, so the risk of microbial growth in problematic temperature ranges should be minimal. 

Direct steam injection
We have also developed and offer a range of pasteurization and high-temperature heating solutions that can be configured to give producers the best options to suit their processes and products, as well as help to minimize contamination risk. For example, our tangential swirl heater technology heats the product using steam that is injected directly into the liquid. Direct steam injection results in rapid, consistent heating without scorching the product, and also means that there are no surfaces upon which bacterial growth might be supported. 

Hands off
Any point in a process that involves manually disassembling and reassembling equipment for cleaning or inspection can be considered a risk for introducing contamination. GEA has also worked to develop solutions that can increase safety, by reducing manual tasks. Our No Intervention Fines Return System (FRS) for food and dairy spray dryers uses patented valves, which effectively eliminate the need for manual configuration at points before and after cleaning-in-place (CIP) that could otherwise represent a risk for leakage and contamination. 

GEA No Intervention Fines Return System
GEA experts have also developed what we think is a groundbreaking innovation, in the form of removable insulation panels for spray dryers, which make it easier to thoroughly inspect the spray dryer chamber for tiny cracks that might harbor bacteria and other microorganisms. The widespread uptake of this GEA technology demonstrates just how valuable it is for helping to ensure microbiological safety in food and dairy spray drying plants. 

Getting physical
GEA offers state-of-the-art separation systems that physically remove bacteria, spores and other contaminants from products, and which are routinely used during dairy powder processing. Our centrifugation systems harness gravity to sediment out bacteria and spores, while GEA ceramic microfiltration equipment separate out microorganisms and other contaminants according to size, through specially designed filters.

Centrifugation and ceramic microfiltration are ideally suited to milk processing for removing microorganisms - including heat-resistant bacteria and spores – which can survive pasteurization.  Configuring these mechanical technologies into the process can eliminate the need for high heat treatment, and so help to maintain the product’s nutritional value.

Robotics and automation
Elsewhere in the plant, robotic systems upstream and downstream of product processing can negate the need for manual handling and intervention when receiving raw materials and ingredients, and again at the filling and packaging stage. In many industrial processes bags of powder must be manually lifted and manoeuvred, and then opened by slitting with a knife to remove the powder. The potential issues associated with this method, with respect to both operator safety, and to potential powder contamination, can be significant. To reduce these risks GEA has developed the automated, robotic HYGiTip bag slitting and emptying system which takes the place of the human operator to carry out this function.  

GEA HYGiTip bag emptying system
For bag filling at the packing stage, our limited intervention (LI) powder filling technology has been developed to fully automate bag handling throughout the entire bag filling and closing process. Using the LI system means that operators are unable to touch the bags during filling, which again reduces the risk of product contamination. For filling small volumes we’ve developed the SmartFil M1 semi-automated powder filling system, which can be configured with a sealed filing head to help prevent product contamination, as well as support operator safety. 

Microbiological expertise
GEA safety systems are designed to fit in with our customers’ processes to help support food safety, efficiency and reproducibility. We work with each customer to tailor the best safety solutions for their processes and products. Importantly, we consider the whole process, from end to end, so that every part of production can be addressed in terms of food safety. Our in house microbiology experts work together with technical experts to define the best solutions for customers on a case-per-case basis.

Specialist, dedicated services
Our partnership with customers doesn’t end once GEA systems have been installed. We have developed GEA SAFEXPERT® as a suite of diagnostic and consultancy services that gives customers complete oversight of all of their processes, to help monitor and optimize production, and in particular to support food safety, every day.

Through the GEA SAFEXPERT® service customers get a complete, 360 degree health check and report on their plants with recommendations for maintenance and CIP optimization that will help to prevent contamination. The GEA SAFEXPERT® environmental microbial monitoring, and validation services can also help to diagnose the cause of any existing contamination, and suggest approaches for elimination, and for preventing contamination in the future. 

1. Food Safety (who.int)