By Neil Giles, Marketing Communications Manager, Mettler-Toledo Product Inspection
According to the Food and Agricultural Organisation of the United Nations, up to 95 per cent of customer complaints are related to contamination of food by physical, chemical or biological sources. This makes the inspection of food products at all stages of the supply chain vital, not only for health and safety reasons, but also to reduce the substantial expense of having to reject large batches of food.
Raw ingredients supplied to manufacturers by farmers and growers are particularly at risk of contaminants such as bone splinters, bolts from machinery, stones and barbed wire. Staff trained in quality assurance will pick up the larger unwanted items with constant visual checks, but for contaminants that are too small for the human eye, or are hidden from sight – cows have been known to eat barbed wire for instance – more sophisticated levels of contaminant detection are required further down the supply chain. Ultimately, it is the bulk food handlers and food processors who have to comply with strict food safety regulations, and it is vital that they identify the points at which contamination is likely to occur and implement effective detection systems at those points.
Contamination during the manufacturing process is also a real possibility and there have always been food safety issues around traceability, threats and vulnerability to the consumer. In order to conform to food safety standards, especially for manufacturers supplying major retailers and supermarkets, a number of standards and regulations are in place. These include the British Retail Consortium (BRC) Global Standard for Food Safety, the International Feature Standard (IFS) and the Food Safety System Certification 22000 (FSSC 22000). A recent overhaul of food safety standards in the US has bought the Food Safety Modernization Act (FSMA) to the fore. All of these bodies are constantly evaluating and refining their respective standards in order to raise food safety standards. The need to comply with any one of these standards makes effective product inspection equipment vital.
In order to maximise product safety and to make the most effective use of inspection systems, identification of Critical Control Points (CCPs) is essential. A CCP is a point at which control must be applied to reduce the risk of contamination. Where these are placed depends on many factors, including type of production line, the potential threat posed by the contaminant, cost effectiveness and practicality.
The most common location for x-ray inspection systems is at the end of the line, after packaging and sealing. Contamination can happen at any point in the production process right through to the points where the final package is sealed. End of line inspection can also incorporate other quality control checks, such as checking for over- or under-fills, detecting damaged, broken or misshapen packaging and counting components, such as instruction leaflets or free gifts in cereals.
However, by having the inspection system at the end of the line, when all the value has been added to the product, rejecting contaminated products can prove costly. Early detection of contaminants reduces waste and prevents the finished product being rejected after it has received maximum added value. Each processing step can introduce new contaminants, and every new step is likely to break existing contaminants down into smaller, less detectable pieces, making contaminant inspection both easier and more efficient earlier in the process. Indeed, a common location for pumped products is at the start of the production process, when product value is low and the risk of contamination from incoming raw ingredients is at its highest.
The right tool for the job
Most pipeline product inspection systems are specifically designed for a variety of applications at all stages of production before final packaging:
Metal detection technology identifies ferrous and non-ferrous metals plus stainless steel contaminants from food products in liquid, paste and slurry forms, for example beverages, soups, preserves, baby foods etc. Product flows through an electro-magnetic field, which remains undisturbed unless a metallic object passes through it – at which point the source is identified and rejected from the line.
X-ray systems capture a greyscale image of the product, which the internal software then analyses and compares to a predetermined acceptance standard. Based on this comparison, the product is either accepted or rejected. To be detectable by x-ray inspection, the contaminants must be denser than the product in which it has become embedded. The contaminant will absorb more x-rays than the surrounding product and will therefore be visible on the image created.
Both technologies have considerable merit, but which one you choose should be determined once you have accurately identified the type of contaminant you are likely to encounter.
Effective Removal of Physical Contaminants
Detection equipment for pumped products is advancing and inspection technology is known to improve Overall Equipment Effectiveness (OEE). Piped food products can be contaminated by fragments such as calcified bone, mineral stone, glass shards and metal filings, and while manufacturers need a technology to identify these elements, they also need the ability to ensure the precise removal of the contaminated product with minimal product waste in order to reduce costs.
In both metal detection and x-ray systems, internal software sends a message to an automatic reject system/valve, which removes the contaminated product from the production line. This same signal is also able to stop the production process altogether by deactivating the line if this is preferred. For pumped liquids, slurries and pastes a sanitary three-way valve can operate on detection of foreign bodies and divert the contaminated product away from the line.
Data management software further enhances food safety by helping manufacturers ensure compliance with increasingly rigorous industry regulations. Real-time remote access to data from a range of product inspection technologies, including checkweighers, metal detectors and x-ray inspection systems makes the process more efficient and helps to reduce downtime during product changeovers and machine maintenance, as well as minimising manufacturing costs. With the right equipment, operatives can undertake real-time corrective action for optimum processing line efficiency through an intuitive on-screen user interface. Manufacturers can track their products through information relating to product rejects and machine performance from all their networked inspection systems. The user interface provides early warning of adverse product quality and machine performance to prevent product safety issues before they become a problem.
Retailers put their full trust in the various entities involved in the food supply chain that safety procedures have been rigorously applied. They trust that the risk of contamination is minimal or zero at the time of a product being placed on the shelf. Identification of the best product inspection technology for the job is key to optimising food safety and quality by successfully removing contaminated food from the production line and therefore the food supply chain. There is no room for error - ultimately it is the product’s brand that will pay the price for substandard food stuffs and consumer health remains, as always, top priority.