Sealing the deal

By Paul Gander

- Last updated on GMT

Related tags: Meat

Sealing the deal
Investing in a packing line because it offers above average hygiene control sounds, on the face of it, like choosing a new car purely on the basis of its fuel-efficiency. In each case, there will probably be other, more pressing priorities. And the assumption is likely to be that manufacturers are constantly improving both these parameters.

Tony Ambrose, UK marketing director at machinery company Marel, spells it out: "The equipment has to operate at a high enough speed and with the right accuracy. Hygiene on its own doesn't count for much." ​Even in a fresh red meat, poultry or sliced meat operation, where food safety is centre-stage, it is unlikely to sell the line. But to push the analogy further, the past few years have seen a range of issues nudge petrol consumption, for many, higher up the list of car-buying priorities. A very different set of issues have had a similar effect on product handling techniques on meat packing lines.

That list stretches from increased concerns about food-borne pathogens, and limits on salt content and other preservatives to the desirability of even incremental extensions to shelf-life and the greater availability of proven alternatives to manual handling.

But it does not stop there. The link between automation and reduced operator involvement cascades down into smaller factory footprints and potentially (through lower temperatures at the packing stage) an even greater impact on shelf-life, Marel argues.

Automation and bacteria

The argument is supported by recent work carried out at the University of Lincoln, where Mike Dudbridge is manager of the National Centre for Food Manufacturing. Using a line supplied by Marel, he examined the likely impact of automation on bacterial load and growth in sliced, ready-to-eat meats (designated 'high risk' by the Food Standards Agency).

Research among manufacturers found that around 1.5% of packs were of unsatisfactory quality by the end of their shelf-life. "By gaining control over an automated process, manufacturers are not only likely to eliminate these 'outliers' but also to be able to set an extended shelf-life thanks to lower start-of-life contamination levels,"​ says Dudbridge.

"The larger retailers are all looking at manufacturing advantage in terms of the quality and shelf-life of their products,"​ he adds. There is also a heavier emphasis on in-store food waste from the Waste and Resources Action Programme (WRAP) and retailers themselves.

So the higher levels of hygiene that come with reduced operator involvement can be an attractive by-product of increased automation, Marel argues. Ambrose adds: "Temperature is a big factor in the growth of bacteria. If you have people working in the same area, it's more of an issue. But if you use robotics, that can help."

Dudbridge at Lincoln quantifies this, pointing out that while hand-packing operations tend to have ambient temperatures of between 10°C and 12°C, fully automated lines could run at a significantly lower 58°C. The temperature on a gloved hand, even in a chilled environment, can be over 20°C, he adds.

"Until the Lincoln study, the link with robotics had never been proven," ​says Ambrose. "At the same time, though, for many products, just one extra day of shelf-life can be worth a fortune."

This is all compelling stuff. But in reality, completely eliminating operator involvement in a line is more problematic. Just over a year ago, Marel installed a slicing and triple-head robot pick-and-place packing line at Grilstad, Norway. "The equipment replaced an old salami line, and has saved them a lot of labour," ​says Ambrose. But the company still requires two people to load and monitor the equipment.

Marel says it has similar installations in the UK slicing, picking and packing bacon and other meat products. "In the UK, though, there's a pronounced ergonomic emphasis behind much investment in robotics,"​ says Ambrose.

Dudbridge believes that more manufacturers now consider that automation can enhance flexibility rather than limiting it. But as he acknowledges, it can be difficult convincing managers that operators should be paid to monitor a line rather than do the job they are monitoring.

Shorter shelf-life products

The hygiene arguments regarding automation can be less convincing still in shorter shelf-life, fresh meat products. Ulrich Nielsen, solutions director at Ishida, says: "On our mincemeat and poultry lines, product takes less than a minute to get from the cutting or mincing station into a sealed pack."​ He is clear that temperature can also make a big difference, but time is the key. While Marel explains how its buffering between slicing and packing can ensure smoother line operation, Ishida is proud of the fact that it does not use buffering at all.

Nielsen says: "The main reason for looking at robotics will still be in order to cut staff numbers. There are other things you can do to extend shelf-life."​ His experience is that the latest robotic systems still make mistakes. "So you still need someone checking the process. I'm very doubtful about the efficiencies of robotics on tray-loading."

Even in the latest "high-end" ​poultry lines that Ishida has developed in conjunction with fellow supplier Meyn, says Nielsen, operators still style chicken portions inside trays. This supplier co-operation can save labour and space in other areas, he says. "Working together with Meyn on the earlier stages of the process, our latest design saves around 40% on the factory footprint, with a requirement for less equipment."

At Sealed Air Cryovac, European fresh protein market manager Jon DeRoeck agrees with Ishida that speed of packing is a primary objective for most meat plants. He specialises in industrial packaging installations, where beef for instance is broken down into primal joints after slaughter.

Once they have been deboned and trimmed, these are loaded into vacuum bags for a maturing process of up to four weeks in the UK. Only later are they cut and packed for retail. "The objective is to get the meat deboned and vacuum packed in as short a time as possible,"​ says DeRoeck. "There is a direct correlation here with the level of cross-contamination and bacterial load, and so with shelf-life." ​He adds: "Where companies reduce the number of people, this may be to make the operation more financially viable. It may also have the effect of reducing the risk of cross-contamination."

While most other types of meat and poultry can be deboned and trimmed automatically, this is not true of beef, says Sealed Air Cryovac. In the vast majority of cases, the bag-loading and shrink operation is in the same hall as the deboning, making it doubly difficult to reduce temperatures and so minimise bacterial activity that way.

Customers can specify a robotic system or a semi-automatic alternative. "Even on the robotic loader, there's an element of human contact,"​ says DeRoeck. "But the chief advantage is that, just after all those new surfaces have been exposed during deboning, the temperature of the product does not have the chance to rise significantly."​ Carcasses are taken from temperatures of between freezing and 2°C in the chill cabinet into the 78°C of the deboning hall. The aim is to keep the time outside the colder temperature to 20 or 25 minutes, he says.

At thermoforming and traysealing supplier Sealpac, marketing manager Marcel Veenstra points out that, while robotic loading could work best for slices, it uses other automatic loading mechanisms for portions of mincemeat.

A Sealpac line at Himmerlandskød in Denmark is automatically portioning mince into 3kg wholesale and 500g retail trays, sealed under modified atmosphere (MAP). So here, fast changeover and quick tooling exchange on the sealing line are high priorities.

There may be many routes to improved food safety, hygiene and shelf-life, in meat and poultry processing and packaging, but automation looks set to play an ever greater role.

Related topics: Meat, poultry & seafood

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