Production Tech: Grinding along
E. coli may be the most common pathogen that can be spread at this point in the process, according to Alan G. Miller, president of South Easton, Mass.-based Risco USA Corp.
“In the old days when my father was a butcher, a piece of beef that did not look so fresh was simply washed, removing the bacteria,” he says. “Today’s processing often injects or tenderizes the product, taking what used to be on the outside only, to the inside of the product, where it cannot be washed off.”
Grinders do exactly this, breaking down muscle layers and mixing them together, essentially bringing the outside inside.
“All foodborne pathogens create problems,” says Jerry Knipmeyer, worldwide applications specialist for Marlen of Hutchison, Kan. “Those pathogens which readily multiply at temperatures between 40 and 140 degrees are of great concern since most meat items are generally processed at temperatures between 32 and 40 degrees, and cooked at different temperatures and time intervals. Heat rise during processing is of concern to everyone as well as the ability to maintain sanitary conditions during the process operation.”
The basicsThe first step in ensuring food safety is one of the most basic: maintaining the equipment. That and proper construction are two of the biggest issues with food safety for stuffers and grinders, says Mark Henry, vice president of Bradley, Calif.-based Henry and Sons Inc. With equipment that is not assembled well or badly maintained, seams or metal edges can capture meat and create an environment for bacteria to grow.
The materials can make a difference in maintaining food safety. With grinders, in order to get a longer operational life on plates and knives, for example, they tend to be made of hardened non-stainless material, Miller says. This in itself is not a problem as long as the equipment is handled correctly. If the pieces are not blown dry and oiled after cleaning, they can quickly rust and pit, leaving an area for pathogens to take hold.
Weiler and Co., of Whitewater, Wis., for one, has taken steps to ensure food safety with the design and materials of its grinders. All if its grinders are made with tinned or stainless steel in U.S. Department of Agriculture-approved designs. Weiler also has taken steps to ensure that heat rise is kept to a minimum.
Weiler's grinders also are designed for easy assembly and disassembly for sanitation purposes. The company’s grinders can also include a bone collector called the Piranha. According to the company, the collector’s new design can remove bone and gristle while still ensuring that a majority of the meat will continue through the machine.
With stuffers, suppliers such as Risco have learned to construct the machine using stainless steel and approved non-metallic materials. This allows the parts to be thoroughly cleaned with a wide range of often corrosive cleaning solutions without the risk of rusting afterwards.
Often the grinders are in line with the stuffer so the potential contamination from the plates and knives occurs just before it enters a casing.
Traditional grinders have a tendency to create heat in the product and this becomes more prevalent as wear to the auger increases, Knipmeyer says. Also, stuffers that use vanes, augers and screws have a tendency to overwork product creating extra heat rise. However, machines can be designed to limit the heat rise. Marlen’s grinders, for example, have a twin-piston system that does not use an auger and avoids the heat rise. It uses a pump to deliver the meat to the knife and plate head of the grinder. Using this design, the company has limited heat rise to less than two degrees.
Knipmeyer continues by saying that Marlen also follows the guidelines of the American Meat Insittute (AMI).
“In the design of all Marlen equipment we follow the recommended guideline set out by AMI on the 10 principles of sanitary design,” he says. “We also train sanitation on the proper cleaning procedures for all our equipment. We have videos and monthly training classes available to any Marlen customer.”
Material choice is important when constructing a grinder or stuffer. Design is also very important, as the machine must be easy to clean correctly, Miller says.
“Take, for example, our RS70 in-line grinder. At the rear of the unit we used two solid bushings instead of bearings like other manufacturers,” he says.
Cleaning upProper sanitation also must take the training of those doing the cleaning as well. “A lot of people overlook who cleans these machines,” says Henry. “You have to consider the source too. You have to realize you’re not going to change that.”
Without the proper training, workers will each find their own way to clean equipment with no consistency. To effectively clean equipment and maintain food safety, it takes more than just spraying with caustic cleansers and water.
Henry believes that the industry should move toward using incentives with employees to encourage them to offer ideas to best clean equipment and contribute to the general operation of a plant.
“If there are people out there, mechanical or cleaning staff, if they see a situation and there’s an incentive for them to take action, to save lives, money or time, let them bring it to the table,” he says.
The safety of those same workers is another consideration for any grinder or stuffer that will be used on the plant floor.
“In the 1970s, I was in England and a major producer had so many machine accidents that they put their grinder and mixers in complete locked safety cages,” says Miller. “Only the trained operator was allowed in the operating zone.”
Modern machines are designed to reduce the risk of injury to the employees operating the equipment. Risco has designed a product pump that can be stopped with a simple safety switch. The switch is placed within arm's reach of any potential pinch points on the machine.
An area of particular danger was at the pump exit, Miller says. In older designs of vane pumps, the vane passes by the exit and can easily result in the loss of a finger. With the design Risco has developed, the vane drops down before the pump exit, removing the possibility of a pinch point and potential injury.
Power upEnergy also has become a concern with the increase of prices for all types of energy.
“On a standalone grinder, strength and horsepower are a necessary evil in order to grind colder and faster,” says Miller. “On stuffers, however, it was easy to reduce energy consumption by going to servo drives.”
These drives only start to use power when the machine is asked to pump, unlike hydraulic machines that had to run their main electrical motors constantly, even when the machine was not pumping, he explains. A new design in controls also allows for the machine to power down automatically if not used for a set period of time, conserving power.
The GD 93-3 inline grinding system from Handtmann Inc.offers another example of specialized drive design that improves on product quality as well as optimizing cost for the operator.
According to the company, product feed and knife rotation are controlled by independent drives on these systems. The cutting profile can thus be calculated to match the individual needs of the product.
On top of all of these considerations, the most basic factors must be kept in mind when selecting a stuffer or grinder.
“No. 1, is it going to do the job the way you want it done,” says Henry.
After that, he says, you have to look at durability. What is the annual parts usage for the equipment, a factor that can add a lot more to the true cost of the equipment. Henry and Sons gives references on parts usage so that customers can find out from real-world use what the maintenance costs are.
Knipmeyer also includes labor savings, formulation savings, casing savings, effective vacuumization of the product, capacities, distinctive clean-cut particle appearance, controllable particle size, reduced overworking of product and smear are all aspects processors should consider when purchasing grinders and stuffers.