August 1, 2014 | Laurie Gorton

Like all food processors, bakers and snack manufacturers must deal with pests of all sorts if they want to prepare their products in food-safe fashion. There are those with two wings or four legs, and then there the ones with six, eight or a hundred legs. None are the size of Godzilla, but often they seem just as hard to keep out of the plant.

Pest control tops the list of infractions found by U.S. Food and Drug Administration (FDA) inspectors, according to Chengboey Lau, principal scientist for regulatory compliance/food safety at Mondelez International, Deerfield, Illinois, U.S. She spoke at the May 2014 technical conference of the Biscuit & Cracker Manufacturers’ Association. Reviewing FDA’s database of Form 843 incident reports filed by inspectors during 2013, she found, “(Of) the key areas they’re looking at, the top three frequencies are pest control, sanitation and hand washing.”

The pressure comes from not only regulators but also customers. Hazard analysis critical control points programs encompassed pest control from their inception. It has been included in the Global Food Safety Initiative and its voluntary standards from their start, and it will be part of regulations that implement the Food Safety Modernization Act through mandatory preventive controls.

Such heightened awareness increases the need to monitor stored food ingredients and finished products. “Pest control is a key part of everything,” said Mel Whitson, regional manager and degreed entomologist, Central Life Sciences, Palm Bay, Florida, U.S. “It requires you to manage every aspect of your operation: who you’re buying from, how it’s processed by the supplier, how you’re receiving it, how you’re storing it, how you’re using it at your facility and how the plant is managed and sanitized.”

While birds and rodents pose their own set of problems, it’s the bugs that concern this article. “Such pests open the path for other scavengers,” Whitson said. “Once the food is compromised, more pests attack. The infestation feeds itself.”

The types of pests have not changed in recent years, observed Zia Siddiqi, PhD, director of quality systems, Orkin, a subsidiary of Rollins, Inc., Atlanta, Georgia, U.S., but emerging food types have added to risks. “The trend toward organic or natural products, in fact, has been more favorable for the stored-product insect pests,” he said.

Materials at peril

Stored materials can be any food item in the plant, from raw ingredients to finished packaged products. Some are prone to attracting bugs, and some not.

“In the snack area, raw potatoes don’t present much concern,” Whitson said. “There’s not much that attacks them after harvest. They are inherently pest-free because Mother Nature designed tubers to spend time in the ground and gave them defenses.”

But it’s different for corn, wheat and all grains. “Grain-based materials have carbohydrates and proteins, which insects like,” said Raj Hulasare, PhD, PEng (Canada), senior scientist and product manager, Temp Air, Inc., Burnsville, Minnesota, U.S.

The type of stored material makes the difference. “If the facility accepts grains and processed grains, it’s at risk of attracting a wide variety of pests,” Whitson said. While not many bakeries store raw grains to later mill and bake on the same site, they do receive flour, graham cracker crumbs and other such ingredients.

Siddiqi added spices, nuts, candy pieces and dried fruits to the list. “All pests, including stored-product pests like Indianmeal moths and cigarette and flour beetles, need food as well as moisture to survive, which make any food processing facility a target,” he said.

Finished products, too, require protection. Hulasare strongly recommended use of modified atmosphere packaging that cuts oxygen levels inside the package to less than 2%. Another anti-pest tactic is insect-resistant packaging materials. “Such tools ensure that the clean, uninfested packaged product stays free of insects during transportation and in the retail environment,” he observed.

Balance of responsibilities

Flour millers and other grain processors are well informed about stored-product insect pests, but such problems in bakeries are not well-researched. “There isn’t a lot of published information on insect-related problems in bakeries and snack facilities, but the facility managers and the pest management service providers know the type of problems encountered,” Hulasare said. “The risk of infestation varies with the type of food product stored, duration of storage and level of sanitation and pest management practiced by bakeries and snack facilities.”

Many bakers and snack manufacturers prefer to work with professional pest management services because of the specialized knowledge required for safe and effective action. “We view pest management as a partnership between provider and manager,” Siddiqi said, “and it’s a trend that more and more food processing facilities are following.

“There are several responsibilities a plant operator has even when a pest control service is in place,” he continued. Working together, the partners can devise an integrated pest management (IPM) program that helps plant operators plan ahead with proactive techniques to prevent pest infestations before they happen. These non-chemical approaches include sanitation, housekeeping and building management issues. “IPM relies on chemical applications only as a last resort and then only in targeted areas,” he added.

Such preventive measures are backed up with curative methods, “because it would be impossible to know where the pests are hiding in a large food facility,” Dr. Hulasare noted. “The scope of services for the pest management service provider should be dictated by the food facility managers based on need and corporate policies. Some companies prefer to not use toxic chemicals and prefer environmentally friendly technologies.”

Hulasare described heat treatment as one of those technologies. Based on research done at Kansas State University in the late 1990s, Temp Air’s patented method involves positively pressurizing the space to be heated with forced hot air at a minimum temperature of 120 degrees F. This is hot enough to be lethal to all insect life stages, including eggs.

Pheromone traps also fit the friendly category. The traps synthetically mimic the chemical secretions insects use to communicate, Siddiqi explained. “These traps will collect stored-product pests and can help evaluate pest activity and determine the timing for treatment,” he said.

Sanitation and maintenance of equipment can be made more effective by coordinating these activities with the pest management service, Whitson suggested. “When machines are being broken down for thorough cleaning of bearings and other components, they can be inspected and treated at the same time,” he said.

There are good reasons to work together. “Everyone needs to be on the same page — the plant operator and the inspection service,” Whitson said.

Rules of engagement

Getting down to nuts and bolts, bakery operators should take proactive steps to keep bugs out of stored materials. Good sanitation and housekeeping practices pay off big, according to Siddiqi. “Regularly taking out the trash — and keeping trash and recycle bins lined and sealed — can go a long way to limiting attractants to pests,” he said.

Food plant managers and employees should be inspecting their facilities between visits from the pest management service, Siddiqi continued. Any pest activity should be reported, and if possible, they should be caught and provided to the service for identification. The staff should also look around the building’s exterior for cracks and small openings that could allow entry and examine interior hot spots like drains, break rooms and restrooms — “Anywhere pests can find food, water and harborage,” he said.

Hulasare estimated that 90% of pest management is a matter of regularly scheduled sanitation inside — and outside — the plant.

Cleaning underneath, around and on top of conveyor belts, fixed equipment, bins and hoppers is essential. Regular monitoring of storage conditions, eliminating sources of moisture and keeping storage areas cool and well-ventilated will reduce chances of the product becoming vulnerable to pests. Siddiqi recommended keeping storage areas below 65 degrees F because most stored-product pests can’t thrive in cooler temperatures.

But efforts really count when managing received supplies.

Signs of infestation on incoming supplies include webbing, damaged ingredients or packaging, visible insect larvae or insects themselves. “If you see signs of stored-product pests, refuse to accept the shipment and notify your supplier immediately,” Siddiqi said. “Request a supplier inspection, including the mode of transportation.” And don’t forget to report such episodes to the pest management service, he added.

He recommended storage techniques that keep foods away from walls and at least 6 inches off the floor.

When receiving pallet loads, it can be possible for a bag in the interior of the stack to rupture. “This exposes the product to pests,” Whitson said. “It also drops flour or crumbs at the foot of the storage rack in areas that may not be readily accessible for cleaning.”

Whitson offered another tip. “You should be selecting the right-sized package so that you go through it quickly,” he said. “The bigger the package, the easier it is to inspect and maintain in pest-free condition.”

Nothing raises the alarm faster than a contaminated foodstuff. “I’ve seen situations where the pest appears in the packaged food,” Whitson related. A fly that a shopper reports finding inside a bread bag has to get through four air curtains and more than a dozen light traps to reach the packaging area. “You have to go back and look at every possibility that might have allowed that pest in,” he advised. “You have to look at the whole program.”

Species spotted

While the kinds of pests that attack stored foods have not differed over the years, some are becoming more prevalent.

“These pests have been around a long time and haven’t changed much,” said Mel Whitson, regional manager and degreed entomologist, Central Life Sciences; however, some invasive ant species are now showing up in California and Florida. “While these are aggressive species, they are usually considered secondary pests,” he said.

Far more destructive are the insects that break through the tough hulls of cereal grains and expose the interior to moisture, mold and fungus. In some parts of the world, grain and rice weevils damage up to 40% of the crop.

The insects found in bakeries are usually beetles — the red and confused flour beetles — and the Indianmeal moth, which is very common in grain stores and retail environments, noted Raj Hulasare, PhD, PEng (Canada), senior scientist and product manager, Temp Air, Inc. “In snack food facilities, the species varies according to the type of food stored and processed, with flour, cigarette and warehouse beetles the most common.”

Stored-product pests are not like rodents and flies because they are not heavily affected by the weather, said Zia Siddiqi, PhD, director of quality systems, Orkin, a subsidiary of Rollins, Inc. “Stored-product pests also don’t usually pressure facilities from the outside. Instead, they often hitch a ride into a facility on shipments from suppliers,” he said.