Two outbreaks in three years of salmonellosis involving California almonds have put the state's No. 1 agricultural export on notice that constant vigilance by growers, huller/shellers, and handlers is necessary to continue to provide a safe and healthful product.
Even if a handler pasteurizes almonds, their growers still have a responsibility to protect the crop from on-farm sources of microbial contamination, according to Merle Jacobs, associate director of industry relations for the Almond Board of California. Salmonella bacteria are known to be present at very low levels throughout production areas in California, Jacobs says, but following good agricultural practices (GAPs) is the key to reducing the risk of contaminating the crop.
“If a handler receives almonds from growers or hullers and shellers who did not practice GAPs and GMPs (good manufacturing practices), a pasteurization process that provides a five-log reduction of bacteria such as Salmonella may not be sufficient to eliminate all contamination,” says Linda Harris, Cooperative Extension specialist in microbial food safety, Department of Food Science and Technology, UC-Davis.
Harris explains that a five-log reduction means the treatment will theoretically reduce Salmonella (if present) by a factor of 100,000. This is considered an appropriate level of reduction for almonds.
“The targeted reduction that processors use (five-log reduction) is based on an assumed maximum load of Salmonella, and not a higher load,” Harris says. “This is why it is important that nuts coming into a processing facility be as free from Salmonella as possible.”
Farm manager Ken Ballou, Vetsch Farms of California, an almond producer in the Wasco-Delano-McFarland area of Kern County, Calif., says he considers the orchard the “weakest link” in the chain from producer to consumer in terms of preventing microbial contamination. Even though he finds following GAPs an additional challenge in an already heavy schedule, he says that “at Vetsch Farms we feel we have to take responsibility for our role in providing a safe product. GAPs can be demanding, but it is important to do what we can proactively to ensure that the almond product we deliver is the highest quality.”
The Almond Board has developed GAPs for almond growers that target the four main sources of on-farm contamination. They are:
Poor quality water, or poor moisture management that favors microbial growth.
Manure as fertilizer, while not recommended by the Almond Board, should be properly composted if used.
Fecal material from wild animals and livestock or pets.
Poor human hygiene practices.
Water at harvest
“It's difficult to control environmental factors, such as moisture,” Ballou says. “To me, a critical source of potential microbial contamination is moist nuts on the ground during harvest. It starts with growers not monitoring moisture, and not allowing nuts to adequately dry on the ground. A few years ago we started hedging our trees to allow sun and air circulation to dry the nuts. We now have four feet of open space between rows and the trees have responded well.
“It's also important to manage irrigation during harvest,” he adds. “We keep water pressure high enough so the tree has some water, but we are not getting the nuts wet. While we usually irrigate a 15-foot-diameter area under the tree with fan jets set at 20 psi, we reduce this at harvest to 8-10 pounds of pressure.”
Vetsch Farms is focused on nut quality, according to Ballou. After securing tree health and implementing an integrated pest management program when he arrived at Vetsch five years ago, Ballou turned his attention to adopting the GAPs “one at a time,” he says. “We have been following GAPs earnestly for three years. Joyce Lett, our office administrator, receives all the documents from the Almond Board and passes along a summary to me,” Ballou says. “She keeps me informed about orchard sanitation and all the precautions we need to take to follow GAPs, which are very important to us. My understanding of GAPs has quadrupled in the past six to 12 months, when we've received the bulk of information, and we've been more focused on it.
“If there is another incident and almonds develop a bad name, we will all suffer,” Ballou warns. “The Almond Board is representing us well, and keeping us informed on health issues.”
At Air-Way Farms in Fresno County, GAPs are also part of the management program. Troy Lyles, director of farming operations, oversees the four ranches located from Five Points to south of Huron.
Avoid another recall
“Many GAPs are common sense practices we were doing anyway,” he says. “If growers are not following them, they should be. GAPs will help reduce the potential for another recall; we need to follow them as closely as possible so we don't bring anything into the processing facilities,” he says.
The GAPs that address fertilizer sources “are important to follow,” Lyles says. “We do not use compost in the orchard because of the risk it brings,” he emphasizes. “It is a possible source of contamination if it is not allowed to heat properly and is not rotated, and we don't want to take that risk.”
For crews working in the orchards Lyles makes sure portable restrooms and washing facilities are nearby. “We have them throughout the ranch and tractor drivers and irrigators never have to go more than one mile away.”
Training and documentation are two critical areas covered by GAPs. Lyles includes GAP training at his regular worker safety and pesticide safety training sessions. He takes training a step further by having annual meetings with the crews to explain why management is following GAPs. “My assistant and I meet with each crew to be sure they not only know how to carry out GAPs, but also to understand why we are doing them.”
Documentation includes maintaining readily accessible records of all farm operations, such as farm history, diagram of the orchard layout, diagrams of adjacent land use, crop management flow charts, worker training programs and evidence of training, placement and servicing of sanitary facilities, water sources, water testing plans and results, fertility management operations, and orchard floor management, which is particularly critical before and during harvest.
Air-Way almonds are delivered to their handler, Harris-Woolf Almonds, in company-owned bottom-dump trucks. At the start of the season, Lyles explains, drivers inspect the trucks and trailers, and clean and sanitize them before transporting almonds.
As their almonds arrive at Harris-Woolf, they are sampled for possible contamination, and almonds from each variety in each block are assigned a lot number. This documentation provides for trace-back of nuts in the event of a recall.
“Trace-back narrows the potential sources of contamination so that an investigation may identify areas where GAPs or GMPs are not being followed,” explains the Almond Board's Jacobs. “It also minimizes the amount of almonds recalled to a particular lot number instead of the entire supply.”
Overall, handlers are now being more diligent in tracking almonds by lots, and keeping accurate records of lot numbers so that any problems can be traced back to the grower, according to Jacobs. In the event of a recall, this is the information that regulators will require in order to determine the source of the problem. Another recall will not only hurt the handler involved, but also the huller, sheller, grower, and the entire almond industry. For this reason, GAPs are more important than ever. Most growers are already following many of the GAPs, and others can be phased in one at a time.
Growers should not be “intimidated into inaction,” by the size and scope of the GAP's, Jacobs advises.
The GAP and related documents are available online at the Almond Board Web site: www.AlmondBoard.com, under the Food Quality and Safety heading, or by calling the board at (209) 549-8262.