Growing Magazine - August, 2013

COLUMNS

From the Ground Up: Natural Food Safety From Field to Fork

By Tamara Scully


While care and common sense go a long way, products designed to reduce the risk of contamination in the field or postharvest in packinghouses, storage sheds or processing lines provide a second line of defense.
Photo by RoganJosh/morguefile.com.

The Food Safety Modernization Act (FSMA) has brought food safety to the forefront for everyone. Food safety on the farm takes place even before the first seed is planted, and doesn't end until all crops have been picked, packed, processed and consumed. Every aspect of growing food has the potential to cause a food safety concern. From soil amendments to pest populations, irrigation water to cleaning water, and hands to equipment, sanitation practices need to occur to keep produce safe.

While the FSMA offers some exemptions for small growers and does not cover all crops, growing food safely is a concern for every farmer. No matter how large or how basic your farming methods, there are ways to ensure a harvest that is healthy in every aspect, from the farm field to the consumers' dinner plates. A comprehensive sanitation plan can be readily implemented, no matter how short the supply chain.

Growers following natural growing practices, including the USDA's National Organic Program, can find products to assist them in maintaining a safe food supply every step of the way. Agricultural products designed to eliminate pathogens from the field to the table can be naturally derived, safe and effective.

Soil and irrigation

How soil or water contaminants in the field can impact the safety of different produce items isn't well understood. However, it is theorized that pathogens can enter plants in several ways: via the roots, via an injury, or by residing on the plant's surface. Soils with a healthy microbiology are thought to be less hospitable to pathogens. Reducing soil pathogens, eliminating bruised produce, and cleaning the surface of produce are all ways to decrease pathogen risk in the field.

The USDA's Food Safety Research Information Office reports ongoing research studies being conducted on the transference of harmful pathogens present in the soil. This preharvest route of infection can be addressed in part by following guidelines for manure applications and composting, keeping fecal material from all animals - domestic and wild - out of the field, ensuring that water used in field irrigation is pathogen-free, and maintaining healthy soils high in organic matter.



Reducing soil pathogens, eliminating bruised produce, and cleaning the surface of produce are all ways to decrease pathogen risk in the field.
Photo by mensatic/morguefile.com.

There are also crop protectant products designed for preharvest field application. These products are meant to reduce contaminants on fresh produce prior to harvesting, adding another layer of protection to the farm's food safety system. Many fungicides and antimicrobials are designed for preharvest quality and disease control. Reducing potential disease-causing pathogens on produce before harvest decreases the postharvest potential for spoiled produce, as well as field contaminants.

BioSafe Systems offers a preharvest bactericide/fungicide that is designed to reduce the population of pathogens on produce. If not removed, these pathogens can reduce shelf life as well as create food safety concerns, particularly with crops that are field-packed and not subject to a postharvest wash.

Michael Larose, agriculture market segment manager at BioSafe, said that the company's Organic Materials Review Institute (OMRI)-listed crop protectant and food safety products have allowed small direct-market growers "to confidently champion their produce as naturally grown, naturally fresh, from field to fork."

Beginning with preharvest safety, BioSafe products have an emphasis on sustainability. For example, OxiDate 2.0 foliar bactericide/fungicide is safe for use right up until the day of harvest, and it reduces general bacterial coliforms and fungal/mold pathogens, Larose said. This foliar application spray is one of the first lines of defense in a food safety program.

Also important in the field is the safety of the water supply. Treating irrigation water to reduce any pathogen load to acceptable water quality standards can typically be done using chlorine or other oxidizing agents. Ultraviolet, copper or sand filtration methods can also eliminate water pathogens in susceptible systems. Protecting water sources from runoff and fecal contamination, delivering water to the root zone and not the edible portion of produce when practical, and not irrigating sensitive plants just prior to harvest are some routes growers may take to reduce the risk of water contamination.

BioSafe's SaniDate 12.0 MicroBiocide can be used for irrigation water treatments with no runoff restrictions. It is not pH-dependent, and it is also labeled for postharvest wash water use, as well as for treating effluent wastewater, Larose said.



Certain crops, such as potatoes, which are meant for long-term storage, can be effectively treated to prevent spoilage from common pathogens that occur during storage.
Photo by Scott Bauer, courtesy of USDA-ARS

Postharvest treatment

Postharvest washing of produce is another step in the prevention of foodborne illnesses.

"Prevention of contamination is preferred over corrective actions once contamination has occurred. However, antimicrobial chemicals in processing water are useful in reducing microbial buildup in water and may reduce microbial load on the surface of produce," according to a Food and Drug Administration (FDA) guide on food safety (http://www.fda.gov/Food/GuidanceRegulation/GuidanceDocumentsRegulatoryInformation/ProducePlantProducts/ucm064574.htm). "The effectiveness of an antimicrobial agent depends on its chemical and physical state, treatment conditions (such as water temperature, acidity [pH], and contact time), resistance of pathogens, and the nature of the fruit and vegetable surface."

While many advocate the use of chlorine as a disinfectant for produce, as well as for packing equipment and environmental surfaces, and it is approved for use under the National Organic Standards, many organic or natural growers are concerned about potential harmful disinfectant byproducts that can occur following the use of chlorinated compounds.

One chlorine alternative wash water additive that can be used to wash harvested produce is BioSafe's SaniDate 5.0, a liquid sanitizer that is "labeled to control human health pathogens, as well as spoilage organisms that impact product quality and shelf life," according to Larose. This product, he said, "offers versatility to the user, allowing them to apply in field-pack wash tanks [and] packing line spray bars, and allows for use as a hard surface sanitizer."

BioSafe's products use activated peroxygen chemistry (APC), which "provides the highest level of sanitation and water treatment power, as well as being easier to use, handle [and] monitor, and most importantly is safer than chlorine components," Larose stated. "In 1998, BioSafe Systems became the first company to register and introduce the use of activated peroxygen chemistry for use in crop protection. In today's volatile chemical market, it's important that the chemistries that are put on our food have been validated and proven to be effective, but more importantly, that they are safe for our consumers and our environment."

Peroxygens do not produce harmful byproducts and are effective against a wide range of microorganisms. They do have corrosive properties and can cause harm if improperly used, ingested or inhaled, as can chlorine derivatives. They may offer a more environmentally friendly alternative to growers concerned about chlorine, as they are fully biodegradable.

Other nonchlorinated alternatives are available for growers as well. Decco US Post-Harvest, Inc. has a full line of organic postharvest produce products, including its natural salt-based, organic alkaline cleaner, DECCONatur Kleen. This is used as a produce wash or dip to remove pathogens postharvest.

Green Valley Natural Plant Wash, manufactured by Western Nutrients, is a natural soap, salt-based produce wash for use before and after harvest. The product is available in several strengths, is OMRI-listed, and "is an excellent new-generation product for washing any type of agricultural commodity pre- or postharvest," according to product literature.



Treating irrigation water to reduce any pathogen load to acceptable water quality standards can typically be done using chlorine or other oxidizing agents.
Photo by Jack Dykinga, courtesy of USDA-ARS.

Packinghouse and equipment cleaning

Products that sanitize packing equipment, field equipment, tables and floors in the packinghouse and other food contact surfaces are an important part of on-farm safety routines. Pre- and post-use treatments for all equipment and food areas should be standard in any on-farm food safety plan. And don't forget bins, crates, floors, walls and even the delivery truck. Any potential contact surface should be routinely cleaned to prevent contamination.

Decco offers a peroxygen-based surface sanitizer, Peraclean, for environmental use, as well as OMRI-listed equipment cleaners. BioSafe's product line also encompasses equipment sanitation.

"Packers should implement an equipment sanitation step under the guidelines of their current food safety plans," Larose said. "BioSafe Systems works with our customers to implement our APC into their food safety program, providing them with consultation and support, as well as the necessary equipment to accurately dose and monitor their sanitation and water treatment applications."

Storage, processing and beyond

When produce is stored, spoilage will ultimately occur. Certain crops, such as potatoes, which are meant for long-term storage, can be effectively treated to prevent spoilage from common pathogens that occur during storage, including pink rot, late blight tuber rot and pythium leak. Applying a postharvest, prestorage protectant can prevent these pathogens from spoiling a crop.

Another Decco product, Bio-Save 10 LP, is a naturally occurring biological control agent for postharvest use that protects against mold and rot in many produce items. It is labeled for use on citrus, cherries, apples, pears and potatoes. The company also offers a line of natural, organic-approved coatings to assist in maintaining freshness. These include beeswax/plant oil, carnauba wax-based, or a combination of beeswax and carnauba-based coatings.



After harvest, washing produce is a necessary step in the prevention of foodborne illnesses.
Photo by Alex Proimos (CC-BY -2.0), via Wikimedia Commons.

Processed foods may require extra precautions to prevent microbial damage on cut surfaces, as well as to reduce browning and surface decay. BioSafe offers products specifically for storage and processing needs, Larose said.

The company also offers consumer products for produce washing at home, including the recently introduced SaniDate Fruit & Vegetable Wash.

"Establishing a field-to-fork consumer strategy, BioSafe Systems' products encompass all facets of the production process, including crop protection, water treatment, food safety in packing and processing plants, all the way to retail food safety solutions," Larose said. "Field-to-fork is a unique concept for an agrichemical manufacturer and has provided BioSafe Systems unique opportunities and relationships in all facets of the food production channel."



Michael Larose, agriculture market segment manager at BioSafe, said that the company's OMRI-listed crop protectant and food safety products have allowed small direct-market growers "to confidently champion their produce as naturally grown, naturally fresh, from field to fork."
Photo courtesy of BioSafe Systems.

Taking precautions

Taking extra steps to ensure food safety isn't just for the big operations with many stops before their produce lands on someone's plate; small growers with direct-to-consumer sales also need to pay attention. Simple steps and rules can prevent some food safety issues from ever occurring. The hygiene of workers who come in contact with food or food contact surfaces is critical. Not only is proper hand washing paramount, but infectious diseases can also be spread via cuts and wounds or through the air. Workers who have symptoms of infectious diseases should not be working unless medically cleared.

Keeping packing, processing and storage facilities free from field dirt can go a long way in preventing pathogen buildup. Keep shoes and clothes used in the field outside of packing and storage facilities as much as possible. Keep bins or containers stored outside covered, and wash them before use. Prevent pests from accessing food packing and storage areas. Be mindful of airborne contaminants from dust and pollutants that may enter facilities.

While care and common sense go a long way, products designed to reduce the risk of contamination in the field or postharvest in packinghouses, storage sheds or processing lines provide a second line of defense. Natural products, which can enhance food safety from preharvest to storage and even beyond the farm, can make adhering to food safety practices just a bit easier, particularly for growers trying to grow as naturally as possible.

The author is a freelance contributor based in New Jersey. Comment or question? Visit http://www.farmingforumsite.com and join in the discussions.