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Research improves fresh fruit, produce
By Rebekah Ray and Charmain Tan Courcelle
MISSISSIPPI STATE -- Mississippi Agricultural and Forestry Experiment Station food researcher Juan Silva is making it safer to eat the five to seven servings of fruits and vegetables the U.S. Department of Agriculture recommends for daily consumption.
"As attractive as it is at a roadside fruit stand or in the produce section of a grocery store, fresh produce may be contaminated with pathogenic microorganisms like Clostridium botulinum, Escherichia coli, Salmonella, Shigella and others," Silva said. "In the past, washing fruits and vegetables with running water, or even soap and water, had been the primary line of defense to remove these pathogens and any chemical residues present."
Now, better prevention mechanisms against contamination are needed. Silva said these mechanisms are divided into Good Agricultural Practices for on-farm application and Good Manufacturing Practices for packing houses and distributors.
Silva is actively involved in a project that trains and educates Extension agents and other personnel who provide information to producers about safe fresh food production.
"Previously, farmers were not aware of how their farming practices would affect consumer health. There was more concern with quality and yield," Silva said.
However, ensuring that fresh fruits and vegetables are safe for consumption is difficult. There are no additional control and safety measures, such as salting and cooking to high temperatures, to eliminate food-borne pathogens from fresh produce. According to the Food and Drug Administration's Guide to Minimize Microbial Food Safety Hazards for Fresh Fruits and Vegetables, preventing microorganism contamination is greatly favored over cleanup of tainted produce.
"Good Agricultural Practices were developed by the FDA and other participants to minimize the presence of pathogenic microorganisms in fruits and vegetables," Silva said. "They are on-farm source controls that prevent food-borne disease as much as possible."
Fruit and vegetable processors already follow Good Manufacturing Practices, including proper building sanitation and good employee hygiene. Now, produce growers and packers are encouraged to follow both sets of guidelines in all aspects of fresh fruit and vegetable production and distribution.
These practices include testing and maintaining the quality of water used for irrigation and washing, wastewater management and treatment, proper field hygiene and sanitation, and composting, which actively decreases the presence of microorganisms in untreated manure.
Potential sources of microbial contamination are agricultural water and soil, as well as the farm workers themselves, but any step in the process of moving produce from farm-to-table can introduce harmful microbes.
The FDA's Hazard Analysis Critical Control Point system includes fresh fruit and vegetable processing or canning under a program that identifies and monitors specific biological, chemical or physical food-borne hazards that can adversely affect the safety of food.
Previous safety guidelines for the seafood, meat and poultry industries have led to significant reductions in the incidence of food-borne pathogens. New Hazard Analysis Critical Control Point-like guidelines controlling the safety of fruits and vegetables may also help reduce the possibility of any food-borne disease stemming from consumption of raw fruits and vegetables.
Silva is also investigating the safety of organic fertilizer use. With Kent Cushman, a MAFES researcher at the Northeast Mississippi Branch Experiment Station, Silva is conducting research on the safety issues surrounding the application of swine waste as a fertilizer for different crops. In another project, conducted in collaboration with Alcorn State University, Silva is studying the safety of organic fertilizer use on muscadines.
Direct contact between the edible portions of produce and contaminated soils, including those fertilized with raw or improperly treated manure, greatly increases the risk of produce contamination. An understanding of this relationship and its effects is required to promote safe use of animal waste products in fruit and vegetable production.