Fruit and vegetable consumption has grown significantly in the past two decades as the health benefits of these crops have been emphasized. Unfortunately, the incidence of food borne illnesses has also increased. In some cases, the financial impact on the growers of the crops associated with these incidents has been devastating. This means that it is important for all growers to be aware of food safety practices that minimize contamination of their crops with human pathogens. The most important disease organisms are Salmonella, E. coli O157:H7, Listeria, Shigella and Bacillus cereus. The primary path- ways for these pathogens to enter the field or packing shed are: contaminated irrigation or processing water, poor field/packing shed worker hygiene, improperly aged or treated organic soil amendments (manure, etc.), domestic or wild animals entering the field, contaminated harvest equipment, inadequate or unsanitary processing and storage conditions and improper transportation.
The following checklist of recommendations should be considered during crop production, harvest, processing and transport.
This is very important in documenting the steps you take to ensure that you have complied with food safety recommendations. Some of the important things that need to be recorded are:
• Planting date(s) – varieties, suppliers, etc.
• Applications of fertilizer, pesticides or any other inputs.
• Water testing dates and results.
• Employee training – type of training (general safety, food safety etc.), dates, who was trained, follow-up training.
• Animal entry – dates when checked or observed, type(s) of animal signs, what action(s) you took to try to solve or mitigate the problem.
• Equipment maintenance – dates, type of maintenance, which piece of equipment, cleaning.
• Harvest date(s) – sanitation of harvest implements and harvest containers.
• Cleaning schedule for processing and storage facilities.
• Pest control program in processing and storage facilities – who does the program, treatment or trapping dates.
• Maintenance of refrigeration equipment and temperature of storage rooms.
• Dates of farmers’ markets or other marketing options.
• Package identification.
To prevent field and packing shed workers from contaminating crops:
• They should be trained in hand washing - use plenty of soap and water, wash for at least 20 seconds, clean under fingernails and between fingers, rinse under clean water and dry hands with a single-use towel. Wash hands before they start work, after each break, after handling unsanitary
items such as animals, manure, etc. and after using the toilet.
• They should not eat, chew gum, use tobacco, spit, urinate or defecate while in growing/processing areas.
• They should use the toilet/hand washing facilities and use them properly.
• Workers who show signs of diarrhea, vomiting, fever, jaundice or infected wounds should not handle fresh produce.
• They should use single-use cups or fountains for drinking water.
• The grower, packer or labor contractor should also provide signs that reinforce good hygiene, both in the field and in the packing shed.
Water needs to be tested to know whether it is contaminated with unacceptable levels of bacteria. While there is no standard for food safety testing levels, a number of commodity groups have used the recreational water standard as a safe level. Water should be tested as near to the point-of-use as possible. All of the water used to produce and process crops should be tested (pesticide spray water, water used in processing, etc.).
Unprocessed manure is a perfect medium to support bacterial growth. Many food safety programs do not allow the use of unprocessed manure. Only properly composted or aged manure can be used. They also require that root crops not be grown for one year after manure application. If untreated manure must be applied shortly before planting, apply and incorporate at least two weeks before planting and don’t harvest the crop for 120 days after application. If the 120 day waiting period is not feasible, apply only properly composted or aged (at least one year) manure. Composted manure use as a side dressing is very difficult. If you must use it this way, do all you can to reduce manure-crop contact and, if possible, incorporate it as soon as you can.
The following web sites have additional information on food safety:
U.S. Food & Drug Administration Guidance for Industry: Guide to Minimize Microbial Food Safety
Hazards of Tomatoes: Draft Guidance. July, 2009
Commodity Specific Food Safety Guidelines for the Production and Harvest of Lettuce and Leafy Greens. California Leafy Green Handler Marketing Board. January, 2012
Food Safety Begins on the Farm: A Growers Guide. Cornell University. 2000