Feb 18, 2009

Tomatoes and Peppers Need Safe Handling

Tomatoes and peppers are under the food safety microscope, and growers need to do everything they can to keep the image clean.

Leslie Bourquin, an associate professor at Michigan State University’s Department of Food Science & Human Nutrition, discussed the safe handling of tomatoes and peppers last December, in a presentation held during the Great Lakes Fruit, Vegetable and Farm Market EXPO.

According to Bourquin, about a quarter of the U.S. population (76 million people) experience some sort of foodborne illness every year. Those cases result in 325,000 hospitalizations per year, more than 5,000 (preventable) deaths per year and economic losses ranging from $10 billion to $83 billion per year.

Vegetables, fruit and nuts combine to cause roughly 56 foodborne outbreaks per year, which sicken thousands of people. Some outbreaks gain more notoriety than others. The 2006 E. coli outbreak in spinach put more than 100 people in the hospital and killed three. Last year’s salmonella outbreak sickened more than 1,400 people across the country. Tomatoes were the initial culprit; then peppers, Bourquin said.

As a result of all the recent outbreaks and the attention they’ve brought, the federal government has been putting pressure on produce industries to clarify and enhance their food safety practices. Bourquin pointed out United Fresh’s “Commodity Specific Food Safety Guidelines for the Fresh Tomato Supply Chain” as an example of those efforts.

The guidelines, published last July, divide the tomato supply chain into eight parts: open-field production, harvest practices, field packing, greenhouse production, packinghouse, repacking and other distribution operations, fresh-cut processing, and foodservice and retail.

Bourquin’s presentation focused on the guidelines relating to manure and microbial contamination. In sum: “Do everything you can to keep manure off produce.”

All manure, whether animal or human, can carry pathogens that contaminate produce. Preventing such contamination should be the main goal of any producer, according to Bourquin.

Bourquin made other points about on-farm manure handling: Active composting is preferred. Compost piles should be managed for high temperatures, good moisture, proper aeration and uniform mixing. Animals should be excluded from the compost area to prevent any re-contamination.

If not composted, manure should be stored for several months prior to field application. If manure is applied in spring to fruit and vegetable fields, wait 120 days to harvest. Don’t assume manure is “clean.” Keep records of manure and compost use (and know the source). Apply the manure to ground where perennials are being planted, and avoid low-growing crops like lettuce and beets or crops with leaves that are eaten by humans.

Bourquin had other bits of advice:

Wells are the safest source of irrigation water; ponds the next best.

Use trellis/staking where appropriate, such as for tomatoes.

Use plastic mulch and drip irrigation to reduce leaf wetting. Use organic mulches to reduce splash.

Keep wildlife out of production areas as much as possible. No dogs or other pets in the field.