(April 16) LOS ANGELES — Post-harvest handling and food safety were the topics of the day at the Science Symposium at the International Fresh-cut Produce Association’s annual conference April 13.

Moderators Jim Gorny, technical director for the association, and Gerald Sapers, a researcher with the U.S. Department of Agriculture’s Eastern Regional Research Center in Wyndmoor, Pa., introduced a group of speakers who covered topics ranging from fresh-cut quality to wash water disinfectants.

Sapers said processors need to be careful when choosing what treatments they use, because the wrong choice could lead to problems. He cited treatments used on apples as an example.

“Some treatments tend to induce darkening in apples,” he said.

Larry Beuchat, a professor at the University of Georgia’s Center for Food Safety, Griffin, Ga., said that in addition to changing appearance, treating produce to eliminate pathogens also can change the shelf life of the product, depending on what treatment is used.

Lettuce treated with organic acids can suffer a loss of texture, for example. In one study, however, apples treated with lactic acid and hydrogen peroxide for e.coli, listeria and salmonella showed no difference from apples that were untreated.

Bassam Annous, also of the Eastern Regional Research Center, said current research into the area of wash water disinfectants is aiming to identify sources of microbial contamination and develop effective new treatments as well as new decontamination equipment.

He said chlorine is one of the few chemicals used to manage both post-harvest diseases and water-born diseases. He noted that some problems experienced when using chlorine may be due to the erratic quality of the water supply used when mixing the wash.

Annous said he recommended using hydrochloric acid as a buffering agent and continuous monitoring of residual chlorine and pH levels in any washing process.

Lloyd Simmons, food microbiologist for Food Science Australia, Werribee, Victoria, said it is important for companies to establish food safety objectives. He likened these objectives to barricades that keep foodborne illnesses away from consumers.

He said that establishing a set of food safety objectives is imperative to maintaining a safe and clean supply chain.