Issue link: http://read.dmtmag.com/i/590163
www.goodfruit.com GOOD FRUIT GROWER NOVEMBER 2015 23 a possibility these existing treatments are not enough to ensure the safety of the product all the time," Sablani said. "We've been thinking UV-C light could be another intervention." The researchers believe that a UV-C treatment could be used to satisfy the Food and Drug Administration's requirements under the Food Safety Modernization Act. It could also be used by organic fruit packers who can't use chemical sanitizers. Interest in the technology is high, Sablani said, because it's simple to implement and inexpensive. Inoculated For the WSU study, researchers used fresh organic Fuji apples, d'Anjou pears, cantaloupes, and raspberries. Small slices from the fruit were inoculated with E. coli and L. monocytogenes and then treated inside a table-top UV-C light emitter. Sablani and his colleagues found that the light treat- ment could reduce pathogens by up to 99.9 percent on apples and pears. L. monocytogenes was more resistant to the UV-C treatment than E. coli. Fruit were inoculated with high levels of the pathogens in order to put the treat- ment to the test. In a real-life setting where good agricul- tural practices are used, pathogen populations on fruit would be significantly lower and the treatment would likely be more effective on both pathogens, he said. The treatment was more effective on smooth-skinned fruit than those with rougher surfaces, dimples, seeds, or druplets and was more effective on apples than on pears. "If you have smoother-skinned fruit, then this tech- nology is really great," Sablani said. "If the fruit are rough but the contamination level is low, it also works quite well." Tunnel UV-C is harmful to the naked eye, but UV-C lamps could be enclosed behind protective barriers inside a tunnel on a packing line, with fruit exposed to the light as it passes on a conveyor belt. In the experiments, most, but not all, of the microbes were killed in the first minute of treatment. Sablani said the dose could be increased by using more lamps to ensure that the treatment would be effective at the speed at which fruit typically move along the packing line. There would be no need to slow down the line or make major modifications. UV-C treatment has no or minimal effect on the sensory quality of fruit, Sablani reports. After the exper- iments, sensory panels consisting of 30 to 40 people were unable to detect a difference between treated and untreated pears. However, after the pears had been held for four weeks they could perceive differences in sensory parameters. But after fruit had been stored for an addi- tional four weeks, fewer panelists could perceive differ- ences in overall quality between treated and untreated fruit. Sablani said green is affected more by UV-C light than orange or red. The treatment does not affect shelf life, as it affects only the surface of the fruit. Also taking part in the experiment were: biosystems engineer Dr. Roopesh Syamaladevi, Extension food safety specialist Dr. Karen Killinger, and food safety spe- cialist Dr. Achyut Adhikari, who is now at Louisiana State University. The study was partially funded by a grant from the Biological and Organic Agriculture program of WSU's Center for Sustaining Agriculture and Natural Resources. • COURTESY ROOPESH SYAMALADEVI, WSU Pathogens on the surface of organic pears were significantly reduced after exposure to UV-C light. Milton Knouse was looking for research-proven, innovative ways to increase quality, effi ciency and productivity on their 600-acre fruit farm when he began using AgroLiquid products. He was initially impressed with height growth in his young trees, but then, "I noticed the lateral limb development in the trees, which means more fruit bearing surfaces for increased production… you can actually measure the difference." Milton has also realized an increased fruit size using AgroLiquid products, "The bigger the fruit, the more bushels you produce. We were quite pleased with that." When selecting your fertilizer products, remember that for more than 30 years, AgroLiquid has provided the research-proven performance growers trust. To learn more visit agroliquid.com QUALITYProducers Trust Agro-Culture Liquid Fertilizers "...more fruit bearing surfaces for increased production…" Milton Knouse Knouse Fruitlands Inc. Good Fruit Grower_Milton_2/3.indd 1 9/10/15 7:22 AM