Citrus to Reduce Foodborne Illnesses

By Sandy Almendarez, Natural Products Insider, November 22, 2010

CHICAGO—Dried orange peel/pulp may be a waste product to many orange juice manufacturers, but this precious material can help save billions each year by reducing foodborne illnesses, according to Todd R. Callaway, Agricultural Research Service/USDA Food and Feed Safety Research Unit, at the Natural Health Research Institute’s (NHRI) symposium on the cost- effectiveness and safety of dietary supplements on Nov. 18, 2010.

The general population has a negative perception of the food industry, and most of that is based on the foodborne illness linked to meat, Callaway noted. With 27 percent of the population suffering from foodborne illnesses each year costing the United States more than $150 billion per year, dried orange peel/pulp can help improve the costs by eliminating the transfer of disease from cattle to human.

He highlighted a previous study that showed orange oils (e.g., limonene) improve animal health and productivity (especially in swine). He added orange peel/pulp is a good source of pectin and fermentable fiber to ruminal microbial population, which can help reduce harmful bacteria.

He presented research conducted by USDA that found dried orange pulp reduced pathogen populations in ruminal fluid in vitro fermentations. Further, he noted three in vivo studies with cattle found orange to be effective in reducing harmful bacteria.

The first study involved sheep (n = 24) that were fed feedlot rations with 0-percent, 10-percent or 20-percent dried orange pellets for 14 days. Then, the sheep were orally inoculated with 109 CFU Salmonella Typhimurium. While he said sheep who were offered a the 20-percent diet refused to eat all of the orange pellets, the 10-percent orange pellet diet reduced Salmonella populations in rumen, cecum and rectum.

A second sheep study was designed in much the same way as the first, except the 24 sheep were fed either feedlot rations with 0-percent, 5-percent or 10-percent dried orange pellets for 14 days instead of the higher proportions of the previous study. The 5-percent and 10-percent diets both reduced E. coli O157:H7 populations in rumen, cecum and rectum.

The orange pellets also worked to reduce E. coli in pigs. In another study, pigs (n = 36) were fed finishing rations with 0-percent or 10-percent dried orange pellets for 28 days and were then orally inoculated with 107 CFU E. coli K88 (diarrheagenic) PWECD . The pigs were sacrificed daily beginning one day after inoculation for four days. Again, the pellets reduced the E. coli in the cecum, colon and rectum.

Callaway concluded by saying these results have the potential to translate to humans, and he encouraged the dietary supplement industry to look to orange peel as an antibacterial ingredient.