A portion of oranges previously though to be useless may actually provide some health benefits. A new study from the University of Florida found an extract in orange peels could be used to improve cardiovascular health.
Heart disease is the leading cause of death for just about every adult demographic according to the Centers for Disease Control and Prevention. And new research attributes cardiovascular disease to some types of gut bacteria and the compounds they produce.
According to the Cleveland Clinic, there is a type of gut bacteria that during digestion produces trimethylamine N-oxide (TMAO), which at certain levels is a predictor of cardiovascular disease.
UF researcher Yu Wang and her team were interested to know if orange peel extracts, which are rich in phytochemicals, could reduce TMAO and trimethylamine (TMA) production. In order to conduct their research the scientists tested two types of extracts. Both polar fraction and non-polar fraction were taken from orange peels through the use of solvents.
"If you imagine your salad dressing, anything in the water or vinegar part are the polar fraction; anything in the oil away from water is the non-polar fraction," Wang said. "The solvents we used were not exactly like water and oil, but they possess similar polarity."
The study showed the non-polar fraction extract from the orange peels was able to inhibit the production of harmful chemicals and the polar fraction extract produced a compound called feruloylputrescine, which significantly inhibits the enzyme responsible for TMA production.
"This is a novel finding that highlights the previously unrecognized health potential of feruloylputrescine in reducing the risk of cardiovascular disease," Wang said.
Approximately five million tons of orange peels are left over as part of the production of orange juice in America each year. And much of that is in Florida. Nearly 95 percent of the state's oranges are used for juice. About half of the peels are used to feed cattle. Some are used to produce various solvents and household cleaning products, but much of the rest is just discarded.
The U.S. Food and Drug Administration says natural orange peel extracts are safe for human consumption so Wang wanted to look at potential uses. "These findings suggest that orange peels, often discarded as waste in the citrus industry, can be repurposed into valuable health-promoting ingredients, such as diet supplements or food ingredients," she said.
Click here to read more in the Journal of Agricultural and Food Chemistry.