Orange peels are mostly treated as waste, but since the Food and Drug Administration considers natural orange peel extracts safe for human consumption, researchers want to put the peels to better use. Yu Wang, an assistant professor of food science and human nutrition at the UF Institute of Food and Agricultural Sciences, plans to lead a research team to ensure extracts from orange peels improve the gut’s ability to stave off fatty linings in your arteries. Recent research has shown that gut bacteria help develop cardiovascular disease. When they feed on certain nutrients during digestion, gut bacteria produce trimethylamine N-oxide (TMAO) as a byproduct. TMAO levels are powerful predictors of future cardiovascular disease, according to researchers at the Cleveland Clinic.
Wang and her colleagues will study how orange peels promote gut health and overall human health. Americans generate about five million tons of orange peels a year. “This research could be critical to enhancing the cardiovascular health of millions of people worldwide,” said Wang says. “In addition to improving consumers’ health, our research results could provide additional economic returns, benefiting U.S. agriculture and food systems.”
For the new UF/IFAS-led project, researchers hypothesize that orange peels will modify gut microbiota and help prevent atherosclerosis, a disease characterized by fatty deposits on the inner walls of arteries. When gut microbiota break down chemicals called choline and carnitine, the process eventually produces trimethylamine (TMA). Enzymes can then convert TMA into TMAO. But orange peels contain components that interfere with TMA enzymes. Researchers believe that action will help prevent atherosclerosis. To test these hypotheses, the researchers will combine animal studies with enzyme tests to assess how orange peel extract consumption can prevent cardiovascular diseases.
In her own preliminary work, Wang experimented with three groups of mice to see if she was going in the right direction with her research proposal. One group was fed a regular diet, the second was fed a regular diet plus carnitine, which induced TMAO. The third group was fed a regular diet, carnitine and orange peels. They found orange peels altered the composition of bacteria in colons in the mice fed with a regular diet, carnitine and orange peels. "Within three years, we expect to understand more about the mechanisms associated with orange peel consumptions, TMAO formation and the prevention of atherosclerosis," Wang added. "We hope this project cannot only positively impact human cardiovascular health via the promotion of gut health, but will also provide a simple and an efficient usage of orange peels."
The Economic And Environmental Advantages Of Repurposing Grape Waste
The wine industry goes through a lot of grapes to produce the over 31 billion bottles that are purchased the world over each year. However, you don’t have to be a vintner to know that not all of the grape goes into the wine. About one-quarter of the fruit including the skins, seeds, and stalks, are considered waste and end up in landfills. What’s more, even though it’s organic, large volumes of grape waste can be harmful to the environment.
The good news is that researchers have discovered a way to use the typically discarded grape remains in commercial applications and even to extend the shelf life of some foods. These research findings, presented by Changmou Xu, Ph.D., and his team, feature over 13,000 exhibitions and demonstrations covering an extensive variety of scientific topics.
One problem with grape waste - also called pomace - is that it carries the residue of fertilizers and pesticides. These toxic substances can seep into the environment, causing pollution in ground and surface water supplies. Plus, pomace has low pH, which can increase the acidity of soil. Dr. Xu points out that grape pomace in landfills attracts flies and other pests and can increase the spread of disease.
The Image Of Pomace
The Food and Agriculture Organization of the United Nations reports that the wine industry worldwide generates around 14 million tons of grape waste per year. While winemakers grapple with how to handle the waste, the researchers at the University of Nebraska-Lincoln, headed up by Xu, want to change pomace’s image. Rather than a waste problem, the group views it as a renewable resource, one that can supply grape oils and ingredients for health products such as antioxidants and dietary fibers. Putting pomace to work for commercial use is a two-for-one solution. On top of reducing environmental pollution, it’s also capable of increasing grapes’ economic value, making the wine industry more profitable.
Xu’s team uses holistic methods to find the best ways to remove nutrients from grape waste and to identify and separate them for use in commercial products. The techniques also remove pesticides that may be present. Xu explains that pomace has a wide range of uses including providing antioxidants and grape seed oil for pharmaceuticals, dietary supplements, and cosmetics. Winemakers and others in agricultural industries can also use pomace for fertilizer or compost.
Additionally, the team is researching ways to use pomace in food, including combating food-borne pathogens and extending the shelf life of high-fat foods. They found that adding some components derived from grape waste to popular items such as potato chips and mayonnaise inhibited oxidation of lipids, which helped those products last longer, even in warm temperatures. Dr. Xu hopes that his team can optimize their process so pomace-derived compounds can be more widely used, fulfilling the growing consumer demand for food labels that list natural ingredients.