USDA-ARS Investigate Use of Peanut Skins in Poultry Feed
No traces of peanut allergens were detected in the eggs or meat
Ondulla Toomer, a research chemist with the Agricultural Research Service (ARS) in Raleigh, North Carolina, is investigating other uses for peanut skins that would typically be discarded as trash, the ARS said in a news release.
His studies at the agency’s Food Science and Market Quality and Handling Research Unit in Raleigh suggest a range of food and feed uses that could potentially open the door to new markets at added value for peanut skins.
Instead of landfill waste, Toomer sees untapped nutritional potential in paper-thin skins, which are packed with protein, carbohydrates, fats, fiber, minerals and vitamins. Peanut skins also contain bioactive compounds, including antioxidants that help neutralize molecules that are harmful to body cells called free radicals. Some, in fact, have levels of antioxidant activity equal to green tea, grape skins and other sources.
On the livestock feed front, Toomer and his collaborators are exploring the benefits of adding peanut skins to poultry feed. However, peanut skins contain tannins, which can reduce the digestion of protein from food. Researchers have begun to evaluate the low inclusion levels (4%) of peanut skins to determine the optimal amount that can be added.
Aware of peanut sensitivities in some consumers, the researchers also checked for the presence of allergenic peanut protein in egg and meat samples produced from birds fed diets containing peanuts. However, no traces of peanut allergens were detected. Another interest: to determine if the birds fed with peanut skins excrete less Salmonella bacteria, which can pose a problem of human food safety with the consumption of poultry meat or eggs.
On the functional food front, researchers are comparing the concentrations of bioactive compounds in different colored peanut skins, which range from red, tan and brown to white, black and variegated.
Toomer said profiling the nutritional chemistry and properties of peanut skins is a key step in determining the best way to use them, with potential benefits for producers and consumers. More generally, Toomer’s efforts are part of the overall mission of the ARS laboratory to improve the productivity, processing, end-user quality and nutritional value of not only peanuts, but also cucumbers, sweet potatoes , peppers and cabbage.