Applications of peanut skins as a functional food ingredient

Authors: CHRISTMAN, LINDSEY - North Carolina State University; Dean, Lisa

Submitted to: American Peanut Research and Education Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 3/31/2017
Publication Date: 7/12/2017
Citation: Christman, L., Dean, L.L. 2017. Applications of peanut skins as a functional food ingredient. American Peanut Research and Education Society Abstracts. Vol. 49.

Interpretive Summary: One of the biggest waste streams from peanut processing plants is peanut skins. They have no value and are either dumped into landfills or given away to be used as a filler ingredient in animal feed. Like many plant materials such as fruit peels, they contain high levels of phenolic compounds that have been associated with human health benefits. This work showed that the important compounds can be extracted from the waste peanut skins and used as an ingredient in flavor coatings for peanuts. The end result is a peanut snack product with appealing flavors that are not affected by the addition of the peanut skin extract, but has higher levels of bioactive compounds than a peanut with the skin intact.

Technical Abstract: Peanut skins are a low-value byproduct of the peanut industry, with hundreds of thousands of tons being produced annually. Following their removal during the preparation of common peanut products, peanut skins are either discarded or used as a minor component of animal feed. Recent studies have found peanuts skins to be rich in health promoting phenolic compounds and thus have potential to create a market for this material. This study evaluated the use of extracts from peanut skins as a nutraceutical food ingredient by incorporating it into a coating for peanuts. In order to reduce the bitterness associated with the high concentration of polyphenols in the extracts, maltodextrin was used as an encapsulation agent. The encapsulated extract was added at varying concentrations to both a honey roasted and chili lime coating that was then applied to roasted peanut through a panning process. The resulting antioxidant potential of the coated peanuts was investigated. A best estimate threshold for 10.5% maltodextrin-encapsulated peanut skin extract in both the honey roasted and chili lime coating was found to be 12.8% (w/w) and 16.6% (w/w) respectively, based on the standard method (American Society of Testing Material; ASTM E-679).