Utilization of Peanut Skin Extracts as Functional Food Ingredients

Authors: Dean, Lisa; White, Brittany; Sanders, Timothy

Submitted to: US-Japan Coop Pgm on Dev and Util of Natural Products Abstracts Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 11/1/2015
Publication Date: 11/1/2015
Citation: Dean, L.L., White, B.L., Sanders, T.H. 2015. Utilization of Peanut Skin Extracts as Functional Food Ingredients. US-Japan Coop Pgm on Dev and Util of Natural Products Abstracts Proceedings. vol 15.

Interpretive Summary: The redskins of peanuts are usually discarded by peanut product manufacturers. They have been found to have high levels of health promoting compounds that are the same or very similar to those found in foods such as tea, dark chocolate and dark colored berries. These foods have been well advertised for their healthy properties. This work reports on ways to remove these bioactive compounds from waste peanut skins and transform them into a powder that can be mixed into other foods to increase their health promoting properties, especially their antioxidant levels. With these processes, foods such as peanut butter and milk chocolate will have antioxidant as high as dark chocolate or dark berries without changes in flavors.

Technical Abstract: Peanut skins are a by-product of the blanching industry that have not been utilized to their full potential. They have been found to contain significant quantities of compounds containing phenolic moieties such as catechins, procyanidins, and other polyphenols that have positive associations with human health. Peanut skins are an ideal candidate to be a low cost starting material to produce functional food ingredients. These compounds can be captured and isolated which overcomes issues of using intact peanut skins directly to food products. Extraction with food grade solvents and subsequent spray drying to produce free flowing powders has proven effective. These powders have antioxidant activity as measured by chemical assays such as ORAC and DPPH. They have also demonstrated anti-inflammatory effects on living cells. Undesirable components such as metal ions are concentrated in the extracts and can be removed by treatment with pulverized peanut hull material. Modulation of the bitter and astringent properties with the addition of maltodextrin during the production of the peanut skin extract powders has allowed for the successful incorporation of the extracts from peanut skins into food products such as peanut butter and milk chocolate to produce products with added health properties and little negative flavor impacts that are acceptable to consumers. Bitter and astringency descriptors were not increased more than 0.5 intensity units above the products without added peanut skin extracts while the antioxidant levels measured in Trolox units by the DPPH assay were increased to levels equal to high antioxidant foods such as dark berries and cocoa.