Acceptability of peanut skins as a natural antioxidant in flavor coated peanuts

Authors: Christman, Lindsey; Dean, Lisa; BUENO-ALMEIDA, CAMILLA - North Carolina State University; Weissburg, Jacy

Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/10/2018
Publication Date: 9/5/2018
Citation: Christman, L.M., Dean, L.L., Bueno-Almeida, C., Weissburg, J.R. 2018. Acceptability of peanut skins as a natural antioxidant in flavor coated peanuts. Journal of Food Science. 83(10):2571-2577. https://doi.org/10.1111/1750-3841.14323.
DOI: https://doi.org/10.1111/1750-3841.14323

Interpretive Summary: Peanut skins are a waste product from producing peanut butter and other peanut products. They contain high levels of compounds with antioxidant properties but also have bitter flavors. The antioxidant compounds can be extracted and dried to powders that can be added to foods to increase their antioxidant strength. This study added the powder to seasoned coating mixtures for peanuts. When tested by consumers, the flavored peanuts were acceptable at levels that increased the antioxidant power of the peanuts to that of berries such as blueberries and strawberries. This work showed that a waste product from the peanut industry can be used to add value to peanuts.

Technical Abstract: Peanut skins are a low-value byproduct of the peanut processing industry. Following their removal during the preparation of common peanut products, they 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 as a functional food ingredient. The aim of this study was to evaluate a new product that included encapsulated phenolic extract from peanut skins in a flavored coating for peanuts. The phenolic compounds were extracted from peanut skins and then encapsulated in 10.5 % (w/w) maltodextrin in order to reduce the bitterness. The encapsulated phenolic extract was added at varying concentrations to both a honey roasted and chili lime coating that was then applied to roasted peanut. The resulting total phenolic content and antioxidant potential of the coated peanuts was evaluated by the Folin- Ciocalteu, DPPH, and ß-carotene bleaching assays. A best estimate sensory threshold for the peanut skin extract in the honey roasted and chili lime coating was found to be 12.8% (w/w) and 16.6% (w/w) respectively. The total phenolic content and antioxidant capacity for both the honey roasted and chili lime coated peanuts at their threshold was found to be significantly higher than control peanuts that did not contain any peanut skins in the coating. The increased antioxidant activity and unaltered flavor profile at the sensory threshold levels of peanut skins demonstrated their potential as a functional food ingredient.