The study – published in the Journal of Food Science – backs the use of ‘low-value’ peanut skin residues to improve the nutritional value and shelf life of the popular spread by increasing levels of phenolic compounds.
Led by Timothy Sanders from North Carolina State University, USA, the researchers evaluated the nutritional, antioxidant, and flavour properties of peanut paste and peanut butter enhanced with peanut skins, finding that inclusion of the processing by-product into peanut butter formulations can help to improve nutritional values and shelf life – adding that there may be potential to utilise peanut skins to improve nutritional quality in other products.
“The use of this material to improve antioxidant capacity and shelf-life of foods can add value to the material and improve the nutritional value of foods,” write the researchers. “The improved nutritional qualities and unchanged flavour profile occurring with low levels of peanuts skins in peanut paste and peanut butter suggest potential application of this technology in various food industries.”
Peanut skins are a low-value by-products from peanut processing. However they contain naturally high levels of antioxidant phenolic compounds. As a result Sanders and his team evaluated the effects of adding peanut skins to peanut pastes and peanut butter.
The team added peanut the skins in concentrations of 0.5 to 20.0%.
Sensory analysis with a panel of tasters indicated that the addition of 1% peanut skins did not change intensity of flavour or sensory profiles of either peanut paste or peanut butter, whilst adding 5% skins or above resulted in significant differences in sensory attributes.
Therefore, the team concluded that the improved nutritional qualities and unchanged flavour profiles occurring with low levels of around 1% peanuts skins could provide benefits in terms of nutritional value and shelf life extension in various food industry applications.
Source: Journal of Food Science
Published online ahead of print, doi: 10.1111/j.1750-3841.2012.02953.x
“Flavor and Antioxidant Capacity of Peanut Paste and Peanut Butter Supplemented with Peanut Skins”
Authors: Chellani S. Hathorn, Timothy H. Sanders