A study published in the Journal of Food Science shows that adding peanut skins to peanut butter may improve the nutrition while maintaining the flavor. Peanut skins are a low-value residue material from peanut processing that contains naturally-occurring phenolic compounds. 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.
The researchers added peanut skins to peanut paste and peanut butter in concentrations of 0.0%, 0.5%, 1.0%, 5.0%, 10.0%, 15.0%, and 20.0% (w/w). The peanut skins, peanut paste, and peanut butter used in the study had initial total phenolic contents of 158, 12.9, and 14.1 mg GAE/g, respectively. Descriptive sensory analysis indicated that the addition of 1% peanut skins did not change intensity of descriptors in the sensory profile of either peanut paste or peanut butter. Adding 5% of peanut skins resulted in significant differences in woody, hulls, skins; bitter; and astringent descriptors, while a 10% peanut skins addition resulted in significant differences in most attributes toward more negative flavor.
The researchers concluded that the improved nutritional qualities and unchanged flavor profile occurring with low levels of peanuts skins in peanut paste and peanut butter suggest potential application of this technology in various food industries.