Effect of incorporation of peanut skin powder on some quality characteristics of peanut (Arachis hypogaea) butter

Abstract

Peanut skin is a food waste with great potentials as a source of natural antioxidants in food systems. The study examined the effect of adding peanut skin (PS) powder on selected quality characteristics of produced peanut butter. The PS powder at varying levels (1%, 2%, and 3%) was incorporated and into processed peanut butter samples. Peanut butter with no PS and commercial peanut butter served as controls. Nutrient composition, antioxidant and sensory properties of the peanut butter samples were determined. There were differences (p < 0.05) in all proximate composition parameters. While protein and fat content decreased, content increased with PS powder level. The protein and fat contents ranged from 24.31% to 26.28% and from 58.58% to 52.85%, respectively. The fibre content varied from 0.82 for the control sample to 1.78% for peanut butter with 3% PS. The zinc, Vitamins E and B3 levels increased with levels of PS powder. The total phenolic content ranged from 64.2 to 86.79 mg garlic acid extract (GAE) 100-g ^–1 and increased with PS powder levels. The DPPH activity (1,1-Dihenyl-2-picrylhydrazyl radical scavenging activity) increased significantly with PS powder content. The sample with 3% PS had the highest overall acceptability score. It is concluded that acceptable peanut butter with enhanced antioxidant activity could be produced by incorporating PS at up to 3% level.