Total Antioxidant Capacity of Arachis hypogaea Seed Kernels and Coats: An Analytical and Sensory Investigation

Antioxidants are critical components of the body's defense system, providing protection against cell-damaging free radicals responsible for oxidative damage of biomolecules. Humans benefit from the consumption of plants with high antioxidant content, which have been shown to positively impact health. In plant physiology, antioxidants provide protection from biotic and abiotic stress, particularly during the development of seeds and germination. Peanut seeds and seed coats have been shown to contain several beneficial antioxidants and are a good source of phytonutrients. Seed coat color can vary greatly and impact the antioxidant capacity of the edible portion of the peanut. Additionally, the seed coat can provide bitter notes in products, affecting their palatability and potentially negating the beneficial properties of the antioxidants present. A total of 42 accessions from the Germplasm Resource Information Network (GRIN) with a variety of seed coat colors were obtained and analyzed for total antioxidant capacity to provide a baseline assessment of the distribution of antioxidants in kernel versus seed coats. The results demonstrated that seed coat color somewhat impacts antioxidant capacity, and 56-88% of the total antioxidant capacity resides in the seed kernel. Three control samples, not part of the germplasm collection, were roasted and prepared for analysis by the descriptive sensory panel. Seed coats were added back to the roasted paste in increasing proportion for analysis by the panel, and perceptions regarding bitterness and overall organoleptic properties were noted. Based on the results of this study, several accessions were selected and then planted for increase and potential crossbreeding with appropriate commercial cultivars. This information could be used to selectively add antioxidant capacity to peanut breeding programs to provide additional health benefits to consumers without compromising the sensory perception and desirability and peanut products in nutrition.