Food fortification may be carried out to improve the health status of consumers. In this study, peanut skins were added at 1.3, 1.8, and 2.5% to cookies to increase their polyphenol content. Insoluble fiber was increased by up to 52%. In addition, total phenolic content and the corresponding antioxidant capacities also increased as evidenced by increases of epicatechin and procyanidin dimers A and B. In addition, trimers and tetramers of procyanidins were identified only in peanut skin-fortified cookies. Addition of 2.5% peanut skins rendered an increase of up to 30% in the total polyphenols as evaluated by high-performance liquid chromatography-diode array detection-electrospray ionization multistage mass spectrometry (HPLC-DAD-ESI-MS(n)). Sensory evaluation results demonstrated that peanut skin-fortified cookies were well accepted, which suggests that the present formulation may lend itself for commercial exploitation.
Keywords: byproduct; fiber; moisture; polyphenol; proanthocyanidin.