Peanut skin powder as a functional ingredient in cracker making: Effects on quality attributes, antioxidant properties and predicted glycemic index

This study investigated the potential of incorporating peanut skin powder (PSP) as a partial substitute for wheat flour in cracker formulations, with particular emphasis on how PSP-induced matrix changes affect functional properties of the supplemented crackers. Supplementation with PSP in the range of 0−16% increased total dietary fiber content up to 5.1-fold and total phenolic content by 3.4-fold while enhancing antioxidant capacity by 13−14-fold. Furthermore, PSP fortification reduced the predicted glycemic index (pGI), with values decreasing from 55.5 to 48.8 at 16% substitution. However, increasing PSP levels led to changes in textural properties, with progressive increases in hardness and fracturability, accompanied by a decline in overall acceptability at 8% PSP substitution or higher ratio. Although the amount of phenolics released during in vitro digestion increased, their bioaccessibility decreased from 76.4% in the control to 57.0% at 16% PSP substitution, likely due to entrapment within the fiber-rich matrix. At 8% PSP substitution, crackers achieved a favorable balance, showing an 87.0% increase in released phenolics, while maintaining acceptable sensory quality and meeting the criteria for high-fiber and low-pGI foods. These results indicate a trade-off in which structural modifications within the cracker matrix concurrently starch digestibility (reflected in pGI) the bioaccessibility of intergrated phenolics, hence determining their final functional availability. • Peanut skin powder PSP enhances fiber level and antioxidant activities of crackers • 8% PSP-added crackers meet high-fiber criteria with minimal sensory impact • PSP lowers predicted glycemic index of wheat crackers • PSP alters cracker texture and limits phenolic bioaccessibility • PSP can be reused as a functional ingredient in cracker making