Investigating the Antioxidant Potential of Mango Seed Kernel Polyphenols: Extraction and Optimization Strategies

Mango seed kernels, an underutilized by-product of the mango pulping industries, are a rich supplier of metabolites, specifically phenolic and flavonoid compounds. These compounds have potential health benefits. The present study aims to optimize the solvent-assisted conditions for polyphenol extraction from mango seed kernels by using the Box-Behnken design (BBD) and response surface methodology (RSM). Moreover, the effect of the solvent-to-solid ratio (5:1 to 25:1, mL/g), extraction temperature (30-70 °C), and extraction time (60-120 min) on the polyphenol yield was investigated. The optimal conditions of a solvent-to-solid ratio of 12 (mL/g), extraction temperature of 53 °C, and extraction time of 97 min showed the maximum yield of dried extract. In optimal conditions, the extract contained a total phenolic content of 110.02 ± 0.50 mg gallic acid equivalent (GAE)/g, total flavonoids of 24.58 ± 0.09 mg quercetin equivalent (QE)/g, 64.21 ± 0.12% inhibition of DPPH, and 53.25 ± 0.23% ABTS radical scavenging. Moreover, the extract at 500 mg/mL concentration showed the highest anti-bacterial activity against pathogenic bacteria of <i>Escherichia coli</i> and <i>Staphylococcus aureus</i>. Gallic acid, mangiferin, rutin, ferulic acid, cinnamic acid, and quercetin were noted in mango seed kernel extract obtained at optimal extraction conditions. Overall, a rapid and optimal methodology is reported for extracting, identifying, and quantifying polyphenols from mango seed kernels.