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 Escherichia coli and Staphylococcus aureus. 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.