Maximizing the Extraction of Bioactive Compounds from Diospyros kaki Peel through the Use of a Pulsed Electric Field and Ultrasound Extraction

The persimmon fruit (Diospyros kaki Thunb.) is renowned for its exceptional health benefits, which can be attributed to its abundance of bioactive compounds. This study aimed to optimize the extraction of bioactive compounds from persimmon peel, an underexplored waste biomass, within the frame of sustainability and a circular economy. For this reason, a comprehensive multi-factor extraction approach was employed. Specifically, diverse methods including a pulsed electric field and ultrasonication combined with simple stirring were explored. Through this systematic approach, the most efficient extraction process was determined, resulting in elevated yields of bioactive compounds, including polyphenols, ascorbic acid, and total carotenoids. Among the identified phenolic compounds, rutin emerged as the most abundant, with concentrations reaching up to 172.86 μg/g. Utilizing partial least squares analysis, the maximum predicted values for the bioactive compounds were determined, with total polyphenols reaching 7.17 mg GAE/g, ascorbic acid at 4.93 mg/g, and total carotenoids at 386.47 μg CtE/g. The antioxidant activity of the extracts was evaluated with the ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, and H2O2 scavenging assays. The recorded antioxidant performance underscored the substantial potential of persimmon peels as a source of cost-effective extracts with high antioxidant activity. This study not only contributes to optimizing the bioactive compounds’ extraction from persimmon peel but also highlights the process’s viability by producing valuable extracts with antioxidant properties at low cost.