Purpose: This study aimed to improve the antioxidant activities of sweet persimmon peel extracts using supercritical carbon dioxide (SFE-CO2 ) as a green extraction (GE) technology, as part of upcycling efforts. It also aimed to demonstrate the effectiveness of GE as an ecofriendly extraction method by comparing it with conventional extraction (CE) techniques. Methods: Sweet persimmon peel extracts were obtained using CE (hot water at 80°C for 6 h or 95% ethanol at room temperature for 24 hours) and SFE-CO2 extraction (50°C for 2 hours, with pressures ranging from 100 to 250 bar). Antioxidant activities (2,2-diphenyl-1-picrylhydrazyl [DPPH] radical scavenging activity and tannin content) were analyzed to evaluate and compare the antioxidant extraction efficiency across different extraction methods. Results: In the CE extraction method, the 95% ethanol extract exhibited 1.2 times higher DPPH radical scavenging activity and 1.5 times higher tannin content than that of the hot water extract. In the SFE-CO2 extraction method, antioxidant activities increased with increasing pressure (100–250 bar), as higher pressures enhanced antioxidant activities and extraction efficiency. At 250 bar, the SFE-CO2 extracts demonstrated 1.6 times higher DPPH radical scavenging activity and 2.0 times higher tannin content than that of the hot water extract, and 1.3 times higher DPPH scavenging activity and tannin content than that of the 95% ethanol extract. These findings highlight the superior efficiency of extraction using the SFE-CO2 method. Conclusion This study demonstrated that SFE-CO2 was an efficient and eco-friendly method for extracting antioxidants from sweet persimmon peels, surpassing conventional methods.It underscores the potential of SFE-CO2 for the sustainable upcycling of sweet persimmon byproducts and the promotion of green technologies to enhance antioxidant activities.

Purpose: This study aimed to improve the antioxidant activities of sweet persimmon peel extracts using supercritical carbon dioxide (SFE-CO2 ) as a green extraction (GE) technology, as part of upcycling efforts. It also aimed to demonstrate the effectiveness of GE as an ecofriendly extraction method by comparing it with conventional extraction (CE) techniques. Methods: Sweet persimmon peel extracts were obtained using CE (hot water at 80°C for 6 h or 95% ethanol at room temperature for 24 hours) and SFE-CO2 extraction (50°C for 2 hours, with pressures ranging from 100 to 250 bar). Antioxidant activities (2,2-diphenyl-1-picrylhydrazyl [DPPH] radical scavenging activity and tannin content) were analyzed to evaluate and compare the antioxidant extraction efficiency across different extraction methods. Results: In the CE extraction method, the 95% ethanol extract exhibited 1.2 times higher DPPH radical scavenging activity and 1.5 times higher tannin content than that of the hot water extract. In the SFE-CO2 extraction method, antioxidant activities increased with increasing pressure (100–250 bar), as higher pressures enhanced antioxidant activities and extraction efficiency. At 250 bar, the SFE-CO2 extracts demonstrated 1.6 times higher DPPH radical scavenging activity and 2.0 times higher tannin content than that of the hot water extract, and 1.3 times higher DPPH scavenging activity and tannin content than that of the 95% ethanol extract. These findings highlight the superior efficiency of extraction using the SFE-CO2 method. Conclusion This study demonstrated that SFE-CO2 was an efficient and eco-friendly method for extracting antioxidants from sweet persimmon peels, surpassing conventional methods.It underscores the potential of SFE-CO2 for the sustainable upcycling of sweet persimmon byproducts and the promotion of green technologies to enhance antioxidant activities.

Purpose: This study aimed to improve the antioxidant activities of sweet persimmon peel extracts using supercritical carbon dioxide (SFE-CO2 ) as a green extraction (GE) technology, as part of upcycling efforts. It also aimed to demonstrate the effectiveness of GE as an ecofriendly extraction method by comparing it with conventional extraction (CE) techniques. Methods: Sweet persimmon peel extracts were obtained using CE (hot water at 80°C for 6 h or 95% ethanol at room temperature for 24 hours) and SFE-CO2 extraction (50°C for 2 hours, with pressures ranging from 100 to 250 bar). Antioxidant activities (2,2-diphenyl-1-picrylhydrazyl [DPPH] radical scavenging activity and tannin content) were analyzed to evaluate and compare the antioxidant extraction efficiency across different extraction methods. Results: In the CE extraction method, the 95% ethanol extract exhibited 1.2 times higher DPPH radical scavenging activity and 1.5 times higher tannin content than that of the hot water extract. In the SFE-CO2 extraction method, antioxidant activities increased with increasing pressure (100–250 bar), as higher pressures enhanced antioxidant activities and extraction efficiency. At 250 bar, the SFE-CO2 extracts demonstrated 1.6 times higher DPPH radical scavenging activity and 2.0 times higher tannin content than that of the hot water extract, and 1.3 times higher DPPH scavenging activity and tannin content than that of the 95% ethanol extract. These findings highlight the superior efficiency of extraction using the SFE-CO2 method. Conclusion This study demonstrated that SFE-CO2 was an efficient and eco-friendly method for extracting antioxidants from sweet persimmon peels, surpassing conventional methods.It underscores the potential of SFE-CO2 for the sustainable upcycling of sweet persimmon byproducts and the promotion of green technologies to enhance antioxidant activities.