Panax japonicus and Dioscorea deltoidea Cell Cultures as a Source of Stable Antioxidant Food Components

Suspension cell cultures of Panax japonicus and Dioscorea deltoidea are promising sources of plant-derived antioxidant compounds. In this study, aqueous-ethanolic extracts from these cultures were immobilized with maltodextrin and converted into powders by freeze-drying and spray-drying. Antioxidant potential, chemiluminescence kinetic profiles, phytochemical composition, powder properties, and storage stability were evaluated. UPLC-ESI-MS confirmed characteristic metabolites, including ginsenosides in P. japonicus and steroidal glycosides in D. deltoidea. Drying affected antioxidant properties in a species- and assay-dependent manner. Spray-drying increased TAC_FRAP and TAC_DPPH in both species, whereas freeze-drying resulted in higher TAC_ORAC, particularly in P. japonicus, where the value exceeded that of the spray-dried powder by 96.0% (p < 0.05). In contrast, spray-dried D. deltoidea showed higher TAC_FRAP, TAC_DPPH, and total phenolic compounds than the freeze-dried powder. Chemiluminescence analysis provided additional kinetic information: freeze-dried P. japonicus retained antioxidant-related effects over the widest dilution range, whereas spray-dried D. deltoidea showed a kinetic profile closer to the native extract. After 6 months, spray-dried P. japonicus retained the highest absolute TAC values, while for D. deltoidea, drying method selection depended on the target antioxidant property. These results support maltodextrin-based drying for obtaining water-dispersible antioxidant powders for food systems.