Comprehensive Phenolic Profiling and Antioxidant Evaluation of Calyx, Rind, and Edible Tissues From Non‐Astringent Persimmons ( Diospyros kaki )

ABSTRACT Persimmon ( Diospyros kaki L.) processing generates substantial quantitiesof underutilized by‐products despite their richness in bioactive compounds. This study evaluated the phenolic content, antioxidant potential, and phytochemical composition of four tissues (calyx, rind, pulp, inner pulp) from two non‐astringent cultivars, namely, Fuyu and Jiro. Phenolic estimation (TPC, TFC, and TTC) and seven antioxidant assays (DPPH, ABTS + , ·OH‐RSA, FRAP, RPA, TAC, and FICA) revealed strong tissue‐specific variation. Calyx tissues displayed the highest phenolic concentrations and antioxidant activities, with Fuyu calyx showing the greatest TPC (38.98 mg GAE/g DW) and TTC (46.32 mg CE/g). Edible tissues exhibited substantially lower values, consistent with tannin insolubilization during ripening. Pearson's correlations showed strong associations between TPC/TFC and all antioxidant assays ( r = 0.985−0.999), except FICA, which demonstrated weak negative correlations, highlighting method limitations for metal‐chelating evaluation in persimmon matrices. LC‐ESI‐QTOF‐MS/MS profiling identified 95 phenolic compounds across samples, including hydroxybenzoic acids, hydroxycinnamic acids, flavonoids, lignans, and stilbenes, with calyx tissues containing the greatest diversity. HPLC‐DAD quantification confirmed gallic acid, catechin hydrate, and sinapic acid as key compounds, detected in Fuyu calyx. Overall, persimmon calyx represents a potent source of antioxidant phenolics with strong potential for valorization in functional food and nutraceutical applications.