Jujube (Ziziphus jujuba Mill.) fruit is an important medicinal plant in Turkey. Several characteristics of jujube fruit harvested at four maturation stages were evaluated. The maturation stages were classified by degree (%) of dark color formation on the fruit surface [Stage (S1), 1–10% (S2), 11–50% (S3), 51–100% (S4)]. Fruit weight, width, length, stone weight, flesh/stone ratio, total soluble solids (TSS), titratable acidity (TA), organic acids and specific sugars were determined. Total phenolic content (TPC) was measured along with antioxidant activity (AOC), determined by Ferric Reducing Ability of Plasma (FRAP) and Trolox Equivalent Antioxidant Capacity (TEAC). Results of the study showed that TSS increased from 12.8% to 18.3% from the S1 to the S4 fruit stage, respectively. The S3 had the highest TPC (6518 mg GAE·kg fw). The highest AOC were recovered from S2 (TEAC; 74.4 µmol TE·g fw, FRAP; 50.9 µmol TE·g fw), followed by S3 (TEAC; 63.6 µmol TE·g fw, FRAP; 37.6 µmol TE·g fw). The main organic acid was citric acid as determined by the HPLC method. Fructose content tended to be more stable than glucose or sucrose.

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