Apple Vis-NIR Spectral Dataset for SSC Prediction Across Origins and Years (2018-2019, 2025)

Visible and near-infrared (Vis-NIR) spectral measurements and soluble solids content (SSC, degree Brix) reference values for Red Fuji apples collected from four major Chinese production regions (Xinjiang, Shandong, Shaanxi, Gansu) across three harvest years (2018, 2019, 2025). Data include 1,888 apple samples with 5-position intra-fruit SSC measurements. Two spectrometers were used: Ocean Optics USB2000+ (2018-2019, 590-1200 nm) and a push-broom hyperspectral imaging system (2025, 391-1001 nm). SSC was measured using an ATAGO PR-101alpha digital refractometer with automatic temperature compensation.