Nutritional and bioactive profiles of daylily (Hemerocallis citrina) across flowering stages: A framework for strategic harvest timing

This study evaluated the impact of different flowering stages on the quality attributes of daylily ( Hemerocallis citrina Baroni) flowers. Analysis of samples from three flowering stages (initial, full bloom, and final) revealed distinct biochemical profiles that provide a framework for optimizing harvest timing. The initial flowering stage showed the highest concentrations of multiple compounds. These included phenolics (6.2±0.6 mg/g DW), flavonoids (1.55±0.01 mg/g DW), calcium (3078±1 μg/g DW), and total sugars (190±1 mg/g DW). Full bloom stage exhibited peak concentrations of amino acids (41.05±0.01 mg/g DW), potassium (1982±3 μg/g DW), and magnesium (1392±3 μg/g DW). Phenolic compounds showed U-shaped distribution, decreasing at full bloom before partially recovering during final flowering. Multivariate analysis revealed complex metabolic networks with strong correlations between phenolics and antioxidant activities. OPLS-DA (R 2 X=0.95) clearly distinguished distinct metabolic profiles characteristic of each flowering stage. The antagonistic positioning of parameters in the OPLS-DA biplot aligned with negative correlations in the heatmap, confirming metabolic trade-offs throughout development. These findings provide a framework for strategic harvesting: initial flowering maximizes antioxidant properties, full bloom optimizes nutritional content, and final flowering enhances specific flavor compounds, enabling evidence-based decisions to maximize both nutritional value and economic potential. • Biochemical profiles revealed distinct metabolic signatures across daylily stages. • Stage-specific variations in nutrients, minerals, and bioactives were evaluated. • Polyphenols and antioxidants showed U-shaped patterns during flower development. • Strategic harvest timing optimizes nutritional value and economic potential.