Objective In response to the lack of objective standards for the nine-steaming and nine-drying process of Huangjing (Polygonati Rhizoma), this study quantified the dynamic changes in traits and components during processing, combined with zebrafish antioxidant activity experiments, to identify the optimal stage for comprehensive quality and provide a scientific basis for establishing modern quality control methods. Methods Using the decoction pieces of Polygonatum cyrtonema as the object of study, a colorimeter, texture analyzer, and electronic tongue were employed to quantify the color, texture, and taste of samples from different steaming cycles (S0—S9). Polysaccharide content, reducing sugars and amino acids was determined by UV-Vis, while 5-hydroxymethylfurfural (5-HMF) were measured using HPLC. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) were used to identify patterns in the processing stages. Pearson correlation analysis, the CRITIC objective weighting method, and zebrafish antioxidant experiments were integrated for comprehensive evaluation. Results As steaming progressed, color parameters (E_ab^*, L^* and b^*) continuously decreased, texture parameters (hardness, chewiness, gumminess) significantly declined, and moisture content increased. In terms of taste, bitterness and astringency markedly decreased by the third steaming cycle (S3), while sweetness increased. Chemically, 5-HMF accumulated continuously, reducing sugars peaked at S3 (1.38%), and amino acid and polysaccharide contents stabilized after S3. The correlation network analysis revealed significant relationships among trait indicators, chemical components, and bioactivity (P < 0.05). Multivariate statistical analysis divided the processing into three stages, with the early stage (S1—S3) identified as the critical transition period for quality formation. The comprehensive evaluation using the Criteria importance through intercriteria correlation method indicated that sample S3 achieved the highest overall quality score (65.41). At this stage, the sample was characterized by moderate 5-HMF accumulation, peak reducing sugar conten, and and maintenance of amino acids at a high level. It exhibited blackish-brown color (a^* was 11.13), with a soft and flexible texture (springiness was 0.647), and a disappearance of the numbing sensation. Its taste was sweet with slight bitterness (sweetness value was 4.50, bitterness value was 5.55), accompanied by a significantly enhanced antioxidant capacity. Conclusion This study establishes the third steaming cycle (S3) as the optimized processing endpoint for the nine-steaming and nine-drying process of P. cyrtonema and established amulti-dimensional quantifiable quality control system centered on “appearance properties-intrinsic components-bioactivity”. These findings provide a scientific basis for the standardization and precise quality control of this processing method.

Polygonatum cyrtonema Hua  /  nine-steaming and nine-drying process  /  processing endpoint determination  /  multi-dimensional quantification  /  quality control  /  antioxidant activity  /  color  /  texture  /  taste  /  polysaccharide  /  reducing sugar  /  amino acids  /  5- hydroxymethylfurfural  /  hierarchical cluster analysis  /  principal component analysis  /  CRITIC weight analysis method