Optimization of Processing Technology for Sophora japonica Based on Multi-Component Control and Color Correlation Analysis
This study optimized the processing parameters for two distinct preparations of Sophora japonica (SJ) — stir-fried SJ and charred SJ — using a multi-component quantification and color-correlation framework. Nine marker compounds (5-hydroxymethylfurfural, protocatechuic acid, rutin, isoquercitrin, quercetin, kaempferol-3-O-rutinoside, narcissin, kaempferol, and isorhamnetin) plus alcohol-soluble extract content were quantified by UPLC. A Box-Behnken design-response surface methodology (BBD-RSM) evaluated roasting power, roasting time, and feedstock quantity. CRITIC weighting assigned objective coefficients to the ten indicators. An IRIS electronic eye captured color values (L*, a*, b*), and correlations with chemical markers were analyzed using SPSS 20.0 and Origin 2024. The optimal stir-fried SJ conditions were 900 W, 5.5 min, and 115 g, yielding a composite score of 67.33 (RSD 2.29%). For charred SJ, 1,600 W, 3 min, and 100 g produced a score of 78.98 (RSD 0.70%). Validation across three batches confirmed process stability. Color-component correlation revealed that L* and b* were significantly positively correlated with rutin, kaempferol-3-O-rutinoside, and narcissin, and negatively correlated with kaempferol, quercetin, and isorhamnetin. The a* value was positively correlated with protocatechuic acid, isoquercitrin, quercetin, kaempferol, and isorhamnetin. These findings establish a quantitative color-based control strategy for SJ processing, linking visual appearance to hemostatic pharmacodynamics and offering a practical tool for quality assessment and clinical application.