Abstract:
To achieve efficient extraction of paprika red pigment, this study utilized dried peppers of Xinjiang ‘Hong long 23’ as the raw material and employed response surface methodology (RSM) combined with random centroid optimization (RCO) to optimize the extraction process using atmospheric pressure plasma jet (APPJ) pre-treatment coupled with a high-voltage electric field (HEF). The extraction yield and color value of paprika red pigment were used as evaluation indicators. To investigate the mechanisms behind efficiency improvements, different extraction techniques (conventional solvent extraction, CK; atmospheric pressure plasma jet, APPJ; pulsed electric field, HEF; and a combined APPJ+HEF approach) were applied to recover red pigments from paprika. The extracted pigment content was measured via High-performance liquid chromatography (HPLC). Subsequently, scanning electron microscopy (SEM) and water contact angle analysis were employed to examine microstructural changes and surface hydrophilicity of the treated biomass, respectively. The optimal extraction process for paprika red pigment using the combined APPJ+HEF approach was determined as follows: Plasma pretreatment voltage of 3.5 kV, jet duration of 20 s, jet distance of 5.5 cm, solid-to-liquid ratio of 1:20 (g/mL), electric field intensity of 20 kV, and treatment time of 2 min. Under these conditions, the extraction yield of paprika red pigment reached 38.77%, with a color value of 187.23, representing increases of 70.93% and 87.49%, respectively, compared to the control (CK) group (
P<0.05). Furthermore, the pigment content in the APPJ+HEF-treated group was significantly higher than that in the CK, HEF, and APPJ alone groups (
P<0.05). SEM and contact angle analysis revealed that the APPJ+HEF treatment resulted in the most severe disruption of the cell wall and the highest hydrophilicity, indicating that the extraction efficiency of paprika red pigment is closely related to the degree of cellular structure destruction. This study provides new technical support for the green and efficient extraction and application of paprika red pigment and other bioactive components.