Controlled release network hydrogel based on zein/sodium alginate-stabilized chrysanthemum essential oil Pickering emulsions for prolonged preservation of fresh-cut Gastrodia elata.
Abstract
Browning and microbial proliferation are major factors driving quality deterioration in fresh-cut Gastrodia elata. This study developed a zein/sodium alginate-stabilized chrysanthemum essential oil (CEO) Pickering emulsion and incorporated it into gelatin-konjac glucomannan hydrogels for fresh-cut G. elata preservation. The emulsion exhibited nanoscale droplets (194.53-515.00 nm) with exceptional stability (zeta potential: -82.85 to -95.92 mV), confirming effective encapsulation of CEO. The optimized hydrogel (GK-8%) formed a dense network with uniform pore structure, demonstrating superior water retention and sustained release properties, achieving 73.30% CEO release over 390 h. Application tests revealed that GK-8% significantly reduced weight loss (≤ 0.15%) and browning index (26.72% reduction), maintained firmness and total phenolic content, while decreasing antioxidant enzyme activities, indicating reduced oxidative stress. Visual observations showed that GK-8% treatment delayed visible browning by approximately 3 days compared to the control. The hydrogel extended shelf life through synergistic effects of microbial inhibition and oxidative stress alleviation, providing an effective, eco-friendly strategy for fresh-cut product preservation.