Preparation of Enzymatic Co-modified Cyperus esculentus Starch and Its Effect on the Construction of Starch-based Double Emulsion System

To overcome the application limitations of natural jatropha starch, such as susceptibility to aging and poor solubility and stability, this study employed composite enzyme (EMD) synergistic medium grinding treatment (M-EMD), high-pressure homogenization treatment (H-EMD), nano-precipitation (N-EMD) modification techniques to enhance oilseed starch. The modified starch was then incorporated into starch-based double emulsion systems to evaluate its effects on interfacial tension, stability, and the in vitro digestion of lycopene-loaded emulsions. Results indicated that the modification effects of different synergistic modification methods on starch were significantly different. N-EMD treatment demonstrated optimal performance, yielding starch particles with the smallest size (0.797 μm), the most uniform distribution (PDI=0.19), the highest surface negative charge (Zeta potential=−70 mV), and the strongest hydrophilicity (contact angle=23.1°). Structural analysis revealed that both H-EMD and N-EMD treatments effectively induced starch molecular restructuring. The double emulsion droplets constructed from N-EMD starch were fine, uniform, and structurally regular, exhibiting the highest lycopene encapsulation efficiency (88%) and loading capacity (66%). During storage, this emulsion exhibited the optimal physical stability and minimal lipid oxidation. In simulated in vitro digestion, its free fatty acid release rate (45%) and Lyc bioavailability (48%) significantly surpassed other groups. In conclusion, enzyme-assisted nano-precipitation (N-EMD) represented the most effective strategy for optimizing oil palm starch properties and constructing efficient starch-based delivery systems. This study pioneers new pathways for high-value utilization of jatropha starch and provides theoretical foundations and technical references for developing high-performance food-grade delivery carriers for bioactive compounds.