In this study, subcritical water was used to crosslink gelatin and alginate (G/A) at different temperatures (120 °C, 130 °C, 140 °C, 150 °C, and 160 °C) under constant pressure and reaction time (3 MPa, 30 min). Structural and morphological characterization was performed using Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), nuclear magnetic resonance spectroscopy (¹H NMR), and scanning electron microscopy (SEM). The coffee oil-filled hydrogels were prepared using G/A blend by ultrasound sonication. The emulsions revealed a unimodal distribution of particles with varying diameters (654 ± 98) nm, (509 ± 44) nm, and (412 ± 68) nm for G/A at 120 °C, 130 °C and 140 °C, respectively. However, the treatment of G/A at 150 °C and 160 °C resulted in bimodal size distribution and declined viscosity, and indicated the molecular degradation of hydrogels leading to weak repulsion force against droplet aggregation. Highly stable emulsions were observed from G/A at (120–140) °C, while at 150 °C and 160 °C, the emulsion exhibited poor stability during 7 weeks of storage at 5 °C and 25 °C.

在这项研究中，亚临界水用于在恒定压力和反应时间（120°C，130°C，140°C，150°C和160°C）下在不同温度（120°C，130°C，140°C，150°C和160°C）交联明胶和藻酸盐（G / A）。 3 MPa，30分钟）。使用傅里叶变换红外光谱（FT-IR），X射线衍射（XRD）和核磁共振光谱进行结构和形态表征（¹1 H NMR）和扫描电子显微镜（SEM）。使用G / A共混物通过超声处理来制备填充咖啡油的水凝胶。乳剂在120°C，130°C和140°C下的G / A分别显示直径（654±98）nm，（509±44）nm和（412±68）nm的颗粒的单峰分布。但是，在150°C和160°C下处理G / A会导致双峰尺寸分布和粘度下降，并表明水凝胶的分子降解导致对液滴聚集的排斥力较弱。在（120–140）°C下从G / A观察到高度稳定的乳液，而在150°C和160°C下，该乳液在5°C和25°C的存储7周内表现出较差的稳定性。