Preparation and digestive characteristics of a novel soybean lipophilic protein-hydroxypropyl methylcellulose-calcium chloride thermosensitive emulsion gel

This study describes the preparation, physicochemical characterization, and nutrient release behavior analysis during the in vitro digestion of a soybean lipophilic protein-hydroxypropyl methylcellulose-calcium chloride (LHC-Ca) thermosensitive emulsion gel. Infrared spectroscopy, X-ray diffraction (XRD), and 1H NMR spectra showed that CaCl2 addition changed the crystallinity of HPMC and reduced its hydrogen content, thereby lowering its emulsion gel temperature significantly. Microstructure and rheology showed that CaCl2 addition effectively altered LHC-Ca's fundamental structure and interface characteristics. The ideal LHC-Ca performances were achieved using 0.3 M CaCl2. Simulated in vitro digestion experiments replicated the targeted release of vitamin E in the intestine and higher bioaccessibility. These findings may help develop a functional thermosensitive emulsion gel carrier based on a lipophilic-hydroxypropyl methylcellulose (LP-HPMC) emulsion for targeted and sustained release of nutrients.