In this study, sodium alginate–chitosan composite microspheres (S-C Ms) were prepared by ionic gelation to encapsulate Ziziphus jujuba pulp from wild jujube pulp. The effects of sodium alginate (SA) concentration, chitosan (CS) concentration, and core-to-wall ratio on encapsulation efficiency (EE%) and loading capacity (LC%) were systematically investigated. The results showed that both EE% and LC% were maximized when the SA concentration was 2.0% (w/v) and the CS concentration was 1.5% (w/v). The FTIR and XRD analyses confirmed the successful encapsulation of a phenolic-rich extract from Z. jujuba pulp (PRE) and its transformation into an amorphous state, while the SEM observations revealed that the composite microspheres possessed a well-defined morphology and a dense internal structure. Particle size analysis further indicated a narrow and uniform size distribution. Thermogravimetric analysis (TGA) and in vitro simulated digestion demonstrated that S-C Ms exhibited a pH-responsive release profile, characterized by slow, limited release in the gastric phase and markedly enhanced release in the intestinal phase. The release mechanism in simulated gastric fluid was dominated by Fickian diffusion, whereas it shifted to an erosion-controlled process in simulated intestinal fluid. Consistently, the swelling ratio of the microspheres was low at pH 1.2 but increased sharply at pH 7.0, reflecting a “gastric protection–intestinal release” behavior. Antibacterial assays showed that P-loaded microspheres exerted significant inhibitory effects against Staphylococcus aureus and other test strains, with the antibacterial activity possibly associated with the controlled release during the in vitro digestion of compounds with antimicrobial potential, such as phenolic compounds. Overall, SA-CS composite microspheres exhibited favorable encapsulation performance, structural stability, and controlled-release potential, making them a promising delivery and protection system for Ziziphus jujube pulp bioactive compounds.

To address the challenge of purifying bioactive polyphenols from the complex matrix of Ziziphus jujuba Mill. var. spinosa pulp, this study established an integrated purification protocol combining Deep Eutectic Solvent (DES) extraction with macroporous adsorption resin (MAR) enrichment. Among five screened resins, AB-8 exhibited superior selectivity, achieving a maximum adsorption capacity of 62.48 mg polyphenols/g dry resin and a desorption ratio of 83.40%. Kinetic analysis revealed that the adsorption process strictly followed a pseudo-second-order model (R² = 0.999), indicating a mechanism dominated by chemisorption. Through dynamic optimization, optimal column parameters were determined as a loading concentration of 2.4 mg/mL, a flow rate of 1.0 mL/min, and elution with 70% (v/v) ethanol. Structural characterization via UV-Vis and FT-IR confirmed the effective removal of polysaccharide and protein impurities, while High-Performance Gel Permeation Chromatography (HPGPC) indicated a low-molecular-weight distribution (M_w approx. 1073 Da). Furthermore, HPLC-MS profiling definitively identified eight key constituents, including chlorogenic acid, catechin, rutin, and quercetin. Collectively, this work elucidates the adsorption mechanism and provides a scalable, efficient technical foundation for the high-purity preparation of jujube polyphenols.

Insomnia remains a widespread global health issue, and traditional hypnotic drugs often produce adverse effects. Although spinosin in Ziziphi Spinosae Semen has sleep-promoting effects, its use is limited by poor solubility and low oral bioavailability. In this study, the solvent melt method was used to prepare spinosin solid dispersions, optimising the process with an L₉(3⁴) orthogonal design based on apparent solubility. In vitro dissolution testing showed that solid dispersions of varying particle sizes dissolved more readily than pure spinosin, with smaller particles exhibiting faster dissolution. Cellular uptake was assessed in human colon adenocarcinoma cells, with results revealing enhanced uptake of smaller-particle solid dispersions. Powder X-ray diffraction confirmed that spinosin transformed from a crystalline to an amorphous state in the dispersion system. A quadratic orthogonal experiment was conducted to optimise functional dairy beverage formulation, using the centrifugal sedimentation rate as the evaluation index. In vivo experiments demonstrated that the resulting functional dairy beverage reduced spontaneous activity in mice, achieved a 60% sleep-onset rate, improved ethanol-induced memory impairment and produced marked sleep-promoting effects. Moreover, pharmacokinetic studies confirmed that the spinosin solid-dispersion-based functional dairy beverage significantly enhanced the systemic exposure and oral bioavailability of spinosin compared to the spinosin water suspension. These findings indicate that solid dispersion technology effectively enhances spinosin solubility and that the developed functional dairy beverage shows promise as a sleep-promoting functional food.