Peach gum polysaccharide (PGP), a natural biopolymer extracted from the resin of the peach tree, holds significant potential for applications in food, cosmetics, and pharmaceutical industries. However, detailed analysis and exploration of its physical and chemical properties remain limited. This study investigates the physicochemical properties, rheological behavior and emulsion stability of PGPs extracted using thermal (TPGP) and enzymatic (EPGP) methods. The results indicate that both polysaccharide fractions exhibit similar arabinogalactan (AG) structures, with high contents of arabinose and xylose, as evidenced by FTIR spectra and monosaccharide composition. However, high-performance size-exclusion chromatography (HPSEC) revealed differences in molecular weights and chain conformations, leading to distinct rheological behaviors. PGP solutions exhibited pseudoplastic flow behavior, with TPGP demonstrating higher viscosity due to its larger molecular weight (1.295 × 10⁷ g mol⁻¹). As the PGP concentration increased, gel strength and emulsion stability improved significantly. This study provides more insight into the rheological and emulsifying characteristics of PGPs extracted by varied methods, facilitating their potential applications in food industries.

Ultraviolet (UV) absorbents have been used in sunscreen products in the cosmetic industry, showing adverse effects like rising skin irritation and huge toxicological risks. Although nanostructured lipid carriers (NLCs) are regarded as the potential delivery systems for increasing the amount of encapsulated sunscreen agents and playing UV synergistic effect, the overall synergistic ability is insufficient to meet the industrial demand. In the current study, we optimized a new type of sunscreen composite carrier formulation, the SiO₂-NLC nanocomposites carrying ethyl methoxycinnamate (OMC) (OMC/SiO₂-NLC), describing their features and functional performance. The OMC/SiO₂-NLC nanocomposites are emerging sunscreen systems for cosmetic applications, which combine the advantages of both SiO₂ and NLCs. The OMC/SiO₂-NLC products, as compared to the ordinary cosmetic emulsion, were characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscope, and UV spectrophotometer. In addition, the nanocomposites were also tested for safety and functional properties. The results showed that the OMC/SiO₂-NLC particles could effectively encapsulate the sunscreen, in which the encapsulation efficiency reached 76%. The UV absorbance value of the OMC/SiO₂-NLC composite carrier containing the same amount of OMC was significantly increased compared with OMC/NLC. The composite carrier's sun protection factor (SPF) increased 56.7%. Photostability of the OMC/SiO₂-NLC particles maintained stability for more than 10 hours under UV radiations. The SiO₂-based nanocomposites showed better biocompatibility and UV synergistic performance. Therefore, the optimized composite carrier was a suitable nanocomposite for cosmetic applications. GRAPHICAL ABSTRACT

In this study, we investigated the effects of different hydrogen bond types on the photophysical properties of diethylamino hydroxybenzoyl hexyl benzoate (DHHB) by systematically exploring the changes in the spectral properties of DHHB in protic and aprotic solvents. The formation and stability of hydrogen bonds were also studied, demonstrating that the system mainly existed in the form of intramolecular hydrogen bonds at low concentrations (≤5 μg/mL). In these circumstances, the fluorescent intensity, and molar absorption coefficient changed little, indicating that the intramolecular hydrogen bonds had little effect on the spectral properties of DHHB. With an increase in concentration, the number of intermolecular hydrogen bonds increased and the molar absorption coefficient significantly increased, indicating that the intermolecular hydrogen bonds were conducive to improving the UV absorption properties of DHHB. With an increase in temperature, the molar absorption coefficient of the system decreased, which reduced the UV absorption performance of DHHB. In the protic solvent, the system also contained DHHB–solvent intermolecular hydrogen bonds. With an increase in the proportion of protic solvent in the system, the fluorescent intensity of the system significantly decreased, and the UV integral area significantly increased, indicating that the hydrogen bond between DHHB and the solvent molecules was beneficial in terms of improving the UV absorption performance of DHHB.