Polyphenol-enriched Sophora japonica L. and Rosa rugosa Thunb. composite solid beverage: antioxidant and lipid-lowering efficacy with stability assessment

Abstract

In the context of a surging demand for functional foods, this study utilized Sophora japonica L. (SL) and Rosa rugosa Thunb. (RT), which are rich in polyphenols (with flavonoids as the core subclass). High-purity extracts (SLE and RTE) were obtained through ethanol reflux extraction and macroporous resin purification, and then formulated with maltodextrin and erythritol to prepare a composite solid beverage. This beverage exhibited excellent antioxidant capabilities. At a concentration of 1 mg/mL, the scavenging rates of DPPH, ABTS, and hydroxyl radicals reached 82.4%, 94.6%, and 49.2%, respectively. Network pharmacology indicated that quercetin and β-sitosterol could modulate lipid metabolism pathways. Moreover, the beverage showed potential for lipid-lowering. Its cholate adsorption capacity was 589.4 ± 2.9 mg/g at pH 7.0, and the IC₅₀ value for pancreatic lipase inhibition was 32.55 mg/mL. However, a 60-day storage stability test revealed that the moisture content approached 5%, likely due to polyphenol-flavonoid reactivity, extending dissolution time to 30.88 s. These changes were attributed to polyphenols (with flavonoids as the core active subclass, and non-flavonoids such as phenolic acids as auxiliary), resulting in color alterations and reduced solubility. This study confirmed the dual functions of the SL- RT beverage in antioxidant and lipid-lowering aspects. Nevertheless, it also pointed out the need to optimize the formula and process to enhance stability, providing an important basis for the development of stable functional beverages.

Keywords

Sophora japonica L. / Rosa rugosa Thunb. / polyphenols / flavonoids / antioxidant activity / lipid metabolism regulation / network pharmacology