Study on the application of quercetin and β-carotene embedded by broken rice porous starch

Broken rice is a major by-product of the rice processing industry, while β-carotene and quercetin are bioactive compounds with health benefits but suffer from poor bioavailability, low water solubility and instability. In this study, quercetin and β-carotene were encapsulated by broken rice porous starch to form microcapsules, and their physicochemical properties, structural characteristics, stability and release profiles were analyzed using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and laser particle size analysis. The results demonstrated that encapsulation significantly enhanced photostability, increasing retention by 41 % for quercetin and 44 % for β-carotene compared to their free forms. Thermal stability at 100 °C also improved, with quercetin and β-carotene stability increasing by 44 % and 65 %, respectively. Furthermore, the encapsulated compounds exhibited sustained release properties: encapsulated quercetin showed less than 15 % gastric release (compared to 25-35 % for free quercetin) and 75 % intestinal release after 6 h (compared to 85 % for free quercetin), while encapsulated β-carotene achieved 40-50 % intestinal release (compared to 25 % for free β-carotene). The above results show that encapsulation with quercetin and β-carotene microcapsules prepared by broken rice porous starch can stabilize the functional components of food and can be used as a promising encapsulated wall material.