Growing demand for natural food preservatives has stimulated increasing interest in polyphenolic compounds. However, their application in food systems is constrained by insufficient stability during processing and storage, which can lead to reduced antioxidant and antimicrobial efficacy and, consequently, compromised preservation performance. To address these limitations, green nanocarriers—including chitosan-based particles, liposomes, and nanoemulsions—have been widely explored to enhance polyphenol stability, enable controlled release, and improve compatibility within food matrices. This review systematically summarizes the bioactive properties of polyphenols, the design principles of green nanocarriers, and their applications in the preservation of meat, fruits and vegetables, and dairy products. Current evidence indicates that polysaccharide-, protein-, lipid-, and stimuli-responsive carrier systems can effectively enhance the antioxidant, antimicrobial, and anti-browning functions of polyphenols, extend food shelf life, and reduce health and environmental risks associated with synthetic preservatives. Taken together, the rational design and application of polyphenol-loaded green nanocarriers hold promise as an effective and sustainable strategy for food preservation.

Diaphragma juglandis (D. juglandis) Fructus is a brownish lamellar structure located between walnut kernels. As a traditional Chinese herbal medicine, it exhibits therapeutic effects including spleen-strengthening, kidney consolidation, astringency, diuresis, and heat-clearing. In this study, the polyphenolic constituents of D. juglandis and its functional instant tea were investigated in this study. Three polyphenolic compounds were isolated from 70% ethanol extract of D. juglandis Fructus as 2-methoxy juglone, regiolone and quercetin. The HPLC method was established for determination of the content of quercetin in the instant tea samples under the premise that the methodology was verified to meet the standard requirements. The preparation process of D. juglandis Fructus instant tea was optimized through single factor experiments and Box-Behnken design-response surface methodology and the optimal conditions were determined as follows: feed rate of 10 mL/min, inlet temperature of 151 ℃, and β-cyclodextrin addition of 9%. Then the antioxidant activity of each sample was evaluated using DPPH and ABTS radical scavenging assays. The results showed that the quercetin had significant antioxidant activity. The instant tea group demonstrated superior antioxidant effects compared to the extracts group at 50, 200, and 800 µg/mL (P < 0.001), likely due to the optimized spray-drying process, which might have enhanced the solubility, stability, and bioavailability of the active compounds. The results provided critical foundational data for the deep processing and comprehensive utilization of D. juglandis Fructus.

Genistein is a phytoestrogen with multiple biological activities. Studies have shown that genistein can exert anti- inflammatory activities through various pathways, and an in-depth study of its mechanism of action could develop more effective anti-inflammatory drugs. The poor solubility and stability of genistein limit its application. Researchers have developed a variety of novel delivery systems, such as nanocarriers, liposomes, and microemulsions, which can improve the solubility, stability, and in vivo distribution of genistein and enhance its therapeutic activity. The study presents the recent investigation on genistein’s effects on the anti-inflammatory mechanisms and delivery formulation of genistein.