The consumption of plant-based food is important for health promotion, especially concerning the prevention and management of chronic diseases. Flavonoids are the main bioactive compounds in citrus fruits, with multiple beneficial effects, especially antidiabetic effects. We systematically review the potential antidiabetic action and molecular mechanisms of citrus flavonoids based on in vitro and in vivo studies. A search of the PubMed, EMBASE, Scopus, and Web of Science Core Collection databases for articles published since 2010 was carried out using the keywords citrus, flavonoid, and diabetes. All articles identified were analyzed, and data were extracted using a standardized form. The search identified 38 articles, which reported that 19 citrus flavonoids, including 8-prenylnaringenin, cosmosiin, didymin, diosmin, hesperetin, hesperidin, isosiennsetin, naringenin, naringin, neohesperidin, nobiletin, poncirin, quercetin, rhoifolin, rutin, sineesytin, sudachitin, tangeretin, and xanthohumol, have antidiabetic potential. These flavonoids regulated biomarkers of glycemic control, lipid profiles, renal function, hepatic enzymes, and antioxidant enzymes, and modulated signaling pathways related to glucose uptake and insulin sensitivity that are involved in the pathogenesis of diabetes and its related complications. Citrus flavonoids, therefore, are promising antidiabetic candidates, while their antidiabetic effects remain to be verified in forthcoming human studies.

In this study, the feasibility of improving the extraction yield of green tea antioxidant polyphenols by the combination of ultrasound-assisted extraction (UAE) and deep eutectic solvents (DESs) was investigated. Choline chloride (ChCl)-glycerol was selected as the best DES among 12 ChCl-based DESs to extract tea antioxidant polyphenols. Subsequently, the influences of extraction parameters on total phenolic content (TPC) values were investigated, and liquid/solid ratio, ultrasonic power, and ultrasonic time were optimized based on the response surface methodology. The optimal extraction conditions were a liquid to solid ratio of 36:1 (mL/g), ultrasonic power of 461.5 W, and ultrasonic time of 21 min, with the highest TPC value of 243 ± 7 mg gallic acid equivalent (mg GAE)/g dry weight (DW), which was 13% higher than that before optimization. In addition, under the optimal extraction conditions, tea polyphenolic extract exhibited higher antioxidant activity compared with conventional extraction methods. Four major catechins in the green tea extracts, including (−)-epicatechin (EC), (−)-epigallocatechin (EGC), (−)-epicatechin gallate (ECG) and (−)-epigallocatechin gallate (EGCG) were identified and quantified by high-performance liquid chromatography. In addition, scanning electron microscopy (SEM) analysis revealed that UAE-DES effectively disrupted the green tea leaf cells, thereby improving tea polyphenol yield. In summary, UAE-DES is an ideal green extraction method for the extraction of tea antioxidant polyphenols.

The effects of high-intensity ultrasonic (HIU) treatment on the functional properties of egg yolk were studied in the present work. After HIU treatment, the emulsifying, foaming and gel properties of the egg yolk solution significantly increased, but the foam stability decreased. SDS-PAGE results showed that there was no obvious change in the protein bands of egg yolk, indicating that the yolk proteins did not undergo covalent crosslinking or degradation. HIU treatment enhanced the zeta potential of egg yolk components in solution and increased the free sulfhydryl content of egg yolk proteins. Moreover, the particle size distribution of egg yolk components in solution changed markedly, and these changes demonstrated that HIU treatment caused the aggregation of yolk low-density lipoprotein and the partial dissociation of yolk granules. These results revealed that HIU treatment could change the aggregation of yolk components, which in turn could influence the solution characteristics of egg yolk, finally resulting in changes to the functional properties of egg yolk.