Selenium (Se)-enriched tea has gained growing global popularity due to its superior health benefits compared to normal tea. The sensory quality and health attributes of tea soup are determined by the dissolution patterns of selenium-enriched teas. This study compared the chemical profiles of selenium-enriched black tea (SeBT), selenium-enriched green tea (SeGT), normal black tea (BT), and normal green tea (GT). The dissolution patterns and sensory evaluation of SeGT and SeBT were investigated under different brewing conditions. Through establishing a daily tea drinking model, the antioxidant activity, hypoglycemic activity, and antibacterial activity of tea soup before and after simulated digestion were determined. In comparison, SeGT exhibited rapid dissolution of chemical components but was prone to bitterness in the tea infusion, which was best brewed at 100 °C for 5-7 min to optimize functional component release while avoiding bitterness, demonstrating stronger antioxidant, hypoglycemic and antibacterial potential. Meanwhile, SeBT showed a slower release rate of chemical components but greater stability across brewing conditions, which was well-suited for brewing at 85 °C or 100 °C for 3-7 min, with its inherent sweetness and mild flavor appealing to a broader consumer base. This study evaluated the quality of different selenium-enriched teas, explored the dissolution patterns, sensory evaluation, and in vitro bioactivities of tea soup, providing guidance for consumers in selecting optimal brewing conditions for different selenium-enriched teas that combine flavor and nutritional characteristics.

Casein and α-lactalbumin (α-LA) are the main allergens in cow's milk, which can affect the skin, respiratory system, and gastrointestinal tract, even cause anaphylactic shock. Developing a rapid and sensitive detection method of casein and α-LA is still pursued. Herein, a surface-enhanced Raman scattering based lateral flow assay (SERS-LFA) method for rapid and highly sensitive detection of milk allergens in food was established for effectively preventing allergic symptoms. Gold@silver nanoparticles (Au@Ag NPs) were synthesized as SERS active substrate to prepare the antibody-modified SERS Probe and SERS-LFA strips toward casein and α-LA were assembled according to the sandwich mode. The detection results were calculated according to colorimetric and Raman signal. The introduction of SRES signal significantly increased the sensitivity of detection with the limit of detection (LOD) of 0.19 ng/mL and 1.74 pg/mL, and exhibited an excellent linear relationship within the range of 0.55-791.50 ng/mL and 0.1 pg/mL-100.0 ng/mL for casein and α-LA, respectively. Furthermore, SERS-LFA strips was highly specific with the recovery rates for corresponding 80.36%-105.12% and 85.73%-118.22% for casein and α-LA, respectively. Therefore, the SERS-LFA could be in great potential to develop a unique allergen detection method.

High-salt diet is well recognized as a risk factor for hypertension, and dietary intervention plays a critical role in the prevention of hypertension. The current study investigated the effects of selenium-enriched green tea (Se-GT) and ordinary green tea (GT) on prevention of hypertension of rats induced by high-salt diet, as well as their potential regulatory and mechanism. Our results showed that GT and Se-GT supplementations significantly prevented the increase of blood pressure (BP), activated the phosphoinosmde-3-kinase/protein kinase B (PI3K/Akt) signaling pathway, and regulated the gene expression related to BP, as well as improved the tissue damage like heart, liver, and kidneys. Besides, the key parameters associated with oxidative stress, inflammation and endothelial dysfunction were also altered by GT and Se-GT treatments. Importantly, GT or Se-GT administration adjusted the diversity and composition of the intestinal flora. Moreover, GT and Se-GT supplementations increased the abundance of beneficial bacteria and reduced the abundance of harmful or conditional pathogenic bacteria. More specifically, GT intake specifically and significantly enriched the relative abundance of Paraprevotella and Bacteroides, whereas Se-GT was characterized by specific and significant enrichment for Allobaculum and Bifidobacterium. Our results proved that dietary supplement of GT and Se-GT remarkably improved the vascular functions and effectively prevented tissue damage by regulation of intestinal flora, and thus preventing hypertension induced by high-salt diet.