关键词: 超微红茶粉体；冷藏；化学性质；胰脂肪酶活性；体质量；血脂

Abstract: In order to explore the cold storage properties and lipid-lowering efficacy of black tea superfine powder with different particle sizes, in this study, the physicochemical properties and lipid-lowering capacity of black tea superfine powders with particle sizes of 26.116 (about 600 mesh), 9.612 (about 1 600 mesh) and 4.338 μm (about 3 600 mesh) were evaluated after refrigerated storage at 4 ℃ for 180 days. The results showed that the contents of tea polyphenols (18.17%) and thearubigins (11.82%) were significantly (P < 0.05) higher in the 600-mesh tea powder than in the 1 600-mesh (17.36% and 10.76%, respectively) and 3 600-mesh (16.93% and 10.42%, respectively) ones after cold storage, while the content of theabrownines (3.96%) was significantly (P < 0.05) lower than that in the 1 600-mesh (4.67%) and 3 600-mesh (4.89%) tea powders. In addition, all the three tea powders significantly inhibited pancreatic lipase activity with half-maximum inhibitory concentration (IC50) values of 560.672–591.521 μg/mL and significantly improved body mass (392.5–396.3 g) and the serum levels of total cholesterol (1.756–2.052 mmol/L), triglycerides (3.611–4.308 mmol/L), low-density lipoprotein cholesterol (3.004–3.097 mmol/L) and high-density lipoprotein cholesterol (1.268–1.456 mmol/L) in obese rats after 35 days of gavage, with no significant differences being observed among these tea powders (P > 0.05). In summary, larger particle size of black tea superfine powder in the range of 600–3 600 mesh are beneficial to maintain its chemical components during cold storage, and have similar lipid-lowering effects in obese rats.

Key words: black tea superfine powders; cold storage; chemical properties; pancreatic lipase activity; body mass; blood lipids