Santos Jânio Sousa, Deolindo Carolina Turnes Pasini, Esmerino Luis Antônio, Genovese Maria Inés, Fujita Alice, Marques Mariza Boscacci, Rosso Neiva Deliberali, Daguer Heitor, Valese Andressa Camargo, Granato Daniel
Food Science and Technology Graduate Program, State University of Ponta Grossa, Av. Carlos Cavalcanti, 4748, 84030-900, Ponta Grossa, Brazil.
Department of Clinical Analysis, State University of Ponta Grossa, Av. Carlos Cavalcanti, 4748, 84030-900, Ponta Grossa, Brazil.
Food Res Int. 2016 Nov;89(Pt 1):476-487. doi: 10.1016/j.foodres.2016.08.041. Epub 2016 Aug 28.
This work was aimed at assessing the time-temperature effects on the phenolic compounds and in vitro functional properties of aqueous extracts from red rooibos (Aspalathus linearis). The major phenolic composition (tannins, flavonoids, flavonols, ortho-diphenols, total phenolic content), antioxidant (ABTS and DPPH) and reducing capacities (FRAP and total reducing capacity), antimicrobial effects and inhibition of α-amylase/α-glucosidase were measured. Phenolic compounds were also determined by LC-ESI-MS/MS. Aqueous extracts did not inhibit the growth of Escherichia coli, Staphylococcus aureus, and Candida albicans between 7.81 and 1000mgL. Rooibos extracted at 85°C for 10min showed a beneficial interaction with the human erythrocytes, reducing the hemolysis. The correlation analysis showed that the phenolic compounds responsible for the inhibition of α-amylase (IC) were isohrmanetin, isoquercitrin, luteolin, salicylic acid, and syringaldehyde, whereas the inhibition of α-glucosidase was correlated to syringaldehyde, isoquercitrin, and luteolin. Overall, rooibos extracted at 85°C had the highest antioxidant activity measured by all assays, higher contents of phenolic compounds (spectrophotometric and LC-ESI-MS/MS data), and lower IC values for the digestive enzymes. On the other hand, rooibos extracted at 65°C had the opposite behavior, while rooibos extracted at 75°C presented mean intermediate values for the responses. This result clearly indicates that the extraction temperature is the main factor leading to a higher extraction of bioactive compounds from red rooibos.
本研究旨在评估时间-温度对红灌木（Aspalathus linearis）水提取物中酚类化合物及体外功能特性的影响。测定了主要酚类成分（单宁、黄酮类化合物、黄酮醇、邻二酚、总酚含量）、抗氧化能力（ABTS和DPPH）、还原能力（FRAP和总还原能力）、抗菌效果以及对α-淀粉酶/α-葡萄糖苷酶的抑制作用。酚类化合物也通过LC-ESI-MS/MS进行测定。水提取物在7.81至1000mg/L之间未抑制大肠杆菌、金黄色葡萄球菌和白色念珠菌的生长。85°C提取10分钟的红灌木提取物与人红细胞呈现出有益的相互作用，减少了溶血现象。相关性分析表明，负责抑制α-淀粉酶（IC）的酚类化合物是异荭草素、异槲皮苷、木犀草素、水杨酸和丁香醛，而对α-葡萄糖苷酶的抑制作用与丁香醛、异槲皮苷和木犀草素相关。总体而言，85°C提取的红灌木提取物在所有测定中具有最高的抗氧化活性、较高的酚类化合物含量（分光光度法和LC-ESI-MS/MS数据）以及较低的消化酶IC值。另一方面，65°C提取的红灌木提取物表现出相反的行为，而75°C提取的红灌木提取物在各项响应中呈现出平均中间值。这一结果清楚地表明，提取温度是导致从红灌木中更高提取生物活性化合物的主要因素。
