Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia.
Nutrition and Food Science Area, Preventive Medicine and Public Health, Food Sciences, Toxicology and Forensic Medicine Department, Faculty of Pharmacy, Universitat de València, Avda. Vicent Andrés Estellés, s/n, 46100 Burjassot, València, Spain.
Food Chem. 2018 Jul 15;254:150-157. doi: 10.1016/j.foodchem.2018.01.192. Epub 2018 Feb 2.
Stevia rebaudiana Bertoni leaves are a natural source of diterpenic glycosides, and various bioactive compounds. The objectives were to characterize antioxidants and steviol glycosides in the extracts obtained from Stevia after "green" pressurized hot water extraction (PHWE). PHWE extracts were obtained at different temperatures (100, 130, 160 °C); static extraction times (5 and 10 min), and cycle numbers (1, 2, 3) using a constant pressure of 10.34 MPa. Temperature was the most important parameter for extraction, where the highest recoveries of all bioactive compounds (except for carotenoids) were at 160 °C. Extracts obtained at longer static times had more steviol glycosides, condensed tannins, and chlorophyll A. Higher amounts of total phenols, condensed tannins, and steviol glycosides were obtained under higher cycle numbers. This study indicated that PHWE is useful for recovering polar and nonpolar antioxidants and steviol glycosides. PHWE may be a suitable technique for scale-up to industrial applications.
甜菊叶是二萜类糖苷和各种生物活性化合物的天然来源。本研究的目的是对甜菊经“绿色”加压热水提取（PHWE）后提取物中的抗氧化剂和甜菊糖苷进行表征。在恒压 10.34 MPa 下，分别使用 100、130 和 160°C 的不同温度、5 和 10 min 的静态提取时间以及 1、2 和 3 个循环数，提取 PHWE 提取物。温度是提取的最重要参数，所有生物活性化合物（类胡萝卜素除外）的最高回收率均在 160°C 时达到。在较长的静态时间下获得的提取物含有更多的甜菊糖苷、缩合单宁和叶绿素 A。在较高的循环数下，可获得更多的总酚类、缩合单宁和甜菊糖苷。本研究表明，PHWE 可用于回收极性和非极性抗氧化剂和甜菊糖苷。PHWE 可能是适合工业应用放大的技术。
