PDF(Pubmed)
Abstract：
Rosmarinic acid (RA), an ester of caffeic acid and 3,4-dihydroxyphenyllactic acid, is a potent radical scavenger, a chelator of prooxidant ions, and an inhibitor of lipid peroxidation. RA-containing extracts are widely used natural antioxidants in food products, and many herbal preparations and food supplements, containing RA, are marketed with claims of beneficial health effects. The current study investigated the effectiveness of subcritical water extraction (SWE) for the recovery of RA from lemon balm (Melissa officinalis), as a \"green\" alternative to conventional hydro-alcoholic extraction. Different durations (10 min and 20 min) and extraction temperatures (100 °C and 150 °C) were applied. Subcritical water applied at a temperature of 100 °C was equally efficient as 50% ethanol in extracting RA. However, the further elevation of temperature to 150 °C decreased RA content by up to 20% due to thermal degradation. The content of RA in dried extracts was between 2.36% and 5.55% and the higher temperature of SWE increased extract yield by up to 41%. The higher extraction yield resulted from the degradation of plant material by subcritical water as evidenced by the increased extraction and degradation of proteins, pectin, and cellulose. These results reveal that SWE is an efficient technology for the extraction of RA and other antioxidants from lemon balm at reduced extraction time and without the use of toxic organic solvents. Furthermore, by modification of SWE conditions, dry extracts with different purity and content of RA are obtained. These extracts could be used in the food industry as food antioxidants, or in the development of food supplements and functional foods.
摘要：
迷迭香酸(RA),咖啡酸和3,4-二羟基苯基乳酸的酯，是一种有效的自由基清除剂，促氧化离子的螯合剂，和脂质过氧化抑制剂。含RA的提取物是食品中广泛使用的天然抗氧化剂，和许多草药制剂和食品补充剂，含有RA,在市场上声称有益健康。当前的研究调查了亚临界水提取（SWE）从柠檬香脂（Melissaofficinalis）中回收RA的有效性，作为传统水醇提取的“绿色”替代品。应用不同的持续时间(10分钟和20分钟)和提取温度(100°C和150°C)。在提取RA中,在100°C的温度下施加的亚临界水与50%乙醇同样有效。然而,由于热降解，温度进一步升高至150°C时，RA含量降低了20％。干燥提取物中RA的含量在2.36％至5.55％之间，SWE的较高温度使提取物产量增加了41％。亚临界水对植物材料的降解导致了较高的提取率，如蛋白质的提取和降解增加所证明的。果胶,和纤维素。这些结果表明，SWE是一种有效的技术，可以减少提取时间，不使用有毒有机溶剂，从柠檬香脂中提取RA和其他抗氧化剂。此外，通过修改SWE条件，获得具有不同纯度和RA含量的干提取物。这些提取物可以在食品工业中用作食品抗氧化剂，或在食品补充剂和功能性食品的开发中。
