Six Common Herbs with Distinctive Bioactive, Antioxidant Components. A Review of Their Separation Techniques

Abstract

Rosemary, oregano, pink savory, lemon balm, St. John’s wort, and saffron are common herbs wildly grown and easily cultivated in many countries. All of them are rich in antioxidant compounds that exhibit several biological and health activities. They are commercialized as spices, traditional medicines, or raw materials for the production of essential oils. The whole herbs or the residues of their current use are potential sources for the recovery of natural antioxidant extracts. Finding effective and feasible extraction and purification methods is a major challenge for the industrial production of natural antioxidant extracts. In this respect, the present paper is an extensive literature review of the solvents and extraction methods that have been tested on these herbs. Green solvents and novel extraction methods that can be easily scaled up for industrial application are critically discussed.

Formulation of Rosemary Extracts through Spray-Drying Encapsulation or Emulsification

“…Among them, antioxidants from rosemary are broadly recognized and have received the EU approval for use in food (E-392, European Union directives 2010/67/EU and 2010/69/EU), and their market is expected to raise up to 260 million US$ by 2024 [5]. Rosemary is one of the few plants (including common Salvia species) that contains carnosic acid and carnosol as their main antioxidant components [6]. In addition, the plant is rich in rosmarinic acid, which is a potent radical scavenger and antioxidant [7,8].…”

“…In addition, the plant is rich in rosmarinic acid, which is a potent radical scavenger and antioxidant [7,8]. Rosmarinic acid is present in some herbs of the Lamiaceae family and is responsible for the high antiradical and antioxidant activities of the extracts obtained from these herbs [6]. Other phenolic components of the plant comprise flavonoids, mainly in the form of glycosides [6].…”

“…Most research efforts examined the extraction of antioxidants by using organic solvents, such as acetone, ethanol, and methanol, or their mixtures with water [6][7][8]. Researchers focused mainly on the quantitative recovery of rosmarinic acid, carnosic acid, and carnosol, as they are the main antioxidant components of rosemary [7][8][9][10].…”

“…Researchers focused mainly on the quantitative recovery of rosmarinic acid, carnosic acid, and carnosol, as they are the main antioxidant components of rosemary [7][8][9][10]. Conventional, solid/liquid extraction is a broadly used method, while novel procedures, in particular, ultrasoundassisted extraction (UAE), microwave assisted extraction (MAE), and accelerated solvent extraction (ASE), have been examined [6,[8][9][10][11][12][13].…”

LC-MS Identification and Quantification of Phenolic Compounds in Solid Residues from the Essential Oil Industry

“…The literature reports different extraction procedures for phenolics utilizing conventional liquid extraction involving organic solvents, such as methanol, ethanol, acetone, ethyl acetate, butanone, hexane as well as mixtures of them with or without water [ 11 ]. Conventional extraction of phenolics may be also coupled with Soxhlet extraction or without it [ 12 , 13 , 14 ] as well as with the application of new technologies such as microwave [ 15 , 16 , 17 ] or ultrasound [ 1 , 16 , 17 ], in order to reduce the time and energy required to obtain phenolic extracts.…”