PROCESS FOR EXTRACTION OF ANTIOXIDANTS FROM PLANT MATERIAL
The importance of natural sources of antioxidants has significantly increased in the last years. The reason is that artificial antioxidants are prohibited as food additives because of the potential toxic and carcinogen properties. The plants of the Labiatae family, for example Rosmarinus officinalis L., are rich in valuable antioxidants. The main antioxidants in rosemary are rosmarinic acid (hydrophilic) and carnosic acid (hydrophobic). The challenge is to extract carnosic acid by a selective, mild and environmentally friendly method, which avoids toxic or hazardous solvents.
Aqueous solutions of the soap sodium myristate, the salt of the saturated fatty acid myristic acid, were used for the extractions. It is a natural amphiphilic constituent partially occurring in nearly every plant. Also rosemary leaves contain a small amount of myristic acid. By the use of micellar extraction the total amount of rosmarinic acid and carnosic acid can be extracted within few minutes at room temperature or slightly increased temperature. Further processing steps result in the final extract.
Compared to conventional extraction methods of rosemary leaves, this is a significant saving in time and energy as no distillation or removal of the solvent is necessary. By means of the presented method fewer by-products are contained in the final extract compared to the conventional extract.
Thus, this new green extraction method allows a selective extraction of carnosic acid with a non-flammable, non-toxic, and green aqueous micellar solution. It is also the first process used to obtain carnosic acid by extractions of rosemary leaves with aqueous solutions.
The extract is highly desirable as
- food additive
- additive in animal feedstuff
- cosmetic preparations
Like conventional rosemary extracts, the micellar extract can be used as flavours, antioxidants and oil-soluble preservatives for lipid containing food like meat, poultry, fish, oil fat, sauce, and gravy. Also the antioxidant water residue, which is normally waste, can be an alternative to common antioxidants, like ascorbic acid, in conventional beverages. Furthermore, rosmarinic acid can be re-extracted from the water phase to gain the pure antioxidant.
Proof of Concept.
Ready to use.