Optimisation of microwave-assisted extraction parameters for antioxidants from waste Achillea millefolium dust

Polyphenols extraction from plant sources

“…Additionally, the highest content of polyphenols from A. melanocarpa was achieved by using 50% ethanol, whereas further increase of ethanol concentration led to the decrease of polyphenols yield (Simić et al, 2016). Milutinović et al (2015) have shown that in microwave-assisted extraction, the increase in solid/solvent ratio resulted in the enhancement of polyphenols content from A. millefolium, due to more efficient wetting of plant material. The increase in the diffusion coefficient and the intensive release of polyphenols from destroyed plant cells caused by microwaves, lead to the rapid saturation of the extraction medium.…”

“…Apart from that, the best efficiency of microwave-assisted extraction of polyphenols from Hippophae rhamnoides and A. melanocarpa was achieved with a degree of fragmentation less than 0.5 mm (Asofiei et al, 2016;Dandena et al, 2014). According to the recent publications, the increase of ethanol concentration in water medium caused the increase in the polyphenols yield from Achillea millefolium and Myrtus communis, which can be explained by polar distribution and dielectric constant Milutinović et al, 2015). The increase in dielectric constant, which is a result of the addition of water to ethanol, allows the absorption of microwaves energy.…”

“…The increase in dielectric constant, which is a result of the addition of water to ethanol, allows the absorption of microwaves energy. However, higher quantities of water lead to a reduced expanding of heat into extraction medium, which also reduces the efficiency of microwave extraction (Milutinović et al, 2015). Additionally, the highest content of polyphenols from A. melanocarpa was achieved by using 50% ethanol, whereas further increase of ethanol concentration led to the decrease of polyphenols yield (Simić et al, 2016).…”

“…The disadvantages of microwave-assisted extraction include (1) degradation of thermosensitive polyphenols constituents, (2) lower yield of non-polar and volatile target compounds, (3) the effects of microwaves on polyphenols yield depend on the polarity of solvents, and (4) a possibility of the extraction of a large quantity of ballast substances. Microwave-assisted extraction is widely and successfully applied technique for obtaining polyphenols extracts from different plant matrixes, such as chokeberry fruit and yarrow, myrtle and sea buckthorn leaves (Asofiei et al, 2016;Milutinović et al, 2015;Simić et al, 2016;Dandena et al, 2014). From the point of view of environmental protection and food, pharmaceutical and cosmetic industries, which require safe and high quality products, with the application of "green" extraction methods, which are quick and automated, microwave-assisted extraction is a recommended method for obtaining high quality extracts from numerous plant sources, with high polyphenols yield (Bouras et al, 2015).…”

Chemical composition of the essential oils and extracts of Achillea species and their biological activities: A review

“…For this purpose, wellknown antioxidant assays including 1,1-diphenyl-1-picrylhydrazil or 2,2-diphenyl-1-picrylhydrazil (DPPH), Fe 3+ -EDTA-H2O2 deoxyribose (hydroxyl radical scavenging activity: FEHD or HRSA), inhibition of lipid peroxidation assay (ILPA), inhibition of superoxide radicals assay (ISRA), inhibition of hydroxyl radicals (IHRA), phosphomolybdenum (PM), ferric thiocyanate (FTC), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), β-carotene-linoleic acid bleaching assay (BCLBA), chemiluminescence assay (CLA) were utilized. In some of these studies, satisfactory IC50 values were reported which were even less than those of some synthetic or natural antioxidants (Candan et al, 2003;Sokmen et al, 2004;Jianu et al, 2015;Kazemi, 2015c, b;Milutinovic et al, 2015;Turkmenoglu et al, 2015;Venditti et al, 2015).…”