Year 2018, Volume 3, Issue 3

Year : 2018
Volume : 3
Issue : 3
Authors : Simona OANCEA, Maria RADU
Abstract : Onion represents one of the most important crop, based on its production, consumption and high pharmacological potential supported by its chemical composition. Phytochemicals of phenolic structure, in particular anthocyanins, are among the strongest antioxidant compounds with large biological and industrial applications. Because their conventional extraction involves the use of high amounts of polar organic solvents, there is a strong requirement for development of new strategies based on greener solvents. The aim of the present paper was to extract valuable compounds of polyphenolic structure from red onion wastes using deep eutectic solvents, as green strategy for their isolation. In addition, the total antioxidant activity as measured by ferric reducing antioxidant capacity assay was investigated. Extraction performed at 40oC in the selected solvent system was optimized for two parameters, solvent/sample ratio and extraction time. The obtained results showed the highest content of anthocyanins and antioxidant activity at a solvent/sample ratio of 30/1 and the extraction time of 90 min, at 40oC. Regarding the total phenolics and flavonoids, the optimal extraction parameters were 20/1 solvent/sample ratio and 90 min, at 40oC. Compared to conventional extraction in organic solvent, the values of the antioxidant activity were similar, while those of the content of bioactive compounds were higher in extracts obtained in ethanol solution. By further optimization of the extraction process, the obtained products may find useful application in obtaining natural ingredients intended for different purposes.
For citation : Oancea, S., Radu, M. (2018). Phenolic composition and antioxidant activity of green-solvents-based extracts of red onion wastes. AGROFOR International Journal, Volume 3. Issue No. 3. pp. 106-113. DOI: 10.7251/AGRENG1803106O
Keywords : Red onion wastes, deep eutectic solvents, phenolics, anthocyanins, antioxidant activity
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