Submitted to: Journal of the Science of Food and Agriculture
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/24/2005
Publication Date: 5/22/2006
Citation: Luthria, D.L., Mukhopadhyay, S., Kwansa, A. 2006. A systematic approach for extraction of phenolic compounds using parsley (petroselinum crispum) flakes as a model substrate. Journal of the Science of Food and Agriculture. 86:1350-1358 Interpretive Summary: This paper depicts the importance of sample preparation on analysis of phenolic compounds from food samples. Influence of extraction solvents, number of extraction cycles and sample extraction procedures on isolation of phenolic compounds from a food substrate has been presented. This is critical for accurate determination of total phenolic compounds present in various food matrices. This will enable researchers to accurately evaluate the role of phenolics phytonutrients in diet and health and establish appropriate dietary intakes and guidelines.
Technical Abstract: The impact of sample preparation on the extraction of phenolic compounds from a phenolic enriched substrate, parsley (Petroselinum crispum) flakes, was investigated. Five different extraction procedures (shaking, vortexing, sonication, stirring and pressurized liquid extraction or PLE), and three different solvents (methanol, ethanol, and acetone), with five different proportions of solvent to water ratios per solvent were used for extraction. Extracts were analyzed for phenolic content by HPLC analysis and Folin-Ciocalteu assay. The yields of phenolic compound extracted with PLE were better than or comparable to the other four classical extraction procedures. Optimum extraction efficiency with PLE was obtained when extractions were performed with four extraction cycles using ethanol:water (50:50, % v/v). The amount of apiin (4,5,7-trihydroxyflavone-7-apiosylglucoside) and malonyl-apiin (apigenin-malonyl-apiosylglucoside) isolated from parsley varied with the composition of extraction solvent. Apiin extractability was found to be maximum with a ratio of 30% solvent (ethanol, methanol or acetone) to 70% water, whereas, higher amounts of malonyl-apiin were isolated with 70% solvent. Malonyl-apiin was not detected when parsley samples were extracted with 10% and 30% solvent.