Submitted to: Food Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/1/2007
Publication Date: 8/7/2007
Citation: Luthria, D.L. 2007. Influence of experimental conditions on the extraction of phenolic compounds from parsley (Petroselinum crispum) flakes using a pressurized liquid extractor. Food Chemistry. doi:10.1016/j.foodchem.2007.08.074 Interpretive Summary: Phenolic phytochemicals have been tested in the prevention of a wide range of health problems. This article describes parameters that influence extraction of phenolic phytochemicals from parsley flakes using a pressurized liquid extractor. The extraction yield of the phenolic compounds was influenced by temperature, particle size, and solid-to-solvent ratios. Temperature had a major impact on the phenolic profile, as at higher extraction temperatures, malonyl-apiin was partially degraded to acetyl-apiin and apiin. No significant impact of the amount of phenolic compounds extracted from parsley flakes was observed with the other two parameters (static time and pressure). Improved estimation of the phenolic content of parsley flakes will enable researchers to accurately evaluate the role of phenolic compounds in health and develop better dietary and safety guidelines on consumption of phenolic phytochemicals.
Technical Abstract: The influence of six pressurized liquid extraction parameters (temperature, pressure, particle size, flush volume, static time, and solid to-solvent ratio) on extraction of phenolic compounds from parsley flakes was examined. Parsley extracts were analyzed for their phenolic content by high performance liquid chromatography and Folin-Ciocalteu assay procedures. The two major phenolic compounds extracted from parsley flakes were identified as apiin and malonyl-apiin. Particle size, solid-to-solvent ratio, and temperature influenced the amount of phenolic compounds extracted from parsley flakes. Optimum extraction of phenolics was obtained when extractions were performed with the smallest particle size (<0.425 mm) fraction. The impact of particle size on extraction efficiency of phenolic compounds was reduced when extractions were carried out at higher temperatures. Temperature also showed a significant impact on the phenolic profile of the parsley extracts. The yield of malonyl-apiin decreased, while the amount of acetyl-apiin improved with the increase in extraction temperature. The latter compound (acetyl-apiin) is formed by decarboxylation of malonyl-apiin. Flush volume did not show any major influence on phenolic yields, but it can be manipulated to reduce usage of extraction solvents, which in turn decreases solvent waste disposable costs generated after extraction. Similarly changes in the static time (extraction time per cycle) and pressure did not result in any significant change in the yield of phenolic compounds extracted from parsley samples. However, sample throughput can be increased by reducing static time.