OPTIMIZATION OF POLYPHENOL EXTRACTION FROM VINE SHOOTS AND GRAPE POMACE HIBA N. RAJHAA,B, NADIA BOUSSETTAB, ZEINA HOBAIKAA, NICOLAS LOUKAA, EUGENE VOROBIEVB, RICHARD G. MAROUNA A Centre
d’Analyses et de Recherche, UR TVA, Faculté des Sciences, Université Saint-Joseph, B.P. 11-514 Riad El Solh, Beirut 1107 2050, Lebanon.
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Sorbonne universités, Université de technologie de Compiègne, laboratoire Transformations Intégrées de la Matière renouvelable (UTC/ESCOM, EA 4297 TIMR), Centre de recherche Royallieu, CS 60 319, 60 203 Compiègne cedex, France.
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B
The extraction of polyphenols from vine shoots was conducted with conventional solid liquid (CSL) processes and innovative technologies such as high-voltage electrical discharges (HVED), pulsed electric fields (PEF) and ultrasounds (US)[1]. Several solvents and extraction techniques were tested and their conditions optimized by response surface methodology. The efficiency of water was the lowest followed by β-Cyclodextrin (37.7 mg/mL), ethanol/water (50%) and sodium hydroxide (1 M) extractions. The application of US, PEF and HVED as pretreatments enhanced notably the extraction process. The highest polyphenol yield was obtained with HVED pretreatment, with an amelioration of 2.7 times compared to untreated samples. Similarly, the extraction of polyphenols from grape pomace was done with CSL and with a non-conventional method, the accelerated solvent extraction (ASE)[2]. The optimization of particle size, time, temperature and solvent mixture was realized. High polyphenol yields were obtained at high-temperature and low-duration extractions in hydroethanolic solvents[3]. ASE enhanced 3 times the polyphenol extraction process from grape pomace at 140 ºC. In conclusion, we clearly showed that vine shoots and grape pomace are rich sources of bioactive molecules. The extraction of these molecules is greatly enhanced by US, PEF, HVED and ASE and thus could be used for several industrial applications. [1] Rajha, H. N., Boussetta, N., Louka, N., Maroun, R. G., & Vorobiev, E. (2014). A comparative study of physical pretreatments for the extraction of polyphenols and proteins from vine shoots. Food Research International, 65, 462468. [2] Rajha, H. N., Ziegler, W., Louka, N., Hobaika, Z., Vorobiev, E., Boechzelt, H. G., & Maroun, R. G. (2014). Effect of the Drying Process on the Intensification of Phenolic Compounds Recovery from Grape Pomace Using Accelerated Solvent Extraction. International journal of molecular sciences, 15(10), 18640-18658. [3] Rajha, H. N., El Darra, N., Hobaika, Z., Boussetta, N., Vorobiev, E., Maroun, R. G., & Louka, N. (2014). Extraction of total phenolic compounds, flavonoids, anthocyanins and tannins from grape byproducts by response surface methodology. Influence of solid-liquid ratio, particle size, time, temperature and solvent mixtures on the optimization process. Food and Nutrition Sciences, 5, 397-409.
