Extraction of Polyphenols from Vine Shoots of Vitis vinifera by Superheated Ethanol-Water Mixtures
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- 作者：José ; M. Luque-Rodrí ; guez ; Pedro Pé ; rez-Juan ; Marí ; a D. Luque de Castro
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2006
- 出版时间：November 15, 2006
- 年：2006
- 卷：54
- 期：23
- 页码：8775 - 8781
- 全文大小：414K
- 年卷期：v.54,no.23(November 15, 2006)
- ISSN：1520-5118
文摘
A study of the nonvolatile fraction of extracts from vine shoots obtained by superheated ethanol-water mixtures is presented. The influence of the temperature, extraction time, and percentage ofethanol on extraction was investigated by a multivariate experimental design to maximize the yieldof total phenolic compounds, measured by using the Folin-Ciocalteu method. The best values foundfor these variables were 80% (v/v) ethanol, 240 
C, and 60 min. Under these conditions, the effectof pH was also investigated, and a strong improvement of yield was observed by decreasing the pH.The extracts were subject to liquid-liquid extraction with n-hexane. The remaining polar phase wasdried in a rotary evaporator and then reconstituted in 10 mL of water. The insoluble residue wasdissolved in 10 mL of methanol. Both fractions (aqueous and methanolic) were analyzed by HPLC,and the differences in composition according to the extraction conditions were studied. Compoundsusually present in commercial wood extracts were identified (mainly benzoic and hydroxycinnamicacids and aldehydes); the most abundant were quantified, and the stability of the identified phenolicfamilies under different extraction conditions was also investigated. Finally, the superiority of thesuperheated liquid extraction over conventional solid-liquid extraction was demonstrated.
C, and 60 min. Under these conditions, the effectof pH was also investigated, and a strong improvement of yield was observed by decreasing the pH.The extracts were subject to liquid-liquid extraction with n-hexane. The remaining polar phase wasdried in a rotary evaporator and then reconstituted in 10 mL of water. The insoluble residue wasdissolved in 10 mL of methanol. Both fractions (aqueous and methanolic) were analyzed by HPLC,and the differences in composition according to the extraction conditions were studied. Compoundsusually present in commercial wood extracts were identified (mainly benzoic and hydroxycinnamicacids and aldehydes); the most abundant were quantified, and the stability of the identified phenolicfamilies under different extraction conditions was also investigated. Finally, the superiority of thesuperheated liquid extraction over conventional solid-liquid extraction was demonstrated.