An abundant and low-cost agricultural waste such as
vine shoots (
Vitis vinifera) (VS), which isgenerated by the annual pruning of
vineyards, has been used as raw material in the preparation ofpowder activated carbon (AC) with a view to develop a new fining agent for white wines. A commercialactivated carbon, S5X-Agro
vin, was used for comparison purposes. From VS size-reduced pieces,AC was prepared using phosphoric acid as activating agent. The concentration of the H
3PO
4 solution,the impregnation temperature, and the carbonization conditions were controlled. The carbons weretexturally characterized by gas adsorption (N
2, -196
C), mercury porosimetry, and densitymeasurements. FT-IR spectroscopy was used in the analysis of the surface functional groups andstructures of the carbons. Three varieties of white wine (i.e., cv. Cayetana, cv. Macabeo, and cv.Sauvignon Blanc) were treated with the activated carbons. Color changes were monitored by UV-vis spectrometry. Significant differences in the degree of uptake of polyphenols were observeddepending on the wine variety and on the method of preparation of activated carbon. The carbonprepared by first impregnation of VS with the 60 vol% H
3PO
4 solution at 50
C and by thencarbonization of the resultant product at 400
C for 2 h presents a higher ability to discolor the whitewines. The action of this carbon is comparable to that shown by the commercial product. Both carbonspossess a well-developed porosity in the macropore range.Keywords: Vine shoots; chemical activation; activated carbon; white wines