Departamento de Productos Forestales, Centro de Investigación Forestal (CIFOR), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Apdo. 8111, 28080 Madrid, Spain.
Anal Chim Acta. 2010 Feb 15;660(1-2):211-20. doi: 10.1016/j.aca.2009.09.031. Epub 2009 Sep 26.
The increasing demand for wood for barrel-making in addition to the rapid extension of alternative aging system, have led to looking into the possibility of utilizing Spanish oak. Quercus pyrenaica is the species that predominates in Spain, and the chemical composition of its heartwood (ellagitannins, low molecular weight phenolic and volatile compounds) and its incidence in characteristics of wine are similar to that of other species that are of recognized oenological quality for barrel-making, showing only quantitative differences with respect to French (Quercus petraea) and American (Quercus alba) species. However, at present, the quantity of good quality wood that we can obtain from the Q. pyrenaica Spanish forest is limited. Hence, in the short term, and considering the high chemical oenological quality of Q. pyrenaica wood, we propose the utilizing of chips, segments, staves, and other oak alternatives for wine aging, which would be obtained from wooden remnants from barrel-making as well as from trees with small diameters or physical defects which would normally be inappropriate for cooperage. With regards to the latter idea, studies on special chip-making processes, and other oak wood pieces are being carried out, especially focused on reducing seasoning time, and to toasting optimization as a function of wood piece size, in addition to its behaviour when incorporated into the different alternative aging systems. We present in this study the effect of seasoning way (traditional or unconventional) on volatile composition of Q. pyrenaica chips and staves at three toasting levels (light, medium and heavy), and the evolution of the wood-released aromatic composition of a Spanish artificially aged wine, using these alternative products. The wines showed in general small differences in their oak-derived characteristics, which were more related to the wood piece size and the toasting intensity than to the seasoning way, and they could be linked with the concentrations of compounds as eugenol, furfural, and the cis and trans isomers of beta-methyl-gamma-octolactone.
除了快速扩展的替代陈酿系统之外，对制桶用木材需求的增加也促使人们研究利用西班牙栎木的可能性。栓皮栎是西班牙的主要树种，其心材的化学成分（鞣花单宁、低分子量酚类和挥发性化合物）及其在葡萄酒中的特征与其他被认为具有制桶优质的酿酒橡木品种相似，只是在数量上与法国（栓皮栎）和美国（白栎）品种有所不同。然而，目前我们可以从西班牙栓皮栎森林中获得的优质木材数量有限。因此，短期内，考虑到栓皮栎木材的高化学酿酒质量，我们建议利用来自制桶剩余物的木屑、木片、桶板和其他橡木替代品进行葡萄酒陈酿，以及来自直径较小或存在物理缺陷的树木，这些树木通常不适合制桶。关于后一种想法，正在进行特殊制木片工艺和其他橡木木片的研究，特别是侧重于减少陈化时间，并根据木片尺寸优化烘烤，此外还研究了其在不同替代陈酿系统中的行为。本研究探讨了传统或非常规陈化方式对三种烘烤程度（轻度、中度和重度）下栓皮栎木片和桶板的挥发性成分的影响，以及这些替代产品对西班牙人工陈酿葡萄酒中释放的木质芳香成分的演变。总体而言，这些葡萄酒在橡木衍生特征方面的差异较小，这些差异更多地与木片尺寸和烘烤强度有关，而与陈化方式关系不大，并且可以与化合物的浓度相关联，如丁香酚、糠醛以及β-甲基-γ-辛内酯的顺式和反式异构体。
