Phenolic compounds are released from the wood into the wine spirit (WS) during the ageing process, and are of utmost importance to the colour, flavour, taste and the overall quality acquired by this spirit drink.1 Their concentrations in the WS and the related effects mainly depend on the kind of wood (oaks vs chestnut), toasting level and ageing technology (traditional using wooden barrels vs alternative).1,2,3
Recent research conducted by our team has been focused on alternative technology towards sustainable ageing of WS resorting to wooden staves combined with micro-oxygenation (MOX).2,3 In the Project CENTRO-04-3928-FEDER-000001, the same wine distillate was aged for 18 months in 1000 L stainless steel tanks with wood staves inside (Limousin oak or chestnut) and MOX (flow rate 2 mL/L/month), and in 250 L barrels made of the same kinds of wood, in duplicate. Despite the promising results achieved, showing faster ageing and the production of high quality aged WSs resulting from the alternative technology compared to those resulting from the traditional one, it is imperative to assess their quality during the storage in bottle to fully validate the new technology. Therefore, the second phase of the investigation is currently made under the Project CENTRO-04-3928-FEDER-000028, studying the chemistry underlying the storage in bottle in order to understand if the features imparted by the ageing technology are retained or if they do not persist. The present work is focused on the behaviour of phenolic compounds of the aged WSs during this stage. For this purpose, the eight aged WSs (from the four modalities: chestnut barrels, Limousin oak barrels, stainless steel tanks with chestnut wood staves and MOX, and stainless steel tanks with Limousin oak wood staves and MOX) were bottled on the same day in 750 mL amber glass bottles (two bottles per modality). The cork stopper and the bottleneck were sealed with parafilm to prevent evaporation. The bottles were stored in the cellar of INIAV-Dois Portos. Sampling was carried out in the beginning and after 12 months of storage, and the phenolic compounds (gallic, syringic, ferulic and ellagic acids, vanillin, syringaldehyde, coniferaldehyde, sinapaldehyde, umbelliferone and scopoletin) were analysed by a HPLC method developed and validated in our laboratory.4
The ANOVA results revealed that most of the compounds’ contents did not change significantly after 12 months of storage in bottle. In addition, the phenolic differences between the WSs resulting from the four ageing modalities remained, except for ferulic acid. Therefore, in these experimental conditions, this stage allowed preserving the phenolic composition imparted to the WS by the alternative ageing technology.
Authors: Canas Sara1, Lourenço Sílvia1, Anjos Ofélia2 and Caldeira Ilda1
1Instituto Nacional de Investigação Agrária e Veterinária – Pólo de Dois Portos
2 Instituto Politécnico de Castelo Branco
*corresponding author: sara.canas@iniav.pt
References:
1 Canas S., 2017. Phenolic composition and related properties of aged wine spirits: Influence of barrel characteristics. A review. Beverages, 3, 55-76.
2 Canas S., Anjos O., Caldeira I., Belchior A.P., 2019. Phenolic profile and colour acquired by the wine spirit in the beginning of ageing: alternative technology using micro-oxygenation vs traditional technology. LWT – Food Science and Technology, 111, 260-269.
3 Granja-Soares J., Roque R., Cabrita M.J., Anjos O., Belchior A.P., Caldeira I., Canas S., 2020. Effect of innovative technology using staves and micro-oxygenation on the sensory and odorant profile of aged wine spirit. Food Chem., 333, 127450.
4 Canas S., Belchior A.P., Spranger M.I., Bruno de Sousa R., 2003. High-performance liquid chromatography method for analysis of phenolic acids, phenolic aldehydes and furanic derivatives in brandies. Development and validation. J. Sep. Sci., 26, 496–502.
Keywords: wine spirit, storage in bottle, ageing technology, phenolic compounds
