‘Juice index’ offers potential as a predictive tool for wine composition

The ‘juice index’ database is the outcome of a Plant & Food Research-led programme to develop a unique metabolomics database of New Zealand Sauvignon blanc (SB) grape juices and their corresponding wines. 

The database, a collaboration between Plant & Food Research, academia and industry, is the first of its kind in the world to be made available to the scientific community and will help build better understanding of the different factors that contribute to variations in SB juices and wines, offering winemakers a potential tool to assist with managing and maintaining wine style. 

Winemakers know that wine composition can be varied through the application of traditional viticulture and winemaking tools. However, novel tools are more likely to be developed if the various factors influencing grape and wine composition are understood.

While SB grapes are widely grown in New Zealand, with the Marlborough region internationally reputed for a unique wine style, the consistent production of highly typical wines is challenging because their composition differs from season to season and between locations within a region. 

The ‘juice index’ database was created to acquire in-depth knowledge about the role of different factors – such as climate, soils, viticultural management and grape processing – on wine composition. The project was started in 2010 with the current dataset including samples from approximately 400 grape juices collected from different regions in New Zealand over three seasons between 2011 and 2013. 

With recent advancements in high resolution and sensitive analytical instruments, metabolomics shows enormous potential in the analysis of grape juice and wine. In this study, the comprehensive metabolite profiling of juices and wines was undertaken to create a database that could serve as a knowledge base not only for industry, but also for scientific community.  

This data-driven research suggests that seasonal variation is more prominent than regional or intra-regional difference in SB grape juices and wines, despite the widespread use of vineyard irrigation in New Zealand to mitigate seasonal rainfall and evapotranspiration differences. 

When combined with mathematical modelling, these datasets show great potential for building a predictive tool for wine composition and a platform for innovation. In addition to assisting in the production of wines of consistent composition, future applications could enable winemakers to tailor wines based on consumer preference.

The project was part of the Sauvignon blanc II programme, funded by the Ministry of Business, Innovation and Employment (MBIE) with co-funding from the New Zealand Winegrowers Inc. 

Journal Reference:

Pinu F, Tumanov S, Grose C, Raw V, Albright A, Stuart L, Villas‑Boas S, Martin D, Harker R, Greven M 2019 Juice Index: an integrated Sauvignon blanc grape and wine metabolomics database shows mainly seasonal differences, Metabolomics 15 (3). DOI: 10.1007/s11306-018-1469-y