Chemical profiling and sensory analysis of wines from resistant hybrid grape cultivars vs conventional wines

Recently, there has been a shift toward sustainable wine production, according to EU policy (F2F and Green Deal), to reduce pesticide usage, improve workplace health and safety, and prevent the impacts of climate change. These trends have gained the interest of consumers and winemakers. The cultivation of disease resistant hybrid grape cultivars (DRHGC), known as ‘PIWI’ grapes can help with these objectives [1]. This study aimed to profile white and red wines produced from DRHGC in South Tyrol (Italy). Wines produced from DRHGCs were compared with conventional wines produced by the same wineries. The measured parameters were residual sugars, organic acids, alcohol content, pigments and other phenolics by LC-QqQ/MS, colorimetric indexes (CIELab); and volatile profiles (HS-SPME-GCxGC-ToF/MS [2]). The Projective Mapping (napping) sensory protocol and the RATA (rate-all-that-apply) method were used to provide rapid categorization and characterization of DRHGC and conventional wines using an internal panel of 19 assessors (aged 25-40 years old). Preliminary analytical results for red wines showed that diglucosylated and triglucosylated anthocyanins were most common, and they were present also as acetylated and p-coumaroylated esters. The profile of cyclic proanthocyanidins was investigated for the first time in PIWI wines, such us ‘Solaris’, ‘Bronner’, ‘Muskaris’, ‘Johanniter’, ‘Souvignier gris’, ‘Regent’, and ‘Cabernet Cortis’, and compared with conventional white and red wines.

The sensory attributes found in PIWI white wines were “tree fruit” (pear, green apple) in ‘Solaris’ and ‘Bronner’, “caramelized” (honey) and “floral” (rosewater) in ‘Muskaris’, “stone fruit” (peach) in ‘Johanniter’, and “woody” (oak and coffee) in ‘Souvignier gris’  In contrast, sensory attribute “vegetative” (green bell pepper) conventional wines was perceived more  in Pinot Blanc and Pinot Gris as conventional wines.

The combination of sensory evaluation, chemical analysis, and multivariate statistical methods provided a deeper and more complete understanding of the quality of the wines under investigation.

Acknowledgments: Wineries (Bolzano, Italy) are kindly acknowledged for providing the wines analyzed in this study.

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