Abstract
The aim of this thesis was to study sustainability and authenticity in wine production in South Tyrol, Italy. The thesis is divided into six chapters, starting with an introductory chapter and ending with a concluding chapter. The second chapter is a literature review of the use of disease resistant hybrid grape cultivars (DRHGCs) for wine production. DRHGCs offer many advantages to the wine industry, including the potential to reduce pesticide usage – a key issue for improving the sustainability of wine production. However, they have a number of disadvantages, most notably their unusual chemical and sensory properties. This review examined the chemical and sensory properties of DRHGCs, and reviewed methods suggested for optimising wine production with DRHGCs. The third chapter examined the chemical and sensory properties of DRHGC red wines produced in South Tyrol and compared these with Vitis vinifera wines from the same region. This study found that red DRHGC and V. vinifera wines were distinctive in terms of their chemical and sensory profiles. The anthocyanin profile of DRHGC red wines was particularly distinctive. The fourth chapter examines the influence of ultrasound technology on a bottled red wine that had already been aged for five years. Differences in the anthocyanin, polyphenol, proanthocyanidin, and volatile profiles were noted. The ultrasound treatment was rated highly for overall quality in the sensory analysis at month 6. It is suggested that six months treatment is optimal, and that the low energy treatment might be preferable. The fifth chapter looked at the distinctiveness of ‘Gewürztraminer’ wines from the village of Termeno sulla strada del vino – Tramin an der Weinstraße in South Tyrol. Vitis vinifera L. ‘Gewürztraminer’ is known for producing distinctive, aromatic wines that are strongly influenced by their terroir. It used a data-driven, metabolomic approach to objectively correlate terroir with chemical and sensory wine data. It analysed wine from seven Gewürztraminer vineyards near the village of Tramin that had been chosen to avoid variability due to climate differences. The vineyards were clustered into two groups based on soil data, clay silicate (Group A) and dolomitic (Group B) soils. Group A exhibited lower levels of aromatic compounds such as linalool and higher levels of phenolic compounds such as gallocatechin than Group B. These results suggest that even small changes in terroir can strongly affect ‘Gewürztraminer’ wines.