Aromatic Profile and Phenolic Composition of White Wines from Hybrid Grapes Grown onto Different Rootstocks and Regions of Brazil

This study investigated the phenolic and aromatic composition of wines produced from four white grape cultivars grafted onto two rootstocks grown in two distinct regions of São Paulo, Brazil: Votuporanga and Jundiaí. Wines made from Moscato Embrapa (ME) and Moscatel de Jundiaí (MJ) cultivars exhibited the highest total phenolic contents, averaging 278.91 and 238.94 mg/L, respectively. Environmental factors influenced phenolic accumulation, with higher concentrations generally observed in wines from Votuporanga. In contrast, IAC Madalena and IAC Ribas cultivars showed greater stability across sites and rootstocks, with minimal variation in phenolic content. Aromatic composition analysis revealed esters as the dominant volatile class, particularly ethyl octanoate, ethyl decanoate, and ethyl hexanoate, which contribute to the wine's fruity and floral characteristics. Some volatiles, such as terpinolene and isoamyl acetate, showed cultivar-specific occurrence, affecting sensory characteristics. Principal component analysis (PCA) of volatile organic compounds demonstrated that genetic factors had a stronger influence than environmental or rootstock variables, with apparent clustering by cultivar. High-performance liquid chromatography with diode array detection (HPLC-DAD) identified phenolic acids as the most abundant compounds, with Moscato Embrapa wines showing the highest concentrations, especially caftaric acid. <i>cis</i>-resveratrol, a bioactive stilbene, was notably present only in IAC Ribas and IAC Madalena wines. PCA of phenolic compounds further supported the predominance of genetic influence on wine composition, with limited impact from location or rootstock. Overall, the results emphasize that the phenolic and aromatic profiles of wines produced from white grapes are primarily determined by the genetic makeup of the cultivars, with environmental conditions and rootstock playing secondary roles. These findings have implications for grape selection and vineyard management aimed at producing wines with desired chemical and sensory characteristics.