Ezekiel Warren and Misha Kwasniewski*
*The Pennsylvania State University, Rodney A. Erickson Food Science Building, State College, PA, 16803 (mtk5407@psu.edu)

Accentuated cut edges (ACE) is a relatively new method of fractioning the skins of grapes into smaller pieces to modify wine sensory characteristics. ACE increases the surface area of the skins touching the liquid, thus increasing the extraction of grape skin compounds. This method has been used to increase the polyphenol concentration in red wines. Work has primarily been done in red Vitis vinifera cultivars and little is known about its effects on the volatile composition of the final wine. Non-V. vinifera cultivars tend to have lower tannin concentrations, potentially allowing ACE to be an important tool in increasing this deficiency. Additionally, as skins are an important source of volatile compounds, there is potential to improve aromas in both red and white wines through this procedure. Two Pennsylvania hybrid red cultivars, Chambourcin and Noiret, were fermented in 20-L containers or microvinified depending on the vintage and five white cultivars were microvinified. Grapes were sampled over three vintages. Prior to fermentation, the grapes were either processed with ACE or not (control). Phenolic profiling of red wines was done using the Adams-Harbertson protein precipitation assay and all wine volatiles were profiled using gas chromatography-mass spectrometry solid phase microextraction (SPME). For the 2021 microinfarctions, both Chambourcin and Noiret had an increase in iron-reactive tannins from 2.27 to 6.93 and from 7.91 to 244.38 mg/L CE, respectively. For the same vintage, in the 20-L fermentations, ACE influenced the volatile composition. For example, the ethyl caprate concentration was affected due to ACE in both Chambourcin and Noiret, from 13.9 to 26.1 and 68.8 to 47.7 ng/mL, respectively. The mean concentration of β-damascenone across all white grape cultivars was found to be higher in ACE treatments. These results demonstrate that ACE can impact both phenolic and volatile compounds in these Pennsylvania hybrid cultivars.

Funding Support: Pennsylvania Wine Marketing and Research Board