Lindsay Garcia, Sarah Caballero, Jooyeoun Jung, Yanyun Zhao, 
and Elizabeth Tomasino*
*Oregon State University, 3051 SW Campus Way, Corvallis, OR, 97331 (elizabeth.tomasino@oregonstate.edu)

The growing concern of wildfire smoke affecting winegrapes around the world has triggered an immediate need to develop mitigation techniques. Smoke exposure can lead to negative qualities in finished wine. Current remediation strategies have not been effective in removing smoke taint in wine. One promising technique is spraying winegrapes with cellulose nanofiber-based films (CNF) prior to a smoke event. Previous research has shown that when these films were applied in the field before smoke exposure, the resulting grapes had lower concentrations of guaiacol, 4-methylguaiacol, syringol, and 4-methylsyringol when compared to grapes with no films. This study aims to analyze the diffusion capabilities of the volatile phenols through the films. Four different film types were analyzed. To a base of CNF, different quantities of chitosan and/or β-cyclodextrin were added. Each film was placed inside a custom-made polytetrafluoroethylene two-piece chamber. The bottom piece of the chamber contained a volatile phenol, and the film was placed in the middle of the chamber. Headspace samples were removed from the top of the chamber. Samples were analyzed using gas chromatography-mass spectrometry. Differences between diffusion permeability of different phenols were found based on film type. Modifications can be made to current films to prevent a wider range of smoke compounds from being absorbed by winegrapes. Results from this study are critical in developing coatings that can prevent smoke compounds from entering grapes, should a wildfire occur.

Funding Support: USDA-SCRI [Grant no. 2021-51181-35862/Project accession no. 1027470] and the Oregon Department of Agriculture