Longer cluster hanging time improves grape and wine quality of Vitis vinifera L. Merlot impacted by grapevine red blotch disease

Authors: GIRADELLO, RAUL - University Of California, Davis; Rumbaugh, Arran; PERRY, ANJI - J Lohr Vineyards And Wines; HEYMANN, HILDEGARDE - University Of California, Davis; BRENNEMAN, CHARLES - University Of California, Davis; OBERHOLSTER, ANITA - University Of California, Davis

Submitted to: LWT - Food Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/6/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Grapevine red blotch virus (GRBV) is a recently discovered virus and a major concern for the wine industry. Prior research indicated that GRBV delays grape ripening reducing Brix and anthocyanin concentrations in grapes from infected vines, resulting in higher ethanol concentrations in wines made from healthy fruit compared to diseased vines, which impacted sensory properties. In this study, infected fruit (Vitis vinifera L. Merlot) was sequential harvested (in 2016 and 2017) and chaptalized (in 2017) to ameliorate the impact of GRBV on grape and final wine composition. Chemical parameters includings phenolic and volatile profiles of grapes and their subsequent wines were measured. Sensory properties were determined by descriptive analyses. Results demonstrated that GRBV decreased sugar accumulation and anthocyanin synthesis in grapes. Wines from GRBV grapes harvested at later ripening stage produced wines that were more similar chemically and sensorially to wines to wines made from healthy fruit than to wines made from GRBV fruit harvested earlier. The longer hang time of GRBV grapes is a potential strategy to mitigate the impacts of GRBV. However, chaptalization of diseased fruit must was inefficient at increasing similarities with wines made from healthy fruit.