Location: Horticultural Crops Research UnitTitle: Grape anthocyanin altered by absolute sunlight exclusion
Submitted to: Oregon Wine Research Institute
Publication Type: Abstract Only
Publication Acceptance Date: 3/23/2016
Publication Date: 3/29/2016
Citation: Lee, J. 2016. Grape anthocyanin altered by absolute sunlight exclusion. Oregon Wine Research Institute. OWRI (Oregon Wine Research Institute) grape day conference booklet p.7.
Technical Abstract: This research was conducted to clarify anthocyanin accumulation within ‘Merlot’ grapes in response to microclimate, specifically to light incidence, temperature, and humidity. Treatment grape clusters were light-excluded during ripening by opaque white polypropylene enclosures, during which light intensity, temperature, and humidity were continually measured. There were two controls and two treatments: control-shaded (Ctrl-SH; ambient), control-exposed (Ctrl-EX), light-excluded (Trt-LE), and aspirated light-excluded (Trt-ALE). All 15 ‘Merlot’ grape anthocyanins (previously reported) accrued in control and treatment clusters, indicating no accumulations were terminated from light exclusion during ripening. Treatment groups (both Trt-LE and Trt-ALE clusters) had less anthocyanin accumulation (86.8 mg/100g berry) than control clusters (160.2 mg/100g). The proportions of the individual anthocyanins were also altered by light exclusion. While Trt-ALE clusters had the lowest total anthocyanins (75.4 mg/100g), they did have a higher percentage of acylated anthocyanins (52% of the total) when compared to the other treatments (Ctrl-SH-36%, Ctrl-EX-37%, and Trt-LE-42%). Additional grape quality metabolites were also evaluated.