%0 Journal Article %A DOUGLAS O. ADAMS %A CHANDRIKA LIYANAGE %T Glutathione Increases in Grape Berries at the Onset of Ripening %D 1993 %R 10.5344/ajev.1993.44.3.333 %J American Journal of Enology and Viticulture %P 333-338 %V 44 %N 3 %X Glutathione (GSH) was measured in grape (Vitis vinifera L.) berries during ripening. The Thompson Seedless variety was studied during two consecutive seasons from just before the onset of sugar accumulation until the berries attained commercial maturity. The GSH content increased along with soluble solids in both years. From Julian day 173 to day 197 in 1990 (21 June to 15 July), the GSH increased from 28.8 nmoles/gFW to 319 nmoles/ gFW. The average fresh weight of the berries increased from 0.79 g/berry to 1.95 g/berry during this period, so the GSH increase on a per berry basis was 22.4 nmoles/berry to 639 nmoles/berry. An increase in GSH was also observed in berries of Perlette, another seedless table grape variety. Beauty Seedless, a red variety, showed a gain in GSH accompanying the increase in soluble solids which began with the onset of pigmentation. Pigmented berries on a turning cluster showed higher GSH than green berries on the same cluster. Likewise, a seeded wine variety (Cabernet Sauvignon) had more GSH in berries with higher soluble solids, and more in pigmented berries on a turning cluster than in green berries from the same cluster. The results show that there is an increase in glutathione at the onset of ripening in grape berries. The increase was observed in red, green, seeded and seedless varieties, so GSH accumulation may be a general feature of grape berry ripening. The source of the GSH and a possible explanation for the timing of this phenomenon is discussed. %U https://www.ajevonline.org/content/ajev/44/3/333.full.pdf