Interestingly enough, explains Mila

Interestingly enough, explains Milanowski, some of the grapes that have the highest glutathione content are varieties like colombard, chasselas and picpoul, varieties that are known to retain freshness even when they are grown in hot places. Conversely, varieties like grenache blanc and muscat have low glutathione ratios, and they generally tend to produce richer wines. The capacity of glutathione to sustain fresh, fruity aromas certainly seems to correlate with that