Quercetin is a flavonoid that is produced in the skin of the grape under the influence of UV radiation. Quercetin is an anti-oxidant and yellow colorant (pigment) and protects the grape against the influence of excessive sunlight.
Quercetin is a flavonoid that is produced in the skin of the grape under the influence of UV radiation. Quercetin is an anti-oxidant and yellow colorant (pigment) and protects the grape against the influence of excessive sunlight.