fairly neutral, green aroma (Thompson
seedless), or be flowery and citrusy from
terpenes (muscat), or musky with anthranilate
and other esters (Concord and other American
varieties). Most commercial varieties today
have been bred to be seedless, crisp, tart, and
sweet, with a long storage life. Thompson
seedless grapes picked in the cool of the
morning and treated with antimicrobial sulfur
dioxide can be held for as long as two months
at 32ºF/0ºC.
Raisins Grapes are easily preserved by
sundrying to make raisins. In the United
States this is usually done by laying the
grapes on paper between rows in the vineyard
for about three weeks. Raisins are naturally
brown and have caramel flavor notes due to a
combination of browning-enzyme oxidation
of phenolic compounds and direct browning
reactions between sugars and amino acids (pp.
269, 778). Both of these processes are