Agriculturae Conspectus Scientificus, Vol 66, No 4 (2001)

Changes of Sugar, Acids and Glycerol Content in Must from Late-Harvested and Botrytis cinerea Infected Graševina Grapes

Pavica TUPAJIĆ

Pages: 217-223

Summary


The composition of musts from Vitis vinifera L. cv. Graševina white grapes originating from vineyard region Continental Croatia, Kutjevo vineyard of vintage years 1997, 1998 and 1999 were examined. The musts were produced from grapes of different maturity grade, as well as Botrytis cinerea infection level, performed into 4 variants: ripe grapes, overripe late-harvested grapes, selected harvest berries, selected harvest dry berries. Musts were analyzed as to their density, pH values, total acidity and the content of glucose, fructose, citric, tartaric, malic, gluconic acids and glycerol. Compared to musts obtained from ripe grapes, all Prädikat musts contained higher quantities of glucose and fructose, higher pH values and higher content of glycerol. The most of Prädikat musts contained lower quantities of tartaric acid. The marked increase of total acidity was found only in musts from selected dry berries. The increase of concentrations of malic, gluconic, citric acids and glycerol were markedly pronounced in musts obtained from selected harvest berries and selected harvest dry berries. In musts of different years of harvest the differences in concentrations of gluconic and citric acids, as well as in glucose/fructose and glycerol/gluconic acid ratios were established.

Keywords


late harvest; Botrytis cinerea; must composition; organic acids; glycerol

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