Abstract

CARVALHO, Estrela C.P.; COSTA, Susana; FRANCO, Claudia  and  CURVELO-GARCIA, A.S.. Musts and wines acidification. L(+)-lactic acid as an alternative to L(+)-tartaric acid . Ciência Téc. Vitiv. [online]. 1999, vol.14, n.2, pp.67-77. ISSN 0254-0223.

It’s comparatively studied the white musts and wines and the red wines acidification by two acidifying agents: L(+)-tartaric acid and L(+)-lactic acid. The acidification level utilised is 22 meq/L. It’s verified that acidification with L(+)-lactic acid minimise the occurrence of potassium hydrogenotartrate precipitation, meaning comparatively an effective reduction of the expected acidifying strength of L(+)-tartaric acid taking into consideration the pK values of these acids. In some cases (white wines acidification), L(+)-lactic acid even present a better efficacy to increase the total acidity that L(+)-tartaric, but no to decrease the pH. Concerning the white musts and wines acidification, the decreasing of pH is more efficient with L(+)-tartaric acid and bigger when used in wines. On the other hand, the increasing of total acidity is more important using L(+)-lactic acid and bigger when applying in musts (before the fermentation). In red wines acidification, it’s showed that the increasing of total acidity is the same (using L(+)-tartaric or L(+)-lactic acids) and the decreasing of pH is greater when the L(+)-tartaric is used, but not in correspondence with their pK values. The reasons are the same: the precipitations of potassium hydrogenotartrate induced by the L(+)-tartaric acid acidification. The sensorial analysis confirm these conclusions, showing however that there isn’t significative differences of general evaluation between the wines resulting of the different acidification procedures. Neither of these acidifying agents cause immediately calcium tartrate precipitations, expected fact considering the known kinetics of these precipitations.

Keywords : Mostos e vinhos; acidificação; ácido L(+)-láctico; ácido L(+)-tartárico.

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