Ultrasonic monitoring of malolactic fermentation in red wines.

Ultrasonics (2014-05-06)
D Novoa-Díaz, J M Rodríguez-Nogales, E Fernández-Fernández, J Vila-Crespo, J García-Álvarez, M A Amer, J A Chávez, A Turó, M J García-Hernández, J Salazar
ABSTRACT

The progress of malolactic fermentation in red wines has been monitored by using ultrasonic techniques. The evolution of ultrasonic velocity of a tone burst 1MHz longitudinal wave was measured, analyzed and compared to those parameters of oenological interest obtained simultaneously by analytical methods. Semi-industrial tanks were used during measurements pretending to be in real industrial conditions. Results showed that the ultrasonic velocity mainly changes as a result of the conversion by lactic acid bacteria of malic acid into lactic acid and CO2. Overall, the present study has demonstrated the potential of the ultrasonic technique in monitoring the malolactic fermentation process.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Lactic acid solution, ACS reagent, ≥85%
Sigma-Aldrich
Lactic acid, 85%, FCC
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DL-Lactic acid, ~90% (T)
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DL-Malic acid, ReagentPlus®, ≥99%
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Lactic acid, meets USP testing specifications
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Supelco
Malic acid, Pharmaceutical Secondary Standard; Certified Reference Material
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DL-Malic acid, ≥98% (capillary GC)
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Malic acid, meets USP/NF testing specifications
USP
Lactic acid, United States Pharmacopeia (USP) Reference Standard
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L-(−)-Malic acid disodium salt, ≥95% (titration)
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DL-Malic acid disodium salt, ≥95% (capillary GC)
Sigma-Aldrich
DL-Malic acid, meets analytical specification of FCC, E296, 99-100.5% (alkalimetric)