A microcalorimetric sensor for food and cosmetic analyses: l-Malic acid determination.
Enzymatic microcalorimetry has been successfully employed in the reliable determination of the l-malic acid concentration in some foods and cosmetic products. The l-malic acid concentration during the wine-making process is particularly useful in order to control the progress of the malo-lactic fermentation. Total acidity, taste and flavour characteristics of wine depend on the l-malic acid quantity still present. To point out the analytical methodology the dehydration process of l-malic acid, in the presence of Fumarase enzyme, has been used. The new method has been compared with a common spectrophotometric one. By the proposed calorimetric method the l-malic acid concentration in different types of food (white and red wines, fruits and soft beverages) has been determined. In some cosmetic products too the l-malic acid was quantified. The method outlined resulted simple, direct and reliable (good accuracy and precision), in particular it does not require any pre-treatment or clean up of the samples, save the dilution in buffer.
Antonelli
Marta Letizia
ML
Dipartimento di Chimica, Università degli Studi di Roma "La Sapienza", Piazzale Aldo Moro, 5, 00185 Rome, Italy.
Spadaro
Claudio
C
Tornelli
Rosalia Fortunata
RF
D002151:Calorimetry / Q000379:methods* / Q000639:trends*; D003358:Cosmetics / Q000032:analysis; D005285:Fermentation; D005504:Food Analysis / Q000379:methods* / Q000592:standards; D005649:Fumarate Hydratase / Q000378:metabolism; D008293:Malates / Q000032:analysis* / Q000378:metabolism; D008832:Microchemistry; D014920:Wine / Q000032:analysis
D003358:Cosmetics; D008293:Malates; C030298:malic acid; D005649:Fumarate Hydratase