In the previous communication (l), it was shown that the free energy of the bivalent fumarate ion at 25” is -144,630 calories. In the present communication the measurement of the equilibrium at 25” between fumaric acid and malic acid in the presence of fumarase is reported, and from the values obtained computations are made of the free energy and heat of formation of the bivalent I-malate ion a...

Preliminary experiments have shown (1, 2) that, when excised tobacco leaves are cultured in the dark in 0.2 M solutions of potassium succinate or L-malate, a marked stimulation of the formation of citric acid occurs. Furthermore, leaves cultured in succinate increased in their content of malic acid, although culture in L-malate, in the single experiment that has been carried out (2), did not le...

Martelo-Vidal M.J., Vázquez M. (2014): Evaluation of ultraviolet, visible, and near infrared spectroscopy for the analysis of wine compounds. Czech J. Food Sci., 32: 37–47. Spectroscopy of UV-VIS-NIR combined with chemometric analyses was used as a non-destructive technique to build models for the quantitative characterisation of the main compounds of wine. The work in mixtures can give insight...

The experiment was carried out to investigate the effect of different concentrations of salicylic acid (SA), malic acid ( MA), citric acid (CA) and sucrose (Suc) on keeping quality and vase life of Chrysanthemum cut flowers. In this study three levels of malic acid (0, 100 and 150 mg l ) and salicylic acid (0, 1.5 and 3 mM) and two levels of sucrose (0 and 3% w/v) and of citric acid (0 and 150 ...

Nowadays, increasing use of latex products in the healthcare area has also led to an increase in new scientific controls of raw material and manufactured products in order to maintain higher standards in quality control. Since field latex is a rich environment for microbial growth, in the absence of adequate preservation, the carbohydrates that it contains become microbiologically oxidised to t...

The total acidity of orange juice is ordinarily determined by titrating a known volume of juice with a standard solution of NaOH, with phenolphthalein as indicator, the result beinog expressed as citric acid. This value includes all the substanees of an acidic nature in the juice that react with NaOH. It so happens, however, that in most fruits the chief substances reacting with NaOH are the or...

Schizosaccharomyces pombe is of interest to wine-makers because, unlike the Saccharomyces cerevisiae wine yeasts, it eciently metabolizes all levels of malic acid found in grape musts. To determine the metabolic pathway for malatemetabolism in Sch. pombe, a mutational analysis was performed using a selection system which isolated 154mutants that were unable to utilize malic acid. Themutants we...

The objectives of this study were to determinethe interactions between two hepatic enzymes and some minerals in the liver of broiler chickens. The study was performed with male and female from 1 to 56 days of age of broiler chickens. Malic acid was added to the water and offered to chickens freely from the start to the end of the experiment with constant concentration. The treatments consisted ...

Biomphalaria alexandrina snails play an indispensable role in transmission of schistosomiasis. Infection rates in field populations of snails are routinely determined by cercarial shedding neglecting prepatent snail infections, because of lack of a suitable method for diagnosis. The present study aimed at separation and quantification of oxalic, malic, acetic, pyruvic, and fumaric acids using i...