Ninoslav Nikicevic

Possibilities for methanol content reduction in plum brandy

Several methods for reducing the methanol content of plum brandies were tried: possibilities for its reduced forming during fruit must alcohol fermentation, and employing effective and rational methods in order to decrease the already existing amount of methanol by applying demethanolization column. Apart from numerous valued components, plum brandy also contains some undesirable ingredients, among which methanol has a special place. It appears during hydrolysis of pectin substances under the influence of the specific pectolytic enzymes, pectyn-methyl-esterasis in particular. A certain amount still has to be present in natural brandies in order to maintain the authentic fruit origin. Reduction of the existing methanol amounts by applying demethanolization column was most effective and came to 43-77% in comparison to the starting amount.

Heavy metals content in Serbian old plum brandies

Seven elements, namely, arsenic, lead, cadmium, copper, zinc, iron and manganese were determined in 31 samples of Serbian plum brandies by applying atomic spectrometry techniques. Flame atomic absorption spectrometry was used for quantification of copper, iron, zinc, manganese, lead and cadmium; and hydride generation atomic spectrometry absorption for arsenic quantification. Measured concentrations of heavy metals and arsenic was assessed according to the Serbian regulations, official regulations of some other countries and in respect of microelements content in other similar distilled alcoholic beverages. Amounts of microelements in maximal recommended daily and weekly intake of plum brandy were determined. The influence of production (home made and industrial), type of wooden barrel (oak and mulberry), and duration of ageing process on the content of Zn, Cu, Fe and Mn in plum brandies, as well as coefficient of correlation between Cu content and pH value were also studied. [Projekat Ministarstva nauke Republike Srbije, br. 172053]

Raspberry wine fermentation with suspended and immobilized yeast cells of two strains of Saccharomyces cerevisiae

The objectives of this study were to assess the differences in fermentative behaviour of two different strains of Saccharomyces cerevisiae (EC1118 and RC212) and to determine the differences in composition and sensory properties of raspberry wines fermented with immobilized and suspended yeast cells of both strains at 15 °C. Analyses of aroma compounds, glycerol, acetic acid and ethanol, as well as the kinetics of fermentation and a sensory evaluation of the wines, were performed. All fermentations with immobilized yeast cells had a shorter lag phase and faster utilization of sugars and ethanol production than those fermented with suspended cells. Slower fermentation kinetics were observed in all the samples that were fermented with strain RC212 (suspended and immobilized) than in samples fermented with strain EC1118. Significantly higher amounts of acetic acid were detected in all samples fermented with strain RC212 than in those fermented with strain EC1118 (0.282 and 0.602 g/l, respectively). Slightly higher amounts of glycerol were observed in samples fermented with strain EC1118 than in those fermented with strain RC212. Copyright

Development and validation of LC-MS/MS method with multiple reactions monitoring mode for quantification of vanillin and syringaldehyde in plum brandies

An ultra-performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-QqQ-MS/MS) method with multiple reactions monitoring mode (MRM) has been developed and validated for quantification of vanillin and syringaldehyde in plum brandy. The method showed good linearity (0.05 to 10 mgL−1) and low limits of detection and quantification (LOD and LOQ were 11.6 µgL−1 and 38.2 µgL−1 for vanillin, and 12.7 µgL−1 and 42.0 µgL−1 for syringaldehyde, respectively). The overall intra-day and inter-day variations were less than 4.21%, and the overall recovery over 93.0%. The correlation coefficients (R2) of the calibration curves were higher than 0.9999. In order to evaluate if the method is suitable for use as a routine analytical tool, in 31 Serbian plum brandy samples vanillin and syringaldehide were determined. [Projekat Ministarstva nauke Republike Srbije, br. 172053]