The influence of leaf area and various variants of manual defoliation on the phenolic profile of the Prokupac variety grape berry were investigated in the agroecological conditions of southern Serbia. The following four trial variants of manual defoliation were assessed: Early defoliation-variant I (flowering stage, 50% open flowers); early defoliation-variant II (grape size 3-5 mm); late defoliation-variant III (onset of grape ripening, veraison); and control (no defoliation). The first six leaves of each primary shoot were removed from all defoliated vines. The greatest assimilation area of primary and lateral shoots during the study was observed in the control, i.e., the trial variant with no defoliation. Defoliation significantly decreased the grape yield of the all three defoliated variants in regard to the control. The phenolic profile of the three variants and control was established by analyzing the grape seeds and skin. Based on the collected results for the Prokupac variety, significant differences between the trial variants were established regarding the content of phenols and total polyphenols, as well as radical scavenging activity. Defoliation variants showed a significant effect on the total phenols content of grape skin. In all defoliation variants, as well as in the control, high amounts of ellagic acid were measured. Resveratrol was identified only in grape skin samples of the control variant. The removal of leaves increased the concentration of phenolic compounds in variants where early defoliation was applied. The highest total anthocyanins content was found in 2015 in variant I, where leaves were removed during the full flowering stage.

Grape brandy, known as ‘Lozovača’, is one of the most produced alcoholic beverages in the Republic of Serbia. Muscat cultivars are highly priced in grape brandy manufacturing. Among the numerous factors, cultivar-specific characteristics have a significant influence on its quality and aroma profile. Pectolytic enzymes play a part in increasing intensity of the prefermentative aroma by hydrolysis of terpenic glycosides, from which the compounds that contribute to the aroma of brandy are released. In this study, grape brandy samples were produced from five Muscat table grapevine cultivars (Vitis vinifera L.) namely, Early Muscat, Radmilovac Muscat, Banat Muscat, Italia Muscat, and Muscat Hamburg, with the addition of pectolytic enzyme in two different concentrations or without it (control). A total of 58 volatile aroma compounds were detected by means of combined gas chromatographic-mass spectrometric (GC/MS) method. Ethyl esters of C8–C18 fatty acids (21) and terpene (16) compounds were considerably more abundant in all grape brandy samples compared to the other volatile compounds identified. Pectolytic enzyme, positively affected terpenes content in the brandy of all studied cultivars. The similarities between brandy samples produced from Muscat Hamburg (MH) and other Muscat cultivars may be attributed to the parentage of MH to those cultivars.

Suitability of bentonite clay modified with sodium carboxymethyl cellulose (Na-CMC) for the removal of arsenic(III) ions from aqueous solution was tested in batch adsorption studies and complemented by theoretical modeling with Langmuir, Freundlich and Temkin isotherm models. The effects of various factors, such as the initial adsorbate concentrations, pH, and temperature of the solutions were investigated in series of experiments. FTIR analysis was used to detect functional groups typical for cellulose and bentonite. Scanning electron microscope was used to analyze the surface morphology of the composites. It was established that the removal process was fast in the beginning and adsorption equilibrium was attained in around 20 minutes with good fittings to both Langmuir and Freundlich model. Maximum adsorption capacity (Qmax) obtained from experiments was 9.4 mg/g. No influence of solution pH and temperature on the sorption was noticed. The series of conducted experiments showed that synthesized composites are suitable for the removal of arsenic from wastewaters by adsorption as efficient and low-cost technique.

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A comparative study of different pruning ways and bud load, as well as their influence on growth, yield and quality of Rhine Riesling B-21, Riesling Italian, and Zupljanka vine cultivars in the conditions of the Rasina vine district, during the period 2000 - 2001, is given in this paper. This research results have shown that grape yield and quality varied, and the greatest grape yield was observed in the variant with the greatest bud load. The Rhine Riesling B-21 demonstrated the best results. It should be pointed out that bud load per vine had a much greater influence on the studied traits than the applied way of pruning.