16 research outputs found
Influence of yeast strains on phenolic composition and antioxidant activity of Vranec wines
No full textThe phenolic composition of ten autochthonous monovarietal Vranec red wines produced with different yeast strains was determined by HPLC-DAD analysis. Vranec wines were fermented with the following Saccharomyces cerevisiae yeast strains: Clos, RC212, D254, BDX (from Lallemand), and six Vinalco yeasts isolated from the Tikveš wine region (Republic of Macedonia). A total of 19 phenolic compounds were identified and quantified in wines and among them the malvidin-3-glucoside and its derivatives were the major compounds. Wines fermented with Vinalco yeast presented higher amount of anthocyanins as well as phenolic acids (hydroxycinnamic and hydroxybenozoic) compared to the wines fermented with Lallemand yeasts. The content of malvidin-3-glucoside in Vranec wines fermented with Vinalco yeasts ranged between 235–887 mg/L, whereas Vranec wines fermented with Lallemand yeasts contained 335 to 355 mg/L. The caftaric acid, the main cinnamic acid derivative in all wines, was found in concentration between 176–507 mg/L, followed by coutaric and fertaric acids (14–89 and 11–49 mg/L, respectively). Wines showed relatively high value of the antioxidant activity that ranged between 99–117 mg/L Trolox equivalents, regardless the yeast strain used for fermentation
Targeted analysis of bioactive phenolic compounds and antioxidant activity of Macedonian red wines
No full textPhenolic composition of twenty-two Macedonian red wines, including ten autochthonous monovarietal Vranec wines produced with different yeasts for fermentation, and twelve wines from international varieties (Syrah, Merlot and Cabernet Sauvignon) from different wine regions was studied. All wines presented relatively high value of total phenols and antioxidant activity. A total of 19 phenolic compounds were identified and quantified using HPLC-DAD and among them, malvidin-3-glucoside and its derivatives were the major compounds, followed by the petunidin derivatives, while caftaric acid was the predominant cinnamic acid derivative in all wines. The anthocyanin content was mainly affected by the grape variety and to a less extent by the yeast used in fermentation. In particular, the use of locally isolated yeasts affected higher amount of anthocyanins and phenolic acids compared to the wines fermented with commercial yeasts. Principal Component Analysis showed a satisfactory grouping of red wines according to the grape variety
YIELD AND MINERAL COMPOSITION OF GRAPEVINE AS AFFECTED BY MAGNESIUM AND IRON FOLIAR NUTRITION
No full textThe aim of this study was to evaluatefoliar fertilizers (Magni mag helat and Magni fer helat) effects on yield, quality parameters and nutrient contents of the leaves ofvine cultivarCardinal in comparison to control variant (without foliar fertilizer). Field trials has been organised according the method of random block system with three variants (including control variant I) in three repetitions. Foliar fertilizers were applied in concentration of 0.5 %, four times during the vegetation period (before and after blooming, buckshot berries and verasion).
Results for 3 years indicated that Mg and Fe fertilizers application affected the yield of grape and its quality. Fertilized Variant III had higher average yield with 14.87 t/ha.Foliar fertilizing with Fe has significant effect on increasing of: total cluster weight, berries weight per cluster and percentage of berries. Treated variants had a lower weight of skin and seeds, compared with the control.A substantial influence of foliar fertilizers on analysed element contents in leaves has been identified, also.The 3-years average content of macro and micro elements showed higher content of P (0.35 %), Ca (3.03 %), N (2.25 %), Mn (133.24 mg/kg) and Cu (18.18 mg/kg), at Variant II.Results of leaf tissue confirmed some antagonistic relations between analyzed elements, like: Fe/P, Mg/K and Fe/Mn.
Keywords: Cardinal,berries, element,fertilization,qualit
YIELD AND MINERAL COMPOSITION OF GRAPEVINE AS AFFECTED BY MAGNESIUM AND IRON FOLIAR NUTRITION
No full textThe aim of this study was to evaluatefoliar fertilizers (Magni mag helat and Magni fer helat) effects on yield, quality parameters and nutrient contents of the leaves ofvine cultivarCardinal in comparison to control variant (without foliar fertilizer). Field trials has been organised according the method of random block system with three variants (including control variant I) in three repetitions. Foliar fertilizers were applied in concentration of 0.5 %, four times during the vegetation period (before and after blooming, buckshot berries and verasion).
Results for 3 years indicated that Mg and Fe fertilizers application affected the yield of grape and its quality. Fertilized Variant III had higher average yield with 14.87 t/ha.Foliar fertilizing with Fe has significant effect on increasing of: total cluster weight, berries weight per cluster and percentage of berries. Treated variants had a lower weight of skin and seeds, compared with the control.A substantial influence of foliar fertilizers on analysed element contents in leaves has been identified, also.The 3-years average content of macro and micro elements showed higher content of P (0.35 %), Ca (3.03 %), N (2.25 %), Mn (133.24 mg/kg) and Cu (18.18 mg/kg), at Variant II.Results of leaf tissue confirmed some antagonistic relations between analyzed elements, like: Fe/P, Mg/K and Fe/Mn.
Keywords: Cardinal,berries, element,fertilization,qualit
Effect of foliar calcium and nitrogen treatments on yield and fruit quality of table grapes cv. 'Cardinal'
No full textThe foliar fertilization has been used as an important agrotechnical measure to avoid deficiencies and to improve quality. During the three consecutive years, a study has been performed on Vitis vinifera L. (cv. 'Cardinal') to examine whether a yield and grape berry quality have been affected by the foliar application of Ca and N fertilizers. A liquid mineral fertilizer containing 40% Ca(NO₃)₂ as Variant I and 31% N with 0,015 % Fe-chelate; 0,01 % Mg - chelat as Variant II (in text) has been sprayed four times during the growing period (before and after blooming, buckshot berries, and verasion). Results showed that foliar application of calcium and nitrogen increased the yield of table grapes in all three years of research, in comparison with a control variant. The highest yields of grapes in all three years of investigations were achieved in Variant II - 4.57 kg/vine (14.85 t/ha). During the tree years of investigations, the largest mass of grape bunch and berries were recorded in Variant II (382g and 368.68g), while the lowest cluster weight was in the control variant (344g and 330.92g). With a reference to the mechanical properties of the grape berries, the highest resistance to pressure (2229.70g) and breaking resistance (364.52g) were found in Variant I, treated with Ca fertilizer. The foliar application significantly affects the mechanical properties (resistance of the berry to pressure and breaking), especially in Variant I. The application of different types of foliar fertilizers did not have any significant effect on sugar contents and total acids, compared with the control varian
Natural radioactivity and human exposure by raw materials and end product from cement industry used as building materials
No full textDuring the manufacturing process in the cement industry, raw materials of different levels of natural
radioactivity are utilized. In this study we present the radiological impact of cements as a building
material and the different raw materials used in their manufacture. A total of 218 samples of raw
materials and their end product cements were collected from the cement industry of Macedonia (The
Former Yugoslav Republic) during the period 2005e2007. The specific activities, evaluated by gamma
spectrometry analysis, showed the highest mean specific activity in fly ash (226Ra, 107� 45 Bq kg�1;
232Th, 109 � 30 Bq kg�1; 40K, 685 � 171 Bq kg�1), which is used as a raw material. However, the final
cement product usually has relatively lower activity compared with the activity of the raw material and
the mean specific activity of the final cement products were lower (226Ra, 42 � 10 Bq kg�1; 232Th, 28
�6 Bqkg�1; 40K, 264 � 50 Bq kg�1). The radium equivalent activity and the hazard index were calculated
for each sample to assess the radiation hazard. The mean annual effective dose originating from the
cements was found to be 111 � 22 mSv y�1, which is below the recommended EC limit of 300 mSv y
Production of a new diary product enriched with antioxidants from grape pomace and berries
No full textThe purpose of this study was to introduce a new source of antioxidants obtained from grape pomace as well as aronia and blueberry and engages them in preparation of a new yoghurt product in order to be last – longer and more beneficial for human health than the traditional one. Totally, grape pomaces from 4 varieties (Zupjanka, Prokupec, Kadinal and Vranec), as well as blueberry and aronia, were used. For the extraction of polyphenolics, liquid-liquid extraction with ethanol/water/acetic acid was used, followed by roto-evaporation, in order to concentrate the extracts and then to introduce them into the milk. The total phenolic content of the extracts was determined by the Folin-Ciocalteu method and the total anthocyanins were analyzed by dilution of the samples with ethanol/water/HCl, obtaining three different volumes of extracts (10, 50 and 100 mL) of each sample (grape pomaces, blueberry and aronia), obtaining 36 extracts in total. The three different concentrates of each sample (18 in total) were applied on milk together with the lactic bacteria in order to study the influence of polyphenolics during the fermentation; as well as, 18 other extracts applied on milk after the fermentation (into the obtained yoghurt). The pH value of the newly generated yoghurts was analyzed during the fermentation and storage.
The aronia sample presented highest phenolic content (431 mg/L), while Zupjanka had the lowest content of polyphenols (67.9 mg/L). The grape pomace presenting best results was Prokupec (246 mg/L). All yoghurt samples containing polyphenolics applied before the fermentation, presented higher pH value compared to the control and samples with polyphenolics applied after fermentation. Furthermore, all yoghurt samples containing phenolics extract with highest concentration, showed best results, presenting stable pH value. Sensory analysis was performed on the different yoghurt samples, concluding that the new products have creamy texture, good taste, without unpleasant smell or bitterness. The colour of some samples turned into red-violet, excluding the yoghurt with extracts from: Zupjanka and Kardinal. By microbiological analysis the presence of pathogen and other harmful bacterias was proved to be negative, showing that this yoghurt is a main basis for manufacturing of a more beneficial dairy product that could be soon available on the market
A new Macedonian novel about a young and growing
No full textIn this paper we refer to a new, in fact the latest novel by Macedonian author of children Velko Nedelkovski dedicated to young readers. What makes this book special is that it applies to young people who are at the exit from childhood and the threshold of adolescence, and the author attempted to help them on that rocky road through friendships, initial loves, nourishing love to animals, respect for elders, and all this in order to grow into healthy, strong young men, ready to face all difficulties in life
Potential and possibilities of rebo – new grapevine variety (Vitis vinifera L.) in growing conditions in Republic of North Macedonia
No full textRebo (Rigotti 107-3) is a vine variety that originates from Trentino, North Italy. It was selected by the
researcher Rebo Rigotti by crossing the varieties Merlot x Terlodego at the agriculture and forest experimental
station in S. Michele all’ Adige. According to the literature the idea of the breeder was to produce new
variety that would be similar to Merlot but more resistant to cold climate conditions. Our idea to plant Rebo
in Macedonia was to grow this variety on sites with higher altitude locations that are difficult for growing
Merlot. The vineyard for this study is located in the north part of Macedonia on the mountain German near the
town of Kriva Palanka, area typical for growing frost resistant varieties. In this research paper we analyzed the
mechanical structure of the grape cluster and berries, the quantity of sugar and titratable acids in the grapes.
In the wine we analyzed the quantity of total phenols, total anthocyanins, wine colour (CI;H), total flavan-3-ols
and standard chemical analysis of the wine
Application of Grape Pomace as a Natural Food Preservative and Source of Biofuel
No full textThe aim of this work is utilization of the grape pomace piled up as a waste after winemaking and its application in producing biodiesel. Furthermore, a novel yoghurt product was produced, enriched with antioxidants, such as polyphenolics from the grape pomace and berries in order to improve its nutritional value, contributing to food preservation and significantly reducing the risk of diseases. In fact, for the first time we engaged these compounds in preparation of a new yoghurt product,
that proved to be last longer and more beneficial for human health than the traditional one, since the antioxidants play a great role in the prevention of cardiovascular disease, cancer etc. Furthermore, a cost-
effective, easily made and environmentally friendly biodiesel was produced, that could represent an alternative to the old fossil petroleum to replace it and resolve the present energy crisis
