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• Optimization of sample preparation for determination of antioxidant parameters from one grape berry

  93-97.

  Gy. Lukácsy

  É. Stefanovits-Bányai

  N. Papp

  L. Kocsis

  Views:

  222

  Berry quality is an important issue in wineprocessing, however evaluating characteristics in a single berry level is very complex. The Phenolic compound analysis is more challenging because of the limited amount of material and a mixture of skin, pulp and seed. No clear protocol exists for evaluating these compounds from single berries. The aim of our investigation was to develop such a protocol. Single whole grape berries samples were homogenized in 20 replicates by 5 different methods. The most effective method was when berry was placed in a mortar and was crushed with a pestle under liquid nitrogen until seeds were clearly visible. Seeds were then taken from the mortar and crushed between two stainless steel plates with a hammer, and returned to the mortar without residues. Homogenization continued until the sample had a powdery appearance. The homogenized samples were taken for further analysis such as total polyphenols, total anthocyanin contents and total antioxidant capacity. Our results demonstrate that single berries could be processed and that the homogenates were suitable for taking chemically uniform subsamples.

• Effect of the terroir and the harvest time on the Kékfrankos grape berries visual and physical parameters in Eger (Hungary)

  81-85.

  Z. Barócsi

  Views:

  164

  In this research, the effects of the “terroir” and the harvest time on the most important physical properties of the berries of Kékfrankos (Blaufrankish) grape variety were examined in 2010 and 2011. The results of the experimentation shown, that the maturation processes can be well described by different physical parameters of the grape berry. The terroir and harvest time effects were investigated in two different vintages and four different territories. It can be concluded, that these physical parameters change significantly during the ripening period, but trends differ between vintages and regions.

• Effect of the terroir and the harvest time on the Kékfrankos grape berries sensorial properties in Eger (Hungary)

  87-92.

  Z. Barócsi

  Views:

  198

  In this research the effects of the production site “terroir” and the harvest time on the most important organoleptic properties of the berries of Kékfrankos (Blaufrankish) grape variety were observed. The follow-up of the maturation process in a given parcel can effectively supplemented by the results of sensorial evaluations of the grape berries. In most cases, the tasters found significant differences in sensorial characteristics of the berries due to the harvest time, although the trends of each parcels were different. Significant differences were frequently found in the result of the observed terroirs.

• Study on the yeast and mould biota of the botrytized grapes in Tokaj region in two years

  61-65.

  Zs. Bene

  I. Magyar

  Views:

  181

  The famous wine Tokaji Aszú is produced from "noble rotted" grapes infected and modified by Botrytis cinerea under special condition. The objective of this study was quantitative and qualitative characterisation of saprophytic fungi present on the surface of aszú­berries, with special regard to yeasts. There were considerable differences in these populations depending on the origin of noble rotted berries, notably between berries taken from the vine or the ones taken from the winery. Beside Botrytis, other mould species like Penicillium, Aspergillus were commonly found, in widely varying population. Yeast counts were detected between 10⁴ and 10⁷ cfu/g berry. In the samples taken from the vineyard Candida pulcherrima predominated followed by some aerobic basidiomycetous species, but Hanseniaspora species were also present in relatively high population. After transport and storage of the grape in the wineries, population of aerobic yeasts and C. pulcherrima quickly declined and Candida stellata followed by other sugar tolerant species became dominant. This autoselection process directs attention to the importance of storage conditions.