Search

Search Results

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

  61-65.

  Zs. Bene

  I. Magyar

  Views:

  157

  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.

• Epiphytic microbiota of apple in integrated and organic growing

  85-89.

  Sz. Pintér

  J. Benczer

  Z. Szabó

  J. Nyéki

  Views:

  168

  The surface microbial contamination is of great interest in case of fruits, since they are they potential sources of spoilage or foodborne diseases. The aim of this work was to compare the epiphytic microbiota of food safety concern of different apple cultivars as a function of cultivation methods (organic versus integrated), production year and place. Investigating 47 samples it was found that the average microbial contamination of the apple surfaces was within a certain range,, practically independent of cultivar, growing area and year. The frequency distribution of the surface bacterial, mould and yeast counts did not show significant differences between growing technologies or varieties. The principal component analysis the samples ranked the apple samples into seven groups on the basis of their microbial contamination level, and the discriminant analysis proved the goodness of grouping. The grouping was independent from cultivars and growing methods. No foodborne pathogen Salmonella spp. and Listeria spp. were found on the surfaces of apples.

• Investigation of the Relationship between the SO2 Production of Different Yeast Strains and Thiamine Concentration

  57-62.

  B. Pühra (Boróczki)

  M. Kállay

  K. Korány

  Views:

  137

  Our general conclusion was that the thiamine amounts of 0,6 and 3,0 mg/1 added prior to wine fermentation, resulted in higher free-S0₂ level in comparison to the control. Furthermore, among the yeast strains examined in our experiments, Uvaferm BC strain produced the highest free-S0₂ content under the conditions mentioned before. As regards the dynamics of reductone and SO, production, the concentration of the previous one was practically identical in the middle and at the end of the fermentation while the SO₂ content — both free- and total — was lower at the end. Thiamine addition did not cause any difference in the organoleptic properties of wines as proved by sensory analysis.