Search

Search Results

• Determination of biogenic amine - content of natural wines

  91-95.

  M. Kállay

  D. Sárdy

  Views:

  191

  Nowadays the consumption of natural wines has been increased. In parallel with the higher demand, the study of the parameters of natural wines has also developed. The amines being produced during the decarboxylization procedure of amino acids could be one of the most important features of natural wines. The objective of this study was to measure the biogenic amine content of natural wines from 2000 and 2001. We have determined that the biogenic amine content of natural wines is not different from the biogenic amine composition of normal wines. There was not any considerable difference between the years. In complience with the average tendency, red wines contain higher histamine-, tiramine- and serotonin values than white wines.

• Maceration affects mineral composition and pH of wines

  25-29.

  N. Rakonczás

  D. Andrási

  Z. Murányi

  Views:

  298

  Mineral composition of wines is affected by many ecological and technological factors. These variables are mostly discussed focusing on certification of origin and human health. This paper gives data on possible changes in mineral composition and pH of wines due to 4 hours skin maceration (1st trial) and fermentation sur marc (2nd trial). Experimental site is situated on acidic sandy soil in middle east Hungary. The variety collection was established in 2003 with own rooted planting material in 3x1 m spacing, trained for single curtain training
  system. Mineral composition of wines was determined with ThermoFischer Scientific iCAP 6300 ICP-OES, pH was measured with pH10pen (VWR International) in field, and with SevenEasyTM pH meter (Mettler Toledo) in laboratory. 1st trial with 9 PIWI white wine grape varieties pointed to demonstrate effects of skin maceration, which is abundantly used to elevate aroma content. 2nd trial with the use of ‘Medina’ red PIWI grape variety aimed to demonstrate effects of double pasta skin maceration in rose and red wine technology. Data of 1st trial show, that K, Cu, Mn and P respective increase with skin maceration, despite Fe show considerable decrease. Data of 2nd trial show, that K, Mg, Mn, P, Sr and B increase with longer skin contact and higher fermentation temperature, despite Fe and Ba decrease with this technology. In regard to pH, data show, that skin maceration and fermentation sur marc increase K content with about 30-70% respectively, withstanding that pH also increase with a considerable 0,4-0,5 value. K content can be higher in the end product, despite to earlier higher level of tartrate formation. An attention should be driven to lower level of tartaric acid and consequently higher pH characteristic for wines produced with the application of skin maceration or fermentation sur marc.

• Analysis of the polyphenolic composition of red wines with particular respect to the resveratrol concentration

  17-22.

  M. Kállay

  D. Sárdy Nyitrainé

  Views:

  188

  In our work we have studied red wines of some vine-districts. In the centre of interest was resveratrol. We declared, there was not significant difference between varietys in polyphenol comparison. There was significant variety in anthocyanin and colour-intensity.

• The effect of bud density on the composition of colour in red wines

  63-68.

  Z. Barócsi

  I. Balogh

  M. Kállay

  G. Lukácsy

  Views:

  170

  Authors investigated the effect of fruit load on the composition of colour substances and of reservatrol in red wines of some grape varieties grown in Hungary. The content of both, anthocyanin compounds and reservatrol showed practically the same responses to fruit load and the same profile in all the varieties studied. Determination of these compounds solely is not sufficient to identify the respective grape variety.