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• Effect of certain bentonite products on the temporal variation of elemental content in white wine

  15-21.

  N. Rakonczás

  Z. Kállai

  G. Antal

  B. Kovács

  I. J. Holb

  Views:

  148

  The 'terroir' character of wines can be shaped with certain technological elements such as bentonite fining. Bentonite is an agent used for the removal of thermolabile proteins in wines. However, during fining, the quantity of certain wine components can change, including the elemental composition of the wine. According to the recommendations of bentonite suppliers, wines should be racked off the bentonite fining sediment within 2-3 weeks. However, in winemaking practice, wines can remain on bentonite fining sediment for up to 1-4 months. One reason for this is that racking wines off the sediment has a negative impact on wine quality. Thus, it is a question of how much the later or earlier racking time can alter the elemental content of the wine. Our study aimed to examine the elemental content of wines treated with three different bentonite products sampled from over the bentonite fining sediment at various time points. Our investigation was conducted with the 2019 vintage white wine of the University of Debrecen. Fining was performed with three bentonite products: Nucleobent, BW200, and Granubent Poretec. The sampling schedule following fining was: 0 days - unfined control, 7th, 14th, 27th, 56th, and 85th days. The macro-, meso-, and microelement contents (P, K, Ca, Mg, S, Al, Na, B, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Cd, Ba, and Pb) of the wines were determined using ICP OES and ICP MS devices. Our results showed significant changes in the Al, Na, Cr, Fe, Co, Ni, Sr, Ba, Cu, and Pb contents of the wines depending on the sampling time. It is noteworthy that all three bentonite products increased the Al and Pb contents of the wines. For Fe, dynamic increases were observed over time with the BW200 product, reaching the threshold value of susceptibility to brakeage. However, from a winemaking technology perspective, it was favorable for the Cu content of the wines to decrease with both earlier and later racking times, for all bentonite products examined. Based on the elemental analyzes of the white wines studied, it can be concluded that racking of wines should be timed according to the recommendations of suppliers.

• The effect of soil mixtures of different consistence and phosphorus content in tray transplant-growing by lettuce

  71-76.

  K. Tóth

  N. Kappel

  K. Slezák

  B. Irinyi

  Views:

  400

  The transplant-growing with root balls gets more and more popular and time to time the only method even in high-quality lettuce transplant-growing. To work out the technology of transplant-growing in trays it was needed to define the accurate physical and chemical consistency of applied soils.

  The transplant production in trays could become a good method in field-grown lettuce technologies. The production of transplants of good quality with this technology could be realised only by accurate soil mixtures.

  The matter of transplant-growing substrates could be a low-moor turf. Its qualities could be positively influenced by adding minerals like bentonite in amount of 5 (or 10) V%.

  To ensure enough phosphorus for the demands of transplants we have to add more fertilisers. The best results by lettuce we got by adding 4 kg/m³ superphosphate to the soil mixture.