Experiments for developing selective clarification techniques: Sterol and fatty acid loss from

• Autores: C. Delfini, C. Cocito
• Localización: Journal of wine research, ISSN 0957-1264, Vol. 8, Nº 3, 1997, págs. 187-198
• Idioma: inglés
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• Resumen

  • Differential removal of long‐chain fatty acids and sterols from must was investigated using different clarification techniques, combinations of three clarification agents and different flotation speeds. The results obtained both in laboratory and cellar experiments proved that the removal of palmitic acid, oleic acid, linoleic acid and linolenic acid as well as free squalene, stigmastanol and ß‐sitosterol from must varies depending on the clarification technique, quantity of clarification adjuvants and flotation speed. Cold static clarification (débourbage) obtained in laboratory experiments with an addition of 10 gl‐1 of gelatine and 40 g l‐1 of bentonite caused the strongest loss of fatty acids and sterols compared to cold débourbage without clarifier agents and to flotation. Flotation appeared to be a continuous clarification technique for grape musts that could allow the regulation of the removal efficacy of some important grape must compounds. In fact, in cellar experiments, fast flotation or flotation performed with low amounts of clarifiers had lower removal effects than cold débourbage on free fatty acids and free ß‐sitosterol and stigmastanol. Thus, selective clarification for some important oenological classes of compounds, aimed at a definite technological result, seems to be a reachable goal and is worth researching further.