Document details

Quantificação de azoto facilmente assimilável de uvas brancas e tintas da Tapada da Ajuda em dois anos consecutivos (2013 e 2014). Validação e comparação da titulação formol e FT-MIR

Author(s): Veiga, Cláudio Alexandre Assis da

Date: 2014

Persistent ID: http://hdl.handle.net/10400.5/8225

Origin: Repositório da UTL

Subject(s): vineyard; grape must; YAN; formaldehyde; FTIR and formol titration


Description

The purpose of this work is to quantify the yeast assimilable nitrogen (YAN), in Tapada grapes whether by the formol titration (TF) or the Fourier transform infrared spectroscopy (FTIR). To the TF we have used model solutions and natural grapes and the recovery rates of YAN were between 89-96% for the arginine and 77-90% for the ammonium. The repeatability and reproducibility correspond to ± 4,43 (mg N/L) and ± 14,95 (mg N/L) respectively. Then the YAN in the Tapada grapes of the years 2013 and 2014 was quantified. Being that only the Arinto variety in 2013 had values near 140 mg N/L, as accepted in the bibliography as a great value. Despite of a small increase of the YAN in some of the vine varieties of the year 2014, the other vine varieties are under those values when related to the two years studied. TF was used as a method of reference for the recalibration of FTIR. 117 musts (ISA musts of 2013 and other sites from 2010) were used for the recalibration of FT-MIR. It was not possible to determine the YAN using the FTIR, due to little relationship between the quantification values of YAN in TF and FTIR.

Mestrado em Viticultura e Enologia - Instituto Superior de Agronomia / Faculdade de Ciências. Universidade do Porto

Document Type Master thesis
Language Portuguese
Advisor(s) Silva, Jorge Manuel Ricardo
Contributor(s) Veiga, Cláudio Alexandre Assis da
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