Details

Autor(en) / Beteiligte

• Neves, Nuno Miguel Nunes

Titel

Oenological Performance Evaluation of Yeast Strains : Implementation of an Analytical Method for Biogenic Amines in Wines by HPLC-Fluorescence

Ort / Verlag

ProQuest Dissertations & Theses

Erscheinungsjahr

2012

Link zum Volltext

• ProQuest

Quelle

ProQuest Dissertations & Theses A&I

Beschreibungen/Notizen

• Biogenic amines are low molecular weight organic compounds derived from amino acids that may be formed throughout the winemaking process. Their presence in wine is undesirable due to the hazardous effects they may cause on human health.This Thesis presents the implementation of a method for analysis of levels of five of the main biogenic amines (histamine, tyramine, phenylethylamine, putrescine and cadaverine) in wine. In order to accomplish that, the method makes use of an online pre-column derivatization of the samples with ortho-phthalaldehyde (OPA). An elution gradient of 50 minutes allows the separation of the amines for consequent quantification. Regarding the limits of detection and quantification, 1.5 ± 0.9 mg/L and 5 ± 3 mg/L, respectively, were obtained while achieving an average recovery percentage and precision (CV%) of 85 ± 15% and 9 ± 4%, respectively.The developed method was applied to 26 wines.Samples from malolactic fermentation trials revealed that this phase has a detrimental effect on the contents of biogenic amines registering increases in histamine, putrescine and specially tyramine (from not detected to 29 ± 16 mg/L) when compared to wine samples in which malolactic fermentation did not take place. However, the results are not consistent with the values found for other red wines that also experienced malolactic fermentation. Therefore, other features are taking part in biogenic amine formation.For the white wines tested the variety effect seems to override strain specific production of biogenic amines. Absolute values of biogenic amines in these wines vary from non detected in most cases for tyramine to a maximum of 3.9 mg/L found for histamine.Another part of the work consisted on making an evaluation of the oenological performance of five yeast strains previously selected from other FERMDIF projects (386, 496, 666, 765 and QA23) over three white grape varieties (Loureiro, Viosinho and Encruzado).The strain with best performance regardless of the variety was strain 666. For varieties Viosinho and Encruzado the worst strain was strain 765 while for Loureiro strain 496 has given the worst results. Biogenic amine production evaluated in these combinations of strain and variety resulted in the lowest values attributed to strain 765, average for strains 666 and QA23 and the highest for strains 386 and 496. Viosinho was the variety for which overall biogenic amine production was lower.