Understanding the Effects of Wine Matrix Compounds on the Perception of Aromatic Wine Faults

185 Pages·2016·1.96 MB·English

Understanding the Effects of Wine Matrix Compounds on the Perception of
Aromatic Wine Faults
By
Daniel Kim

A thesis
presented to
The University of Guelph

In partial fulfilment of requirements
for the degree of
Doctor of Philosophy
in
Food Science

Guelph, Ontario, Canada
© Daniel Kim, December, 2016
i
ABSTRACT

UNDERSTANDING THE EFFECTS OF WINE MATRIX COMPOUNDS ON THE
PERCEPTION OF AROMATIC WINE FAULTS

Daniel Kim Advisor:
University of Guelph, 2016 Dr. Massimo Marcone

Understanding the impact of aromatic wine faults on consumer acceptability is extremely
important to the wine industry. The negative impact of having a faulty wine in the retail space
can have a detrimental effect on both the winery and retailer. Literature has shown that the wine
matrix components can have an impact on the perception of aromatic flavour compounds. If
wine matrix components have the ability to reduce the perception of the faults, this can increase
the wine’s acceptability for sale. In this research, the influence of three wine matrix components,
ethanol, tannic acid, and tartaric acid on seven compounds responsible for wine faults,
acetaldehyde (oxidation), 4-ethylphenol and 4-ethyguaiacol (Brettanomyces taint), 2,4,6-
trichloroanisole (cork taint), 2-isoproply-3-methoxypyrazine (multicoloured Asian lady beetle
taint), and acetic acid and ethyl acetate (volatile acidity) were studied using sensory and
chemical methods to develop an algorithm to correlate chemical analyses with wine saleability.
Sensory analysis, using a panel of experienced wine tasters, demonstrated that increasing
the ethanol concentration from 5% alc./vol. to 17% alc./vol. in water significantly decreased the
panel’s ability to detect the wine faults aromatically, while the increase of either tannic acid
(0.05g/L to 5g/L) or tartaric acid (2.5mg/L to 200mg/L) concentration in a water: 5% alc./vol.
solution had no statistically significant impact on the detection of the faults. Chemical analysis
using Static Headspace Gas Chromatography Mass Spectrometry (SH-GC-MS) supported the
sensory analysis findings, except in the case of acetic acid, where none of the wine matrix
components studied had any significant influence on its detection.
The influence of ethanol concentration on the perception of aromatic wine faults in an
Ontario Riesling at 9.5% alc./vol. and another adjusted to 13% alc./vol. on the wine’s
ii
acceptability for sale was studied using experienced wine tasters. Results had shown that
modifying the ethanol concentration did not have a statistically significant effect on changing the
wine’s acceptability for sale when the faults are present. As an algorithm to correlate chemical
analyses to wine saleability could not be determined, sensory evaluation is required as it provides
a greater assurance in determining wine saleability.

iii
ACKNOWLEDGEMENTS
I would like to thank the LCBO for supporting this research project. To my advisor Dr.
Massimo Marcone, and advisory committee members, Dr. George Soleas, Dr. Chris Findlay, and
Dr. Paul McNicholas, I am grateful for their patience, guidance and support throughout this
research. Dr. Sunan Wang, thank you for your expertise and help from the very beginning.
To my wife, Kris, my family and friends, thank you for all your prayers, support and
encouragement.
I would like to also thank Dr. Tony Cullen for his friendship and guidance throughout
the study. You will be greatly missed.
Finally, I praise and thank God for allowing me to meet all these great people who have
supported me throughout the course of this study.

iv
TABLE OF CONTENTS
CHAPTER 1 - UNDERSTANDING THE EFFECTS OF WINE FAULTS IN THE
RETAIL SPACE – LITERATURE REVIEW ...................................................................... 1
ABSTRACT .................................................................................................................................................. 1
1. INTRODUCTION ..................................................................................................................................... 1
Importance of aromatic faults .................................................................................................... 2
The Effects of Several Compounds to Make a Characteristic Wine Fault ................................ 3
Cork Taint .................................................................................................................................. 4
Pyrazines .................................................................................................................................... 4
Brettanomyces Taint ................................................................................................................... 5
Volatile Acidity .......................................................................................................................... 6
Oxidation Through the Development of Acetaldehyde ............................................................. 6
The Influence of Wine Matrix on Aromatic Faults .................................................................... 7
Ethanol ....................................................................................................................................... 7
Tannins ....................................................................................................................................... 8
Organic Acids and salts .............................................................................................................. 9
Sensory Methods – Discrimination Testing ............................................................................... 9
A Not-A .................................................................................................................................... 10
Triangle Test ............................................................................................................................ 11
3-Alternate Forced Choice Test (3-AFC) ................................................................................ 12
Tetrad Test ............................................................................................................................... 12
Analysis of Sensory Tests ........................................................................................................ 13
Correlation of Chemical Analysis to Sensory Data ................................................................. 17
Liquid-Liquid Extraction ......................................................................................................... 18
Solid-Phase Extraction ............................................................................................................. 19
Headspace Extraction ............................................................................................................... 20
v
2. CONCLUSION ....................................................................................................................................... 23
3. RESEARCH OBJECTIVES........................................................................................................................ 24
4. HYPOTHESIS ........................................................................................................................................ 25
5. METHODOLOGY .................................................................................................................................. 25
CHAPTER 2 - AN ASSESSMENT ON THE SUITABILITY OF THE STATIC
HEADSPACE METHODOLOGY ON THE ANALYSIS OF AROMATIC WINE
FAULTS .................................................................................................................................. 27
ABSTRACT ................................................................................................................................................ 27
1. INTRODUCTION ................................................................................................................................... 27
Choice of Column .................................................................................................................... 28
2. MATERIALS AND METHODS ................................................................................................................ 29
Chemicals and Reagents .......................................................................................................... 29
Optimization of Static Headspace Gas Chromatography Mass Spectrometry ......................... 31
Sample Preparation .................................................................................................................. 33
Statistical Analysis ................................................................................................................... 34
3. RESULTS AND DISCUSSIONS ................................................................................................................ 35
4. CONCLUSIONS ..................................................................................................................................... 41
CHAPTER 3 - DETECTION THRESHOLD DETERMINATION OF COMMON
AROMATIC WINE FAULTS BY EXPERIENCED WINE TASTERS .......................... 43
ABSTRACT ................................................................................................................................................ 43
1. INTRODUCTION ................................................................................................................................... 43
2. MATERIALS AND METHODS ................................................................................................................ 45
Chemicals and Reagents .......................................................................................................... 45
Sensory Analysis ...................................................................................................................... 47
Statistical Analysis ................................................................................................................... 48
3. RESULTS AND DISCUSSIONS ................................................................................................................ 48
4. CONCLUSIONS ..................................................................................................................................... 50
5. ACKNOWLEDGEMENTS ....................................................................................................................... 50
vi
CHAPTER 4 - THE EFFECTS OF THE WINE MATRIX ON THE VOLATILITY
AND PERCEPTION OF WINE FAULTS .......................................................................... 51
ABSTRACT ................................................................................................................................................ 51
1. INTRODUCTION ................................................................................................................................... 51
2. MATERIALS AND METHODS ................................................................................................................ 55
Chemicals and Reagents .......................................................................................................... 55
Gas Chromatographic Analysis ................................................................................................ 56
Sensory Analysis ...................................................................................................................... 58
Statistical Analysis ................................................................................................................... 60
3. RESULTS AND DISCUSSIONS ................................................................................................................ 61
4. CONCLUSIONS ..................................................................................................................................... 68
5. ACKNOWLEDGEMENTS ....................................................................................................................... 68
CHAPTER 5 - THE DETERMINATION OF THE DETECTION THRESHOLD AND
REJECTION THRESHOLD OF AROMATIC WINE FAULTS IN AN ONTARIO
RIESLING ............................................................................................................................... 69
ABSTRACT ................................................................................................................................................ 69
1. INTRODUCTION ................................................................................................................................... 69
2. MATERIALS AND METHODS ................................................................................................................ 71
Sensory Analysis ...................................................................................................................... 71
Statistical Analysis ................................................................................................................... 73
3. RESULTS AND DISCUSSIONS ................................................................................................................ 73
Acetaldehyde (Oxidation) ........................................................................................................ 73
Acetic acid (Volatile Acidity) .................................................................................................. 77
Ethyl Acetate (Volatile Acidity) .............................................................................................. 81
2-Isopropyl-3-methoxypyrazine (MALB Taint) ...................................................................... 85
2,4,6-Trichloroanisole (Cork Taint) ......................................................................................... 89
4-Ethylphenol (Brettanomyces Taint) ...................................................................................... 93
4-Ethylguaiacol (Brettanomyces Taint) ................................................................................... 98
vii
Detection Threshold and Rejection Threshold ....................................................................... 102
4. CONCLUSION ..................................................................................................................................... 103
5. ACKNOWLEDGMENTS ....................................................................................................................... 104
CHAPTER 6 -THE EFFECTS OF ETHANOL ON THE PERCEPTION OF
AROMATIC WINE FAULTS AND SALEABILITY OF AN ONTARIO RIESLING 105
ABSTRACT .............................................................................................................................................. 105
1. INTRODUCTION ................................................................................................................................. 105
2. METHODS AND MATERIALS .............................................................................................................. 107
Chemicals and Reagents ........................................................................................................ 107
Wine Samples ......................................................................................................................... 107
Sensory Analysis .................................................................................................................... 108
Statistical Analysis ................................................................................................................. 110
3. RESULTS AND DISCUSSION ................................................................................................................ 111
Base Wine .............................................................................................................................. 111
4-Ethylphenol (Brettanomyces Taint) .................................................................................... 117
2-Isopropyl-3-methoxypyrazine (MALB Taint) .................................................................... 123
Ethyl Acetate (Volatile Acidity) ............................................................................................ 129
2,4,6-Trichloroanisole (Cork Taint) ....................................................................................... 135
Influence of Ethanol ................................................................................. on the Rejection Threshold
................................................................................................................................................ 141
4. CONCLUSION ..................................................................................................................................... 142
5. ACKNOWLEDGEMENTS ..................................................................................................................... 143
CHAPTER 7 - CONCLUSIONS AND FUTURE RESEARCH ...................................... 144
1. CONCLUSIONS ................................................................................................................................... 144
2. FUTURE RESEARCH ............................................................................................................................ 145
REFERENCES ....................................................................................................................... 147

viii
LIST OF TABLES
CHAPTER 1 - UNDERSTANDING THE EFFECTS OF WINE FAULTS IN THE
RETAIL SPACE – LITERATURE REVIEW ...................................................................... 1
Table 1.1. Possible combinations that can be used in a duo-trio test ....................................... 10
Table 1.2. The possible combinations that can be used in a triangle test. ............................... 11
Table 1.3. The possible combinations that can be used in a 3-AFC test. ................................. 12
Table 1.4. The possible combinations that can be used in a Tetrad test. ................................. 13
Table 1.5. A list of references showing different types analytical methods for the extraction
and analysis of different aromatic compounds that can be found in wines. ............................ 22
CHAPTER 2 - AN ASSESSMENT ON THE SUITABILITY OF THE STATIC
HEADSPACE METHODOLOGY ON THE ANALYSIS OF AROMATIC WINE
FAULTS .................................................................................................................................. 27
Table 2.1. Information on the chemicals used in studying the effects of the wine matrix on the
volatility and perception of wine faults. ................................................................................... 30
Table 2.2. Headspace GC-MSD conditions and parameters to be optimized. ......................... 32
Table 2.3. List of aromatic faults with the correlating m/z ratio. ............................................ 33
Table 2.4. The concentration of the aromatic faults to be spiked in a 5% alc./vol.
ethanol/water solution. ............................................................................................................. 34
Table 3.2. Static Headspace GC-MSD conditions used to for the analysis of aromatic wine
faults. ........................................................................................................................................ 41
CHAPTER 3 - DETECTION THRESHOLD DETERMINATION OF COMMON
AROMATIC WINE FAULTS BY EXPERIENCED WINE TASTERS .......................... 43
Table 2.1. Information on the chemicals used in studying the effects of the wine matrix on the
volatility and perception of wine faults. ................................................................................... 46
Table 2.2. Concentrations of the wine aromatic defects used to determine the best estimated
threshold in a 5% alc./vol. ethanol in water solution. .............................................................. 47
ix
Table 3.1. D-prime results on the concentration levels of the aromatic wine faults when
evaluated at room temperature in 5% alc./vol. ethanol:water solution. ................................... 49
Table 3.2. The best estimation threshold (BET) concentrations of aromatic wine when
evaluated at room temperature in 5% alc./vol solution. ........................................................... 50
CHAPTER 4 - THE EFFECTS OF THE WINE MATRIX ON THE VOLATILITY
AND PERCEPTION OF WINE FAULTS .......................................................................... 51
Table 2.1. Information on the chemicals used in studying the effects of the wine matrix on the
volatility and perception of wine faults. ................................................................................... 55
Table 2.2. Concentration of the aromatic wine faults used to determine the effects of wine
matrix components (i.e. ethanol, tartaric acid, tannic acid) on the volatility of aromatic wine
faults in synthetic binary and ternary solutions using static headspace gas chromatography. 56
Table 2.3. Concentration of ethanol, tannic acid, and tartaric acid used to determine their
effects on the volatility of aromatic wine faults using static headspace gas chromatography. 57
Table 2.4. Headspace GC-MSD conditions used in this study. ............................................... 58
Table 2.5. Concentration of the aromatic wine faults used to determine the effects of wine
matrix components (i.e. ethanol, tartaric acid, tannic acid) on the perception of aromatic wine
faults in synthetic binary and ternary solutions using experienced wine tasters. ..................... 59
Table 2.6. Concentration of ethanol, tannic acid, and tartaric acid used to determine their
effects on the perception of aromatic wine faults using experienced wine tasters. ................. 60
Table. 3.1 ANOVA results showing the effects of the wine matrix components (ethanol,
tannic acid, and tartaric acid) on the partitioning of the aromatic wine faults when analyzed
on SH-GC-MS. ......................................................................................................................... 62
Table 3.2. Solubility and boiling point data of acetaldehyde, acetic acid, and ethyl acetate
retrieved from the PubChem Substance and Compound database, NCBI, USA
(https://pubchem.ncbi.nlm.nih.gov/). ....................................................................................... 65
Table 3.3. D-prime results showing the effects of the wine matrix components (ethanol,
tannic acid, and tartaric acid) on the perception of the aromatic wine faults. .......................... 67
x