Chapter 4
Enzymes in Winemaking
Maurizio Ugliano
Contents
4.1 Introduction........................ ........................................ 103
4.2 Polyphenol Oxydases................ ........................................ 104
4.3 Lipoxygenase and Hydroxyperoxide Cleaving Enzymes..................... ...... 106
4.4 WineStabilizationEnzymes .................................................. 107
4.4.1 Proteases............................................................. 107
4.4.2 Lysozyme............................................................ 107
4.5 Pectolitic Enzymes.................. ........................................ 108
4.6 AromaEnhancingEnzymes .................................................. 110
4.6.1 Glycosidases ......................................................... 110
4.6.2 Cysteine-S-Conjugate -Lyases.......................................... 118
4.6.3 Esterases............................................................. 119
4.7 Conclusion................................................................. 120
References................................................................. 121
4.1 Introduction
It is generally accepted that grape composition plays a primary role in determining
the final quality of wine. However, many of the sensory characteristics that are
normally used to assess the quality of a wine, including those that are considered
typical of the grape variety, cannot be detected in the grapes. They develop in fact,
in large part, through a complex array of biochemical reactions that take place
during the winemaking process. The majority of these reactions are catalyzed by
different enzymes coming form various sources, particularly grapes and microor-
ganisms. Many sensorially-active constituents of wine are affected, at different
stages of winemaking, by biochemical transformations that are catalyzed by specific
enzymes. For example, enzymes are involved in the oxidation of grape phenolics, in
the formation of volatile compounds during pre-fermentative operations, and in the
transformation of odorless precursors into odor-active compounds during alcoholic
M. Ugliano (B)
The Australian Wine Research Institute, PO Box197 Glen Osmond (Adelaide), SA 5064, Australia
e-mail: [email protected]
M.V. Moreno-Arribas, M.C. Polo (eds.),Wine Chemistry and Biochemistry,
DOI 10.1007/978-0-387-74118-55,©CSpringer Science+Business Media, LLC 2009
103