Winemaking enzymes Flashcards
What are enzymes?
Enzymes are proteins that act as biological catalysts, speeding up reactions without being consumed.
How do enzymes work?
Enzymes bind to substrates at their active sites, form enzyme-substrate complexes, and release products.
What factors affect enzyme activity?
Temperature, pH, and inhibitors like ethanol, glucose, polyphenols, and SO₂.
What is the optimum temperature for most enzymes?
Around 30-40°C, but activity drops sharply above this range.
What is the role of pectinase in winemaking?
Increases yield, reduces juice turbidity, improves settling times, and enhances lees compaction.
What are the types of pectinase?
Pectin lyase (PL), pectate lyase (PAL), pectin methyl esterase (PME), and polygalacturonase (PG).
What does cellulase do in winemaking?
Breaks down cellulose to enhance cell wall degradation, increase yield, and improve extraction of skin components.
What is the role of glycosidase/glucosidase?
Releases bound aroma/flavor compounds (e.g., terpenes, anthocyanins) from glycosides.
Why is glycosidase activity inhibited?
By glucose, alcohol, and SO₂.
What is the function of glucanase in Botrytis wines?
Degrades β-glucans to improve filterability.
How does glucanase aid yeast autolysis?
Speeds up breakdown of yeast cell walls, releasing polysaccharides for mouthfeel and stability.
What are common enzyme sources?
Aspergillus niger and Trichoderma, formulated into proprietary blends.
What are unwanted enzyme contaminants?
Anthocyanase (causes color loss) and cinnamyl esterase (produces off-flavors like vinyl phenols).
Why avoid using enzymes with bentonite?
Bentonite binds and removes proteins, including enzymes.
What is lysozyme’s role in winemaking?
Inhibits gram-positive bacteria (e.g., LAB) to delay or stop MLF; derived from egg whites.
