Transcript Impact of Nutrients on Saccharomyces Aroma Compounds

Impact of Nutrients on
Saccharomyces Aroma
Compounds
Linda F. Bisson
Department of Viticulture and Enology
University of California, Davis
Yeast Nutrition
Macronutrients: Building blocks needed
for new cell material
Micronutrients: Catalysts needed to
facilitate biochemical reactions
Macronutrients
Carbon/Energy Sources: glucose,
fructose, sucrose
Nitrogen Sources: amino acids,
ammonia, nucleotide bases, peptides
Phosphate Sources: inorganic
phosphate, organic phosphate
compounds
Sulfur Sources: inorganic sulfate,
organic sulfur compounds
Micronutrients
Minerals and Trace Elements: Mg,
Ca, Mn, K, Zn, Fe, Cu
Vitamins: biotin is the only required
vitamin, but others are stimulatory
Nutrients Are Required For:
Creation of new cells
Maintenance of metabolism
Adaptation to new environments
Stress tolerance
Nutritional Requirements of
Different Phases of Fermentation
Growth Phase: Building blocks and
catalysts
Stationary Phase: Survival factors
Yeast Nutritional Phases
stationary
death
Cell #
log
Brix
lag
Time
Survival Factors
Oxygen
Fatty Acids
Sterols
Nutritional Factors
Nutrition and Aroma
Allow fed species to proliferate and
dominate
Affects persistence in environment and
prevention of spoilage
Directs end product formation
Affects enzymatic activities
Macronutrients and Aroma
Sugars: give rise to ethanol, organic acids,
fatty acids
Nitrogen compounds: give rise to esters,
fusel alcohols and aldehydes
Sulfur compounds: give rise to S-volatiles
Micronutrients and Aroma
Impacts enzymatic portfolio
Limitation can impact cell growth and
metabolism
Can be degraded if in excess to aromatic
compounds
Nutrient Additions Tasting
Glass 1: No addition
Glass 2: Phosphate titers
Glass 3: Bioferm Equilibre
Glass 4: Bioferm Xtreme: one addition
Glass 5: Bioferm Xtreme: split addition
Glass 6: Nutrex 370
The Nutrients
Nutrients
Rate of
Addition
(lb /1000
gal)
Diammonium
Phosphate
(DAP)
Thiamine
0.5
+
+
1.0
+
+
+
1.5
+
+
+
Amino
Acids
Yeast Hulls
No Addition
Scott Lab
Phosphate
Titers
Bioferm®
Equilibre
Bioferm®
Xtreme
+
Nutrex 370
2.0
+
Composition of Chardonnay Juice
ºBrix
25.25
pH
3.66
TA (g/L)
4.98
NOPA
(mg/L)
56
Ammonia YAN
(mg/L)
(mg/L)
132
188
Yeast Strain
Lalvin M2®