Wine Aroma Stability and Preservation Ca Carie ien Co Coetz tzee - PowerPoint PPT Presentation

Wine Aroma Stability and Preservation Ca Carie ien Co Coetz tzee May 2017

Wine Aroma Stability and Preservation • Premature aging related to oxidation • Loss of freshness • Loss of colour • Loss of complexity • Development of aging/oxidation characters Image source: Wine Folly

(Illustration by the AWRI and presented at the AWITC workshop by Maurizio Ugliano, 2010)

Most compounds are formed in excess during fermentation • Not in equilibrium • It will take some to equilibrate/stabilize Acid id hydrolysis is during aging • Hydrolysis is favoured by lower pH and higher temperatures Decline contributes to the loss of freshness and fruitiness in wines during aging (Illustration by the AWRI and presented at the AWITC workshop by Maurizio Ugliano, 2010)

Exposure to oxygen • Chain of Oxidation reactions • Decrease in aroma compounds • Increase in oxidation aroma • Oxidation is favoured by higher pH and higher temperatures Oxidation contributes to the loss of freshness and fruitiness in wines during aging (Illustration by the AWRI and presented at the AWITC workshop by Maurizio Ugliano, 2010)

(Illustration by the AWRI and presented at the AWITC workshop by Maurizio Ugliano, 2010)

Development of oxidation colour Loss of pleasant aroma Formation of oxidation aroma (Ugliano, 2013)

Limit / remove metals Trap radicals and oxidation agents Limit oxygen exposure Development of oxidation colour Loss of pleasant aroma Formation of oxidation aroma (Ugliano, 2013)

Con ontrol Ox Ox A B C T0 T0 A B C A B C T1 T1 A B C A B C T2 T2 A B C T3 T3 A B C A B C T4 T4 A B C A B C T5 T5 A B C Coetzee et al., 2016 Journal of Agriculture and Food Chemistry

Ox Ox Con ontrol A B C T0 T0 Oxidation over time Aging over time A B C A B C T1 T1 A B C A B C T2 T2 A B C T3 T3 A B C A B C T4 T4 A B C A B C T5 T5 A B C Coetzee et al., 2016 Journal of Agriculture and Food Chemistry

Control Ox A B C T0 0 mg/L 6.59 e mg/L A B C 0 mg/L A B C T1 11.39 d mg/L A B C 0 mg/L A B C T2 16.99 c mg/L 0 mg/L A B C T3 A B C 0 mg/L A B C 22.18 b mg/L T4 A B C 29.99 a mg/L 0 mg/L A B C T5 A B C Coetzee et al., 2016 Journal of Agriculture and Food Chemistry

Image source: Wine Folly

Image source: Wine Folly

Treatment Oxygen (mg/L) 4MMP concentration (ng/L) 10 15 20 25 30 35 40 45 0 5 0 T0 Control T0 Control a C 0 T1 Control T1 Control b cde 0 T2 Control T2 Control 0 T3 Control T3 Control c 0 T4 Control T4 Control f 4MMP Treatment 0 T5 Control T5 Control fd e T1 Ox T1 Ox 6.59 b d T2 Ox 11.93 T2 Ox cd c T3 Ox T3 Ox 16.99 fe b T4 Ox 22.18 T4 Ox f a T5 Ox 29.99 T5 Ox f

Treatment 3MHA concentration (ng/L) Oxygen (mg/L) 100 110 120 10 20 30 40 50 60 70 80 90 0 T0 Control 0 T0 Control a A T1 Control 0 T1 Control b T2 Control bc 0 T2 Control T3 Control 0 T3 Control c T4 Control 0 T4 Control c Treatment 3MHA T5 Control c 0 T5 Control T1 Ox bc e T1 Ox 6.59 T2 Ox d d T2 Ox 11.93 T3 Ox de c T3 Ox 16.99 T4 Ox b f T4 Ox 22.18 T5 Ox fe a T5 Ox 29.99 l

Treatment 3MH concentration (ng/L) Oxygen (mg/L) 1000 100 200 300 400 500 600 700 800 900 0 T0 Control T0 Control c B 0 T1 Control T1 Control c 0 T2 Control T2 Control a 0 T3 Control T3 Control a 0 T4 Control T4 Control a Treatment 0 T5 Control T5 Control b 3MH e T1 Ox T1 Ox d 6.59 d T2 Ox T2 Ox e 11.93 c T3 Ox T3 Ox f 16.99 T4 Ox b T4 Ox f 22.18 T5 Ox a g T5 Ox 29.99

3M 3MHA Treatment 3MH concentration (ng/L) Oxygen (mg/L) 1000 100 200 300 400 500 600 700 800 900 0 T0 Control T0 Control c B 0 T1 Control T1 Control c 0 T2 Control T2 Control a 0 T3 Control T3 Control a 0 T4 Control T4 Control a Treatment 0 T5 Control T5 Control b 3MH e T1 Ox T1 Ox d 6.59 3M 3MH d T2 Ox T2 Ox e 11.93 c T3 Ox T3 Ox f 16.99 T4 Ox b T4 Ox f 22.18 T5 Ox a g T5 Ox 29.99 ace acetic acid acid

No decrease was seen for 3MH! 3MHA Kilmartin presentation

Treatment Oxygen Isoamyl Acetate (mg/L) (mg/L) 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 T0 Control 0 T0 Control a T1 Control 0 T1 Control b A 0 T2 Control T2 Control Isoamyl acetate c T3 Control 0 T3 Control cd 0 T4 Control T4 Control ed Treatment Treatment T5 Control efd 0 T5 Control Oxygen 2-Phenylethyl acetate (mg/L) (mg/L) 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 e T1 Ox T1 Ox b 6.59 d T0 Control T2 Ox T2 Ox ed 0 T0 Control a 11.93 c T1 Control T3 Ox 0 T1 Control T3 Ox ef b 16.99 C b T2 Control bc T4 Ox T4 Ox 0 T2 Control ef 22.18 a T3 Control T5 Ox 0 T3 Control dc T5 Ox 29.99 f dec 0 T4 Control T4 Control Treatment T5 Control 0 T5 Control de Treatment Hexyl Acetate (mg/L) Oxygen (mg/L) e T1 Ox T1 Ox b 6.59 0.76 0.78 0.80 0.82 0.84 0.86 0.88 0.90 0.92 0.94 d dec T2 Ox T2 Ox 11.93 0 T0 Control T0 Control a c T3 Ox T3 Ox de 16.99 0 T1 Control T1 Control b B b T4 Ox T4 Ox de 22.18 0 T2 Control T2 Control c a T5 Ox T5 Ox 29.99 e 0 T3 Control T3 Control cd Hexyl acetate T4 Control ed 2-Phenylethyl acetate 0 T4 Control Treatment efd T5 Control 0 T5 Control e T1 Ox T1 Ox b 6.59 d T2 Ox ed T2 Ox 11.93 T3 Ox c ef T3 Ox 16.99 T4 Ox b ef T4 Ox 22.18 T5 Ox a f T5 Ox 29.99

Image source: Wine Folly

• Methoxypyrazines not sensitive to aging/oxidation • Even hyperoxidation of a wine using H 2 O 2 did not lead to decreases • Sensitive to photodegradation

• Change due to oxidation and/or transformation Transformation of terpenes Monoterpene alcohol Monoterpene oxide Change in aroma and change in perception threshold Image source: Wine Folly

Passion Fruit Fresh Green Potato Bag Lemon Guava T0 Control T0 Control Green Apple Sherry Pineapple T5 Ox T5 Ox Grapefruit T1 Ox T1 Ox T4 Ox T4 Ox PC2(6.3) T4 Control T4 Control T2 Control T2 Control T3 Control T3 Control T1 Control T1 Control T5 Control T5 Control T2 Ox T2 Ox T3 Ox T3 Ox Raisins Syrup Honey Cooked Green Dried fruit Banana Yellow Apple scores PC1(90.5) loadings

Red wine has a different aging dynamic Limited amounts of oxygen and aging improves wine aroma

Glycoconjugated precursors may be acid hydrolized during wine aging and storage Increase in β -damascenone β -Damascenone may be oxidised into odourless forms Decrease in β -damascenone Image source: Wine Folly

Rotundone concentration reported to be stable under proper storage conditions • Unlikely to change drastically during wine aging Image source: Wine Folly

Image source: Wine Folly

(Illustration by the AWRI and presented at the AWITC workshop by Maurizio Ugliano, 2010)

• Concentration • Temperature • pH (Illustration by the AWRI and presented at the AWITC workshop by Maurizio Ugliano, 2010)

• Limit O 2 exposure • Temperature • pH • Antioxidants • SO 2 • Glutathione • Ascorbic acid • Phenolic compounds • Remove metals (Illustration by the AWRI and presented at the AWITC workshop by Maurizio Ugliano, 2010)

BALANCE

Wine Aroma Stability and Preservation Ca Carie ien Co Coetz tzee May 2017