Grape Derived Wine Volatiles

Terpenes: NOT influenced by berry shrivelling or harvest date

Lactones, C6 compounds, norisoprenoids: small variation

www.csu.edu.au/nwgic

The National Wine and Grape Industry Centre is a research centre within Charles Sturt University in alliance with the Department of Primary Industries NSW and the NSW Wine Industry Association

Berry shrivel significantly alters Shiraz grape and wine composition

Xinyi Zhang1,2, Katja Šuklje1, Guillaume Antalick1, John W. Blackman1,2, Andrew C. Clark1,2, Leigh M. Schmidtke1,2 and Alain Deloire1

1National Wine and Grape Industry Centre, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia 2Schoole of Agricultural and Wine Science, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia

INTRODUCTION

RESULTS

MATERIALS & METHODS

A

Figure 3. A) γ-nonalactone, B) cis-3-hexenol and C) β-damascenone concentrations (µg/L) in wines. H1: first harvest date; H2: second harvest date; H3: third harvest date; S: shrivelled treatment; NS: non-shrivelled treatment.

CONCLUSION

ACKNOWLEDGEMENT The authors thank Australia’s grape growers and winemakers for their financial support through their investment body, Wine Australia and Australian Federal Government. Xinyi Zhang thanks Vinifera Euromaster program. The authors also thank Florian Imbert (Bordeaux University) for his help.

Irreversible Water Loss - Before and After Veraison

- Wide Range of Varieties

Yield Losses up to 25% Grape: Morphology & Histology

Wine Composition

Berry Shrivel

Sunburn: • poor colour development (red) • raisin formation (severe)

Late season fruit dehydration : • increased total soluble solids

Bunch stem necrosis : • necrotic rachis tissue • whole cluster or partial • predominant type of berry

shrivelling in our study

Sugar accumulation disorder : • soft, irregular-shaped berry • low fresh weight • reduced anthocyanins and sugar

accumulation

H3

Pictures:[2]

Wine H1S H1NS H2S H2NS H3S H3NS

Ethanol (% v/v) 10.2±0.2d 11.6±0.1c 11.4±0.1c 12.4±0.2b 12.8±0.04a 12.7±0.04a

Glycerol (g/L) 6.9±0.1e 8.6±0.07c 8.4±0.2d 9.0±0.01b 9.2±0.07a 9.3±0.01a

Total anthocyanins

(mg/L) 207±9e 318±6d 260±5c 353±10b 355±5b 416±20a

Total phenolics (a.u.) 22.5±0.9d 24.8±0.9c 25.1±0.1c 27.0±0.6b 29.3±0.5a 30.9±1.9a

Table 1. Basic juice and wine parameters. Univariate ANOVA was used to compare data. Means followed by different letters in a row are significant at p<0.05 (Fischer’s LSD). All stated uncertainty is the standard deviation of three replicates per treatment. H1: first harvest date; H2: second harvest date; H3: third harvest date; S: shrivelled treatment; NS: non-shrivelled treatment.

C

1.0 2.0 3.0

- Griffith (Riverina, NSW) - very warm to hot (Huglin) - own rooted, drip irrigated

VINEYARD

- H1: 17 Feb 2015 - H2: 1 Mar 2015 - H3: 6 Mar 2015

- Pilot-scale fermentation

HARVEST FERMENTATION

- TSS, pH, ammonia, NOPA - amino acid - organic acid, carbohydrates

2.2 Grape juice analysis 2.1 Grape berry sorting

H2

3.1 Wine analysis

- colour, phenolics, tannins - volatile compounds

Yeast Derived Wine Volatiles

Figure 2. High alcohol acetates concentration (µg/L) in wines. H1: first harvest date; H2: second harvest date; H3: third harvest date; S: shrivelled treatment; NS: non-shrivelled treatment.

HAA

Yeast

Grape

• increased with delayed harvest date • higher in NS-berry wines • H3: difference diminished

• metabolism modified: carbohydrates & nitrogen

• shrivel altered berry composition • similar to TSS & nitrogen in grape berry

The differences became smaller or diminished by the H3.

Ethyl Esters of Branched Acids (EEBAs): • NOT influenced by shrivel or harvest date

Ethyl Esters of Fatty Acids (EEFAs): • small variation

Higher Alcohol Acetates (HAAs): • strongly influenced by shrivel & maturity

• higher in S-berry wines • γ-nonalactone: marker of grape berry shrivelling, prune aroma • cis-3-hexenol: decreased with ripening, fresh & green aromas • β-damascenone: prune aroma

B

‘Harvest date’ and ‘berry shrivel’ influenced grape and wine chemical composition significantly and independently.

• delayed grape ripening: reduced grape fresh mass and sugar (at H1 & H2) and nitrogen contents

in grape juice; • reduced the content of anthocyanins, and ethanol (at H1 & H2) and ester concentrations in

wines; • produced small or no variation on lactones, C6 compounds, norisoprenoids and terpenes

concentrations in wines; • results in differences between S and NS became less pronounced at H3; • different types of shrivelling may have different effects on grape and wine composition.

REFERENCE [1] Šuklje & Zhang et al. (2016). Journal of Agricultural and Food Chemistry, 64(4):870-880. [2] Krasnow et al. (2010). California Agriculture, 64:155–159. [3] Deloire, A. (2013). 15th Australian Wine Industry Technical Conference. 47-50.

Figure 1. A) Berry fresh weight (g). B) Juice FAN (free amino nitrogen) (mg N/L). C) Juice TSS (total soluble solids) (°Brix). D) Grape sugar accumulation (mg/berry). H1: first harvest date; H2: second harvest date; H3: third harvest date; S: shrivelled treatment; NS: non-shrivelled treatment.

A

• S: incremental increase of solutes from H1 to H3

• NS: increased from H1 to H2 only

B

D

CONSEQUENCES OF SHRIVELLING

Grape & Juice

significantly reduced berry fresh mass lower free amino nitrogen (FAN) lower total soluble solids (TSS)

Wine

lower ethanol & glycerol: similar to sugar variation in grape berry lower total anthocyanins lower total phenolics

C

[3]

Berry shrivelling:

H1