WINETECH Technical Yearbook 2019

TABLE 1. The effect of the foliar fertilisation treatments compared to the control for 2015 and 2016 Chenin blanc and Sauvignon blanc wines at three and nine months after bottling. The effects are marked as increase, highest and statistically significant .

CB 2015 3 months

CB 2015 9 months

CB 2016 3 months

CB 2016 9 months

SB 2015 3 months

SB 2015 9 months

SB 2016 3 months

SB 2016 9 months

N *

N , N+S N*, S, N+S *

N*, S *, N+S*

N , N+S

Ethyl acetate Ethyl Butyrate Isoamyl acetate Ethyl hexanoate Ethyl lactate Ethyl caprylate Ethyl caprate Diethyl succinate

N N N N

N

N*, S *, N+S* N, S

N

N N N N N N

N *, S, N+S*

N*, S*, N+S * N*, S *, N+S*

N , S, N+S

N

N, S, N+S

N, S, N+S

Chenin blanc (2015)

Chenin blanc (2016)

Sauvignon blanc (2015)

Sauvignon blanc (2016)

N , S

N , S

N*, S *, N+S*

N

N, S, N+S

N , S N , S

↑

*significant ↑/↓

N

S, N+S

S, N+S

N, S*, N+S*

2-phenylethyl acetate

N

N

N *, S, N+S

N*, S *, N+S N, S , N+S

CB 2015 3 months

CB 2015 9 months

CB 2016 3 months

CB 2016 9 months

SB 2015 3 months N , S, N+S

SB 2015 9 months

SB 2016 3 months N, S, N+S*

SB 2016 9 months

S, N+S* N, N+S

N* , S

N , S

Propionic acid Isobutyric acid

N

N+S

N N

N*, S*, N+S*

N

N, S , N+S

N

S, N+S

N, S, N+S

Butyric acid

N, N+S

N

N+S

N , S, N+S

N*, S *, N+S* N , S*, N+S* N*, S *, N+S * N*, S *, N+S *

N N

Iso-Valeric acid

S *, N+S

S *, N+S

Valeric acid

N N

N N N

N, S , N+S

Hexanoic acid Octanoic acid Decanoic acid

Chenin blanc (2015)

Chenin blanc (2016)

Sauvignon blanc (2015)

Sauvignon blanc (2016)

N, S

N, S, N+S

N, S, N+S

*significant ↑/↓ ↑ FIGURE 1. Thiol levels (3MH and 3MHA) for the 2015 and 2016 wines as affected by the treatments and the bottle storage.

CB 2015 3 months

CB 2015 9 months N, N+S*

CB 2016 3 months

CB 2016 9 months

SB 2015 3 months N, S, N+S*

SB 2015 9 months

SB 2016 3 months N, S, N+S

SB 2016 9 months

N+S

N , N+S

N+S

N

N N N

Methanol Propanol Isobutanol

N

N+S N+S

N*, S

N , N+S N, N+S N, N+S N, N+S

N N

N, N+S

previously run. Given the complexity of the thiol chemistry in wines, at the moment we have no clear answer to why. Additionally, by looking at the overall volatile composition using Principal Component Analysis (PCA), a vintage and age effect occurred for both cultivars. Clear groupings

were observed between three and nine months of maturation, and the volatile content gradually changed during this period. Treatment effect was less evident at nine months than at three months maturation, and not a drive for the separation of samples in the multivariate data representation. In other words, the effects

S

N , S

N, S , N+S

N

N N N

N N N

N, N+S

N, S*, N+S* N , N+S

ButanoI

N

N*, S* , N+S* N, S*, N+S*

N N

Isoamyl alcohol

N+S

Hexanol

3-ethoxy-1- propanol

N

N+S

N*

N

N, N+S

N, S, N+S*

N

N

N+S

N*, S* , N+S*

N , N+S

2-phenyl ethanol