Official Journal of the Japan Wood Research Society
Table 2 In vitro model of ellagitannins chemistry during duraminisation process: influence of oxidation (1 vs. 2)1; influence of association of oxidised ellagitannins and polysaccharides (a vs. b)2 (initial extract from acetone/water (7/3, v/v) extraction of Q. robur outer heartwood)
From: Origin and characterisation of the extractable colour of oak heartwood used for ageing spirits
Dry extract colour | Chromatic values | ||||||
|---|---|---|---|---|---|---|---|
% | O.D 420 nm | L* | a* | b* | C* | h* | |
1—Fresh extract | |||||||
Total | 100 | 0.60 | 46.6 | 7.3 | 21.1 | 22.3 | 1.2 |
a—ellagitannins | 70.4 | 0.25 | 37.1 | 6.3 | 17.3 | 18.4 | 1.2 |
b—EP complex | 29.6 | 0.35 | 32.9 | 5.5 | 17.9 | 18.7 | 1.3 |
2—Oxidised extract1 | |||||||
Total | 100 | 0.82 | 39.1 | 13.7 | 34.6 | 37.2 | 1.2 |
a—ellagitannins | 27.6 | 0.20 | 48.7 | 8.8 | 29.1 | 30.4 | 1.3 |
b—EP complex | 72.4 | 0.62 | 25.1 | 3.7 | 9.9 | 10.5 | 1.2 |