Morel-Salmi Cécile, Souquet Jean-Marc, Bes Magali, Cheynier Véronique
INRA, UMR Sciences pour l'Oenologie, 2 Place Viala, 34060 Montpellier, France.
J Agric Food Chem. 2006 Jun 14;54(12):4270-6. doi: 10.1021/jf053153k.
The flash release (FR) process, consisting of rapidly heating the grapes and then applying strong vacuum, has been proposed to increase the polyphenol content of red wines. Its impact on polyphenol extraction kinetics and on the polyphenol composition of red juice and wines was studied over two seasons on different grape varieties (Grenache, Mourvedre, Carignan). The FR process allows fast extraction of all phenolic compounds (hydroxycinnamic acids, flavonols, anthocyanins, catechins, proanthocyanidins) and can be used to produce polyphenol-enriched grape juices. However, the concentration of all polyphenols dramatically decreased throughout fermentation when pressing was achieved immediately after FR. The FR wines made with pomace maceration were also enriched in polyphenols compared to the corresponding control wines. Increasing the duration of high-temperature exposure in the FR treatment further increased extraction of phenolic compounds but also accelerated their conversion to derived species. The tannin-to-anthocyanin ratio was particularly low in the wine fermented in the liquid phase, higher after FR than in the control, and even higher after longer heating. FR resulted in an increased tannin-to-anthocyanin ratio and an increased conversion of anthocyanins to tannin-anthocyanin adducts showing the same color properties as anthocyanins. The tannin-to-anthocyanin ratio was particularly low in the wine fermented in the liquid phase that also contained larger amounts of orange sulfite bleaching-resistant pigments.
闪蒸（FR）工艺，即先快速加热葡萄然后施加强真空，已被提议用于提高红葡萄酒的多酚含量。在两个季节里，针对不同葡萄品种（歌海娜、慕合怀特、佳丽酿）研究了该工艺对多酚提取动力学以及对红葡萄汁和葡萄酒多酚组成的影响。FR工艺能够快速提取所有酚类化合物（羟基肉桂酸、黄酮醇、花青素、儿茶素、原花青素），可用于生产富含多酚的葡萄汁。然而，若在FR后立即进行压榨，所有多酚的浓度在整个发酵过程中会大幅下降。与相应的对照葡萄酒相比，采用皮渣浸渍法酿造的FR葡萄酒也富含多酚。在FR处理中增加高温暴露时间进一步提高了酚类化合物的提取量，但也加速了它们向衍生种类的转化。在液相中发酵的葡萄酒中单宁与花青素的比例特别低，FR处理后的该比例高于对照，加热时间更长后比例更高。FR导致单宁与花青素的比例增加，花青素向单宁 - 花青素加合物的转化增加，这些加合物具有与花青素相同的颜色特性。在液相中发酵的葡萄酒中单宁与花青素的比例特别低，该葡萄酒还含有大量橙色抗亚硫酸盐漂白色素。
