Center for Viticulture and Enology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; Key Laboratory of Viticulture and Enology, Ministry of Agriculture, Beijing 100083, China.
Center for Viticulture and Enology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; Key Laboratory of Viticulture and Enology, Ministry of Agriculture, Beijing 100083, China.
Food Res Int. 2018 Dec;114:214-222. doi: 10.1016/j.foodres.2018.08.016. Epub 2018 Aug 4.
The effect of adding amino acids on wine aroma is largely influenced by nutritional status of grape must. In this study, the effects of linoleic acid (LA) content on the aromatic function of branched-chain amino acids (BCAAs) addition were investigated in alcoholic fermentation of Cabernet Sauvignon wine. The results showed that initial LA content in must significantly influenced the effect of BCAAs addition on volatiles in final wine. Adding BCAAs (140 mg/L of l-leucine, 117 mg/L of l-isoleucine and 118 mg/L of l-valine) in must with low LA content (12 mg/L) promoted the production of most volatiles, including higher alcohols (isobutanol, 2-phenylethanol), fatty acids (hexanoic acid, octanoic acid, decanoic acid) and esters (ethyl acetate, isoamyl acetate, 2-phenethyl acetate and ethyl octanoate), which were well consistent with previous literatures. However, this function disappeared or even became inhibition with increasing LA content in must, especially in 120 mg/L LA must, the total contents of higher alcohol, acetate esters and ethyl esters were 33.9%, 18.1% and 54.2% lower than those in the control without BCAAs addition, respectively. The transcriptional data revealed that several major genes including GAP1, ADH1, ATF1, ACC1, FAS1 and OLE1 were marked repressed by high LA content. Our data indicated that LA can regulate the expressions of related functional genes to efficiently influence the formations of volatiles in BCAAs supplemented wines. Therefore, it is essential to consider initial content of unsaturated fatty acids (LA) in must when using the strategy that supplying amino acids (BCAAs) to modulate aromatic quality of wines.
添加氨基酸对葡萄酒香气的影响在很大程度上受到葡萄汁营养状态的影响。本研究以赤霞珠葡萄酒的酒精发酵为模型，研究了亚油酸（LA）含量对支链氨基酸（BCAA）添加对芳香功能的影响。结果表明，初始 LA 含量显著影响了 BCAAs 添加对最终葡萄酒挥发性物质的影响。在 LA 含量低（12mg/L）的葡萄汁中添加 BCAAs（140mg/L 的 l-亮氨酸、117mg/L 的 l-异亮氨酸和 118mg/L 的 l-缬氨酸）促进了大多数挥发性物质的生成，包括高级醇（异丁醇、2-苯乙醇）、脂肪酸（己酸、辛酸、癸酸）和酯类（乙酸乙酯、异戊酸乙酯、2-苯乙醇乙酸酯和辛酸乙酯），这与之前的文献报道一致。然而，随着初始 LA 含量的增加，这种功能消失甚至抑制，尤其是在 LA 含量为 120mg/L 的葡萄汁中，高级醇、乙酸酯和乙酯的总含量分别比对照组（未添加 BCAAs）低 33.9%、18.1%和 54.2%。转录组数据表明，包括 GAP1、ADH1、ATF1、ACC1、FAS1 和 OLE1 在内的几个主要基因的表达受到高 LA 含量的显著抑制。我们的数据表明，LA 可以调节相关功能基因的表达，从而有效地影响 BCAAs 补充葡萄酒中挥发性物质的形成。因此，在使用补充氨基酸（BCAAs）调节葡萄酒芳香品质的策略时，必须考虑葡萄汁中不饱和脂肪酸（LA）的初始含量。
