Cerreti Martina, Fidaleo Marcello, Benucci Ilaria, Liburdi Katia, Tamborra Pasquale, Moresi Mauro
Dept. for Innovation in Biological, Agro-Food, and Forest Systems, Univ. of Tuscia, Via S. C. de Lellis, 01100, Viterbo, Italy.
CRA - Experimental Institute of Enology, SOP Barletta, Via Vittorio Veneto 26, 70051, Barletta, Italy.
J Food Sci. 2016 Jul;81(7):C1603-12. doi: 10.1111/1750-3841.13344. Epub 2016 May 30.
The ethyl carbamate (EC) content of a wine after a given temperature-time storage was theoretically predicted from the potential concentration of ethyl carbamate (PEC), as determined via an accelerated EC formation test. Such information was used to decide whether an enzymatic treatment was needed to reduce the wine urea level before bottling/aging. To this end, 6 white, red, and rosé wines, manufactured in Italy as such or enriched with urea, were tested for their PEC content either before or after enzymatic treatment using a purified acid urease preparation derived from Lactobacillus fermentum. The treatment was severely affected by the total phenolic content (TP) of the wine, the estimated pseudo-first-order kinetic rate constant for NH3 formation reducing by a factor of approximately 2000 as the TP increased from 0 to 1.64 g L(-1) . Such a sensitivity to TP was by far greater than that pertaining to a killed cell-based enzyme preparation used previously. Urea hydrolysis was successful at reducing EC concentration in wines with low levels of TP and other EC precursors.
根据通过加速氨基甲酸乙酯（EC）形成试验测定的氨基甲酸乙酯潜在浓度（PEC），从理论上预测给定温度-时间储存后葡萄酒中的氨基甲酸乙酯（EC）含量。这些信息用于决定在装瓶/陈酿前是否需要进行酶处理以降低葡萄酒中的尿素水平。为此，对6种在意大利生产的白葡萄酒、红葡萄酒和桃红葡萄酒（原样或添加了尿素），使用源自发酵乳杆菌的纯化酸性脲酶制剂，在酶处理前后测试其PEC含量。该处理受到葡萄酒总酚含量（TP）的严重影响，随着TP从0增加到1.64 g L⁻¹，氨形成的估计准一级动力学速率常数降低约2000倍。这种对TP的敏感性远高于先前使用的基于死细胞的酶制剂。在低TP水平和其他EC前体的葡萄酒中，尿素水解成功降低了EC浓度。
