Grupo VIENAP, Instituto de Ciencias de la Vid y del Vino (CSIC, Universidad de La Rioja, Gobierno de La Rioja), Ctra. de Burgos, Km. 6, 26007, Logroño, Spain.
Departamento de Estadística e Investigación Operativa Aplicadas y Calidad, Universidad Politécnica de Valencia, Camino de la Vera s/n, 46022, Valencia, Spain.
Anal Chim Acta. 2022 Sep 15;1226:340254. doi: 10.1016/j.aca.2022.340254. Epub 2022 Aug 14.
It is well known that grape aromatic composition is directly correlated to the final wine quality. To determine this composition, a previous stage of selective extraction is necessary, since the aromatic compounds are found in very low concentrations in the grapes. Therefore, in this work, the thin film microextraction technique (TF-SPME) was optimized, for first time, with the aim to analyze the volatile composition of the grape musts. The results obtained with the two commercially available absorbent materials for TF-SPME, polydimethylsiloxane/carboxene (PDMS/CAR) and PDMS/divinylbenzene (PDMS/DVB), were optimized and compared. To carry out the optimization, a randomized factorial design was performed combining the following factors and levels: extraction mode (headspace (HS), or direct immersion (DI)), stirring speed (500 and 1000 rpm), extraction time (1, 3 and 6 h), and extraction temperature (20, 40 and 60 °C). After performing a principal component analysis (PCA) and an analysis of variance (ANOVA) multifactorial, it was concluded that the best conditions for TF-SPME with PDMS/CAR were: direct immersion (DI), 500 rpm, 6 h, and 20 °C, while for TF-SPME with PDMS/DVB no conditions were found that maximized the extraction of most compounds, therefore compromise conditions were chosen: headspace (HS), 500 rpm, 6 h, and 40 °C. Finally, the comparison between the results obtained with both absorbents indicated that the absorbent that extracted better the volatile compounds from the musts with the TF-SPME technique, was PDMS/CAR, under the conditions: direct immersion (DI), 500 rpm, 6 h, and 20 °C.
众所周知，葡萄的香气成分与最终的葡萄酒质量直接相关。为了确定这种成分，需要进行选择性提取的前期阶段，因为香气化合物在葡萄中含量非常低。因此，在这项工作中，首次优化了薄膜微萃取技术（TF-SPME），旨在分析葡萄汁的挥发性成分。用两种市售的 TF-SPME 吸收剂材料（聚二甲基硅氧烷/羧基（PDMS/CAR）和 PDMS/二乙烯基苯（PDMS/DVB））优化和比较了获得的结果。为了进行优化，采用了随机因子设计，结合了以下因素和水平：提取方式（顶空（HS）或直接浸入（DI））、搅拌速度（500 和 1000 rpm）、提取时间（1、3 和 6 h）和提取温度（20、40 和 60°C）。在进行主成分分析（PCA）和多因素方差分析（ANOVA）之后，得出的结论是，用 PDMS/CAR 进行 TF-SPME 的最佳条件是：直接浸入（DI）、500 rpm、6 h 和 20°C，而用 PDMS/DVB 进行 TF-SPME 则没有找到能够最大限度地提取大多数化合物的条件，因此选择了妥协条件：顶空（HS）、500 rpm、6 h 和 40°C。最后，用两种吸收剂获得的结果进行比较表明，用 TF-SPME 技术从葡萄汁中提取挥发性化合物效果更好的吸收剂是 PDMS/CAR，在以下条件下：直接浸入（DI）、500 rpm、6 h 和 20°C。
