Abstract:Copper-attapulgite (Cu-ATT), zinc-attapulgite (Zn-ATT), and iron-attapulgite clay (Fe-ATT) composites were developed for artificial aging of Luzhou-flavor liquor. The compositions of metallic elements and microstructural morphology of these composites were characterized by inductively coupled plasma mass spectroscopy (ICP-MS), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The flavor components and metal content of liquor samples were analyzed using gas chromatography-flame ionization detection (GC-FID) and ICP-MS. The results showed that Cu-ATT and Zn-ATT samples exhibited an increase in ethyl acetate and ethyl caproate content and a decrease in acetic acid and hexanoic acid content compared with the control samples. However, this is inconsistent with known changes in the content of acids and esters in naturally-aged liquor. In addition, flavor of these liquor samples was unpleasant, with a high concentration of metallic elements detected. On the other hand, Fe-ATT liquor sample exhibited decreased content of ethyl acetate and ethyl caproate, with increased content of acetic acid and hexanoic acid, which is consistent with known changes in the components of naturally-aged liquor. Furthermore, Fe-ATT liquor sample exhibited pure flavor, a full and well-balanced body, and a clean taste. Additionally, the Fe concentration detected was low and the aging effect was significant. Further investigation is required to ascertain whether the aging effect of Fe-ATT is associated with introduction of Fe element.
