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In contrast to the hydrolysis of reserve carbohydrates in most plant-derived alcoholic beverage processes carried out with enzymes, agave fructans in tequila production have traditionally been transformed to fermentable sugars through acid thermal hydrolysis. Experiments at the bench scale demonstrated that the extraction and hydrolysis of agave fructans can be carried out continuously using commercial inulinases in a countercurrent extraction process with shredded agave fibers. Difficulties in the temperature control of large extraction diffusers did not allow the scaling up of this procedure. Nevertheless, batch enzymatic hydrolysis of agave extracts obtained in diffusers operating at 60 and 90 degrees C was studied at the laboratory and industrial levels. The effects of the enzymatic process on some tequila congeners were studied, demonstrating that although a short thermal treatment is essential for the development of tequila's organoleptic characteristics, the fructan hydrolysis can be performed with enzymes without major modifications in the flavor or aroma, as determined by a plant sensory panel and corroborated by the analysis of tequila congeners.

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Five agave plants typically used in Mexico for making mezcal in places included in the Denomination of Origin (Mexican federal law that establishes the territory within which mezcal can be produced) of this spirit were analyzed: Agave salmiana ssp. crassispina, A. salmiana var. salmiana, Agave angustifolia, Agave cupreata, and Agave karwinskii. Fatty acid and total simple lipid profiles of the mature heads of each plant were determined by means of a modified Bligh-Dyer extraction and gas chromatography. Sixteen fatty acids were identified, from capric to lignoceric, ranging from 0.40 to 459 microg/g of agave. Identified lipids include free fatty acids, beta-sitosterol, and groups of mono-, di-, and triacylglycerols, their total concentration ranging from 459 to 992 microg/g of agave. Multivariate analyses performed on the fatty acid profiles showed a close similarity between A. cupreata and A. angustifolia. This fact can be ascribed to the taxa themselves or differences in growing conditions, an issue that is still to be explored. These results help to characterize the agaves chemically and can serve to relate the composition of mezcals from various states of Mexico with the corresponding raw material.

An optimized sol-gel technique was used for the entrapment of 2,4-dichlorophenoxyacetic acid (2,4-D) antibodies in a silica matrix derived from tetraethoxysilane (TEOS). Immunoextraction cartridges with reproducible binding capacity for 2,4-D methyl ester (test solute) were prepared from the doped dry gels and wet hydrogels. Although the surface of these biomaterials was characterized by wide macropores, there was no evidence of antibody leakage, as demonstrated by the good precision of the results obtained from repeated extractions performed in the same cartridge. The 2,4-D antibody (commercially obtained), free or encapsulated, was highly selective toward the esterified 2,4-D molecule. Optimal extraction was achieved from samples containing phosphate buffer 0.01-0.15 M (pH ∼7), which were loaded at a maximal flow rate of 1 mL min -1 in cartridges left under buffer for at least 30 min between consecutive experiments. Recoveries of 100%, for loaded ester amounts lower than the cartridge capacity, were obtained under these conditions. A binding capacity of 130 ng of 2,4-D ester per mg of immobilized antibody, corresponding to 42% of the free antibody activity, was obtained with the best gels. The capacity of these immunosorbent cartridges remained practically constant during eight weeks or 50-60 adsorption-desorption cycles.