Enzymatic Hydrolysis of Fructans in the Tequila Production Process

Abstract

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.

Characterization of Blue Agave Bagasse (BAB) as Raw Material for Bioethanol Production Processes by Gravimetric, Thermal, Chromatographic, X-ray Diffraction, Microscopy, and Laser Light Scattering Techniques

“…Such conditions seem to reduce the extraction of oils and fats from agave pine cuticles. If agave is cooked in brick ovens by steam injection (brick oven and tahona BAB samples) or in autoclave operations (autoclave BAB), the efficient removal of waxes from agave cuticles is promoted, thereby reducing the possible negative organoleptic properties of the final product [4]. Both the nitrogen and protein contents of BAB samples were slightly higher in crude BAB than in the other biomasses, which is directly related to the less intensive conditions used for inulin extraction for crude BAB than when the agave is cooked in brick ovens and autoclaves as is undertaken with autoclave BAB, brick oven BAB and tahona BAB.…”

“…Other factories carry out fructan extraction (process 3, crude BAB) using diffusers in a manner that is optimized to minimize fructan loss in the residual agave fibers. After carbohydrate extraction, thermal/acid hydrolysis of fructans in autoclaves is carried out under reaction conditions similar to those used when fructans are hydrolyzed directly in the pine before extraction [4]. After coking by processes 1 or 2, the cooked agave is passed through a cutter and shredded using a combination of efficient milling and water extraction to recover sugars for the fermentation stage [2,3].…”

Comparison of the water-soluble carbohydrate composition and fructan structures of Agave tequilana plants of different ages

“…These results showed a higher increase in plant growth and sugar accumulation between 2 and 4 years after hijuelos plantation, then variations were less pronounced between 4 and 6½ years. Normally, in the tequila elaboration process, the sugar content present in A. tequilana plants at the harvest point was 129-174 g of fructose/ kg of fresh agave head (Avila-Fernandez et al, 2009). As the sugar contain reached at 6½ years was 123.8 ± 0.87 g of sugars/kg of fresh agave head (Table 1), agave plants of this age could be used for the tequila production with a reduction of harvest time.…”

“…Nevertheless, it has to be taken in account that the use of younger A. tequilana plants decreased the ethanol produced during fermentation and increased the methanol content at the end of fermentation as well as changes in the synthesis of other volatile compounds, which could affect the tequila quality (Pinal et al, 2009). Considering the sugar composition of A. tequilana plants, fructose is the principal momoner of the fructan polymers (Lopez et al, 2003), and as it has normally found that at the harvest point (8 years), the A. tequilana juice used for tequila production has 95% of fructose and 5% of glucose (Avila-Fernandez et al, 2009;Cedeño 1995). Therefore, it could be considered that the fructose content in fructans of A. tequilana plants of 6½ years (Table 1) is higher than 90%.…”

Use of inulinases to improve fermentable carbohydrate recovery during tequila production

“…Recently, the possibility to hydrolyse agave fructans using commercial preparations of fructanases 0308-8146/$ -see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodchem.2010.08.007 developed for food industry was demonstrated (Munoz-Gutierrez, Rodriguez-Alegria, & Munguia, 2009), and a very recent work described the efforts made to introduce these enzymes in the tequila production process (Avila-Fernandez et al, 2009). However, in that work, efforts were concentrated on a tequila production process different from the traditional one, using modern equipments and, thus not following the traditional steps.…”