Hydrolysis of fructans from Agave tequilana Weber var. azul during the cooking step in a traditional tequila elaboration process

In traditional tequila production, the heads of Agave tequilana Weber var. azul are cooked in brick ovens to hydrolyze the fructan content and release fermentable sugars. The juice generated during cooking (known as “cooking honey”) was collected periodically in a tequila distillery and characterized to study the efficiency of fructan hydrolysis. The complex structure of fructans from A. tequilana was confirmed. The generation of 5-(hydroxymethyl)-furfural, an increase in absorbance and °Brix, and a decrease in pH and apparent average degree of polymerization of fructans during cooking were observed. The conversion of fructans in the flowing honey increased gradually from 20% at the onset of cooking to 98% after 25.5 h, where fructose represented more than 80% of the total carbohydrates. The proportion of non-hydrolyzed fructans in the cooking honey collected before this time resulted in a total ethanol loss of 6% in the tequila distillery investigated.