Extraction, characterization and quantification of the fructans contained in head and leaves of Agave tequilana Weber azul

Heads and leaves of ten Agave tequilana Azul plants were collected; leaves were classified as young, mature, and dry; mature leaves were divided into bases and tips, and the contribution of each fraction in the plant total weight was determined. Heads, bases, and tips were dried and ground to get their respective flour. Chemical analysis, dietary fiber content and optimal conditions (water-solid ratio, temperature, and soaking time) to extract fructans from each flour were performed. Determination in extracts included direct reducing sugars (DRS) and total (TRS), inulin and fructooligosaccharides (FOS), glucose (G) and fructose (F), the average degree of polymerization (ADP) and average molecular weight (AMW) of the fructans. It was found that the agave plants were composed by: head (53.7 %), mature leaves (38.6 %; bases 23.8 % and tips 14.8 %), dry leaves (5.8%), and young leaves (1.9 %). Carbohydrates represent the main constituent of all fractions of agave and are integrated by: heads (TRS 80.20 %; inulin 43.24 %, FOS 24.96% and DRS 12.00 %), bases (TRS 56.36 %; inulin 24.52 %, FOS 13.66% and DRS 18.18 %), and tips (TRS 26.3 %; inulin 2.25 %, FOS 6.24 % and DRS 17.81 %). Inulin and FOS present in the head of agave have greater ADP and AMW. According to their carbohydrate profile, heads and bases of mature leaves of agave plants can be used for the production of high fructose syrups, crystalline fructose, inulin and FOS, products widely used in the food and beverage industry.