Effect of Thermal Process and Filtration on the Antioxidant Activity and Physicochemical Parameters of Agave atrovirens Extracts

Recently agave plants are being used in the production of syrups that are consumed by diabetic people in order to control their blood glucose levels; unfortunately a deep characterization of this kind of products has not been made. In this study the juice obtained from Agave atrovirens leaves (CE) was filtered and cooked (FE) and evaporated until it has a solid content of 20 ºBx (TE), and the effect of the process in some parameters like pH, acidity, solid content, 5-Hydroxymethylfurfural (5-HMF) and compounds with biological properties like saponins and phenolic compounds as well as antioxidant activity were evaluated. Once FE was concentrated, a dark brown liquid with a pH of 5.32 was obtained; the content of phenolics and saponins undergoes slightly modifications trough the complete process. 5-HMF was only detected in CE but not in FE and TE. Filtering decrease acidity, total phenolics, saponins, 5-HMF and the antiradical activity (ARA); and evaporation increase the content of reducing sugars and tends to increase the ARA value. For this study, we can conclude that the negative impact associated to a thermal process on bioactive compounds like phenols and antioxidant activity is negligible hence Agave atrovirens leaves could be a source of a product with phytochemicals.