Effect of ultrasound intensification on the supercritical fluid extraction of phytochemicals from Agave salmiana bagasse

The aim of this work was to evaluate the effect of ultrasound on supercritical fluid extraction for the recovery of antioxidants and saponins from agave bagasse as a green extraction technique. When a mass load of 0.086 g/cm(3) was used, ultrasound effect was not observed, due to sample swelling and compaction within the cell. For 0.043 g/cm(3), the intensification effect of ultrasound was significant (p < 0.05) and its magnitude depended on the transducer geometry. For a multiplate transducer geometry, antioxidant capacity increased from 12.18 +/- 1.01 to 20.91 +/- 1.66 mu mol TE/g; and saponins from 19.05 +/- 1.67 to 61.59 +/- 1.99 mu g/g, when ultrasound was applied. Although the amount of bioactives extracted is low, the use of a multiplate transducer design was able to intensify the supercritical fluid extraction of phytochemicals from agave bagasse. Consequently, this type of transducer can become an alternative for the application of ultrasound on the supercritical fluid extraction of other suitable agro-industrial by-products.