Phenolics extraction from Agave americana (L.) leaves using high-temperature, high-pressure reactor

The Agave americana plant has been largely used in traditional medicine. The setting up of efficient methods for phenolics extraction from A. americana leaves is one of great interest. With the aim of optimizing phenolics extraction from this material, the effects of temperature (from 25 to 150 °C) and extraction time (from 15 to 240 min) were investigated using a high-temperature, high-pressure (PARR) reactor, under either air or nitrogen atmosphere. Total polyphenols and flavonoids were determined, and their antioxidant activity was measured by the DPPH radical method. The use of PARR reactor for phenolics extraction proved to be more efficient compared to the conventional solid–liquid extraction at room temperature. The results of this work demonstrated that an increase in both temperature and extraction time led to a corresponding increase in the amount of phenolic compounds extracted and suggested that, after process optimization, this material could be used as an interesting alternative source of polyphenols.

Research highlights▶ The use of the high-temperature, high-pressure (PARR) reactor is proposed for optimizing the extraction of phenolic compounds from A. americana leaves. ▶ The increase in both temperature and extraction time led to a corresponding increase in the amount of phenolic compounds extracted. ▶ The maximum contents of phenolics (23.8 mgQe g−1DW) and flavonoids (15.5 mgQe g−1DW) were obtained at 150 °C after 240 min under nitrogen atmosphere. ▶ As a result of the important antioxidant activity of the A. americana leaves extract, this biomass might be used in different industries, such as the pharmaceutical and cosmetic ones, after additional purification processes.