Compressional-puffing pretreatment for enhanced antioxidant compounds extraction from Aloe vera

Compressional-puffing pretreatment is an efficient pretreatment process that can enhance extraction efficiency of bioactive compounds from plants. In this study, raw and pre-dried Aloe vera at moisture content 0–42.47 g/g dried biomass was puffed at 200 °C for 20 s and was extracted using 60% v/v ethanol solution at 70 °C for 1 h. Pre-drying with 80 °C thermal drying or −50 °C freeze-drying produced mediate sized pores which do not release the targeted bioactive compounds from Aloe biomass. Conversely, the puffing yielded numerous 0.1‒5 µm pores that contributed to the enhanced extraction efficiencies. There presents a moisture content (1 g/g dry material) that maximized the extraction yield of bioactive compounds, which denoted the compromise between thermal inertia to heat up at too much water and explosion expansion strength to be produced at too few water in biomass. The even distribution of water in biomass subjected to puffing was proposed essential to efficient puffing treatment of the biomass.