Sample preparation
Figure 1 shows the process undertaken to prepare saponin-enriched water and ethanol extracts. Briefly,ground leaves were extracted in either water under
optimal conditions identified using RSM (85°C,25 min, water-to-leaf ratio of 100:5 mL g1) or 80%(v/v) ethanol (room temperature for 72 h). The extracted solution was filtered and then concentrated using a rotary evaporator (Buchi Rotavapor B-480,
Buchi Australia, Noble Park, Vic., Australia) under
Table 1
Experimental design for optimisation of water extraction of saponin from papaya leaf and observed response. The influence of temperature, time and water-to-leaf ratio on papaya extraction efficiency was assessed