Development on Saponin Extraction from Rambutan Peel and the Efficacy Test of Saponln

Abstract

Development on saponin extraction from rambutan peel and its efficacy testwas carried out aiming to gain the most effective technique for this. Hence, agricultural waste as such rambutan peel can be utilized. The research was conducted at Chanthaburi Horticultural Research Center during September 2011 to October 2014. It was included testing and verifying of extraction techniques, identification and quantification of saponin, and efficacy test of saponin. Two extraction techniques, soaked and reflux extraction, using 3 solvents, 70% ethanol, 70% methanol and distilled water, were compared. The crude extract of which rambutan peel obtained from reflux technique compared with soaked extraction technique for nine days showed that higher the extract dry weight 44% and 33% for only nine hours.The extracts were identified as triterpene and steroid saponin by FTIR. Spectrophotometer was used to quantify the amount of saponin which the reflux extraction using 70% methanol yielded the highest saponin (422.05 mg/g). Therefore, it is the most effective extraction technique as it yielded more amount of saponin than distilled water and 70% ethanol reflux methods, 23% and 14% respectively. Efficacy test indicated that applied saponin solution at 2,000 and 4,000 mg/L to channeled apple snail (Pomacea canaliculata) could effectively kill the snail within 12 h. Moreover, when mixed saponin with PDA at 2,000 mg/L, it could effectively inhibited growth of the 3 fungal pathogen, Phytophthora palmivora, Colletotrichum spp. and Marasmius palmivorus Sharples,compared to control.