Extraction of polysaccharides
Ground fresh fruit rind were dried in hot-air oven at 60C.which gave 19.6+-1.4% w/w of dried material.The dried sample was extracted with water at 90-100C adjusted to pH 4.5 with citic acid and purified as described previously (Pongsamart &Panmaung,1998) as illustrated in Fig I Briefly,the water extract was concentrated under reduced pressure and the gel-like precipitate was obtained by addition of acidified aqueous ethanol .The dried precipitate was re-dissolved with water and afterwards concentrated.To the concentrated solution,aqueous ethanol was added and the precipitate was removed. The precipitate was washed twice with 75% ethanol and then 95% ethanol,the dried,ground and sieve (designated as PG)