2  MATERIALS AND METHODS 
2.1  Isolation of Amylase Enzyme from 
Durian Seed Sprouts 
Durian  seeds  are  washed  with  running  water  and 
then put into a container for the germination process, 
prepared  by  growing  media  and  then  waited  for 
durian seed germination for 5 days. 150 grams of 5 
days  durian  seed  sprouts  obtained  were 
homogenized  with  250  ml  of  1%  Isotonic  NaCl 
solution  in  a  cold  state.  Then  mashed  and  filtered 
until  the  filtrate  and  pulp  separate.  The  filtrate  was 
centrifuged  at  10,000  rpm  at  20C  for  10  minutes. 
The  crude  of  enzyme  produced  was  tested  for  its 
activity  against  temperature  variations  (30,  35,  40, 
45  dan  50C),  pH  (3,  5,  7,  dan  9)  and  Substrate 
concentration  (0,5;  1;  1,5;  2;  dan  2,5%  w/v).  The 
resulting  enzyme  crude  is  purified  by  varying  the 
saturation level of ammonium sulfate (20, 40, 60 dan 
80%  w/v)  then  the  purification  results  of  each 
variation  were  tested  their  activity  back  to  the 
optimum  temperature,  pH  and  substrate 
concentrations  to  determine  the  activity  of  the 
resulting amylase enzyme after purification.
 
2.2  Crude Amylase Enzyme Activity 
Test on Variation of Temperature 
0.5  mL  of  1%  starch  solution  was  put  into  the  test 
tube  then  added  5  mL  of  buffer  phosphate  pH  7. 
Added 1 mL of crude amylase enzyme extract and 1 
ml  of  1%  NaCl.  Then  incubated  at  temperature 
variations  (30,  35,  40,  45  and  50  0C)  for  1  hour. 
After  that,  1  mL  of  0.1N  NaOH  was  added  and 
centrifuged at 3400 rpm for 20 minutes. 1 ml of the 
supernatant  is  taken  and  then  diluted  in  10  ml 
measuring flask and then homogenized. Put 1 ml of 
dilution  results  into  the  test  tube  then  add  1  ml  of 
Nelson’s  reagent  and  heated  in  a  water  bath  for  20 
minutes.  Then  removed  and  cooled  until  the 
temperature 25 0C. 0.5 mL of arsenomolybdate was 
added  and  then  shaken  until  all  the  sediment 
dissolved.  Then  added  7  mL  of  distilled  water  and 
then  shaken  until  homogeneous.  Its  absorption  is 
measured at a wavelength of 645 nm. 
2.3  Crude Amylase Enzyme Activity 
Test on Variation of pH 
0.5  mL  of  1%  starch  solution  was  put  into  the  test 
tube then added 5 mL of buffer phosphate pH 3, 5, 7 
and 9. Added 1 mL of crude amylase enzyme extract 
and  1  ml  of  1%  NaCl.  Then incubated  at  optimum 
temperature  for  1  hour.  After  that,  1  mL  of  0.1N 
NaOH  was  added  and  centrifuged  at  3400  rpm  for 
20 minutes. 1 ml of the supernatant is taken and then 
diluted  in  10  ml  measuring  flask  and  then 
homogenized.  Put  1  ml  of  dilution  results  into  the 
test  tube  then  add  1  ml  of  Nelson’s  reagent  and 
heated in a water bath for 20 minutes. Then removed 
and  cooled  until  the  temperature  25C. 0.5 mL of 
arsenomolybdate  was  added  and  then  shaken  until 
all  the  sediment  dissolved.  Then  added  7  mL  of 
distilled  water  and  then  shaken  until  homogeneous. 
Its  absorption  is  measured  at  a  wavelength  of  645 
nm. 
2.4  Crude Amylase Enzyme Activity 
Test on Variation of Substrate 
Concentrations 
0.5  mL  of  starch  solution  variation  (0,5;  1;  1,5;  2; 
dan  2,5%)  was  put  into  the  test  tube  then  added  5 
mL of  buffer phosphate  optimum pH.  Added  1 mL 
of  crude  amylase  enzyme  extract  and  1  ml  of  1% 
NaCl. Then incubated at optimum temperature for 1 
hour. After that, 1 mL of 0.1N NaOH was added and 
centrifuged at 3400 rpm for 20 minutes. 1 ml of the 
supernatant  is  taken  and  then  diluted  in  10  ml 
measuring flask and then homogenized. Put 1 ml of 
dilution  results  into  the  test  tube  then  add  1  ml  of 
Nelson’s  reagent  and  heated  in  a  water  bath  for  20 
minutes.  Then  removed  and  cooled  until  the 
temperature  25C.  0.5  mL  of  arsenomolybdate  was 
added  and  then  shaken  until  all  the  sediment 
dissolved.  Then  added  7  mL  of  distilled  water  and 
then  shaken  until  homogeneous.  Its  absorption  is 
measured at a wavelength of 645 nm. 
2.5  Crude Amylase Enzyme Activity 
Test after Purification with 
Ammonium Sulfate 
0.5 mL of starch solution optimum variation was put 
into  the  test  tube  then  added  5  mL  of  buffer 
phosphate  optimum  pH.  Added  1  mL  of  crude 
amylase  enzyme  extract  after  purification  with 
variations  in  the  saturation  level  of  ammonium 
sulfate (20, 40, 60 dan 80%) and 1 ml of 1% NaCl. 
Then  incubated  at  optimum temperature for  1 hour. 
After  that,  1  mL  of  0.1N  NaOH  was  added  and 
centrifuged at 3400 rpm for 20 minutes. 1 ml of the 
supernatant  is  taken  and  then  diluted  in  10  ml 
measuring flask and then homogenized. Put 1 ml of 
dilution  results  into  the  test  tube  then  add  1  ml  of