Am.  Jour.  Pharm. 
Jan.,  1885. 
Analysis  of  Malt  Extract. 
15 
NoWj  if  we  accept  these  figures  as  a  basis,  we  can  easily  express  in 
figures  the  value  of  a  malt  extract  with  respect  to  the  diastase. 
Malt  Extract ;  Determination  of  Diastase. — Among  many  technical 
analyses  I  have  performed  248  analyses  of  malt  extract.  The  extract 
was  prepared  by  me,  using  120  bushels  of  malt,  34  lbs.  to  the  bushel, 
in  each  case,  the  malt  being  previously  examined  as  to  its  diastatic 
value.  The  figures  given  further  on  represent  the  average  of  these 
248  analyses. 
The  method  frequently  followed  of  allowing  the  malt  extract  to  act 
from  12  to  24  hours  on  a  large  amount  of  starch  should  be  rejected, 
because  the  changes  occurring  hereby  are  not  always  caused  by  the 
diastase;  for  instance,  the  generation  of  acid,  which  increases  steadily, 
takes  part  in  the  transformation  of  the  starch  ;  further,  the  decompo- 
sition of  the  nitrogenous  bodies,  which  interfere  with  the  action  of  the 
diastase,  or  may  altogether  destroy  it.  It  is  certain  that  this  change 
takes  place  quicker  in  the  human  stomach  : 
1.  Because  the  transformation  of  the  starch  is  in  part  effected  previ- 
ously by  the  baking  and  boiling  of  our  food. 
2.  The  transformation  products  are  speedily  absorbed  in  so  great  a 
measure  that  thereby  the  diastatic  effect  is  accelerated. 
3.  In  the  process  of  digestion  acids  are  produced,  which  support  the 
action  of  the  diastase  until  the  amount  becomes  too  great,  after  which 
the  diastase  is  destroyed,  and  the  acids  act  only  on  the  nitrogenous 
bodies. 
The  diastase  acts  on  starch  paste  very  quickly,  and  the  time  required, 
therefore,  is  only  to  be  reckoned  by  minutes.  Such  action  should  con- 
tinue no  longer  than  1  hour,  because  a  watery  solution  of  malt  extract 
begins  to  decompose  after  1  hour.  A  solution  changing  the  starch 
paste  in  5  minutes  will  after  6  to  10  hours  require  12  to  15  minutes. 
These  are  the  principal  reasons  why  I  use  smaller  amounts  of  starch, 
and  set  down  as  standard  the  time  required  for  transformation. 
In  order  to  prove  the  action  of  the  diastase  in  the  stomach,  as  indi- 
cated above  under  No.  2,  recourse  may  be  had  to  the  dialisator,  with 
which  the  following  experiment  was  made. 
One  part  malt  extract  was  mixed  with  100  ])arts  by  weight  of 
starch  which  had  previously  been  boiled  to  a  paste  with  2,500  parts  of 
water.  One-half  of  this  mixture  was  placed  in  a  dialisator,  the  other 
half  in  a  closed  bottle.  Botli  portions  were  placed  in  water,  and 
exposed  to  a  temperature  of  150°F.  for  24  hours,  the  water  into 
