6(5 



Table III. 

 Doughs and Bread-Crumb. 



Loaf weights 

 in grams. 



Apparent 

 Moisture 

 per cent. 



Soluble 

 Extract 

 on Bone- 

 dry Solids 

 per cent. 



Colorimetric 



Value of 



Extract with 



standard Iodine 



solution. 



Dough after mixing 

 Dough after proving 

 Bread 6 hours old - 



Bread 70 hours old- 



/ Original 997 \ 

 \fi hours 973 / 

 Original 995'] 

 6 hours 972 I 

 24 hours ^4 )- 

 48 hours 952 

 70 hours 945 



41-21 

 41-10 

 41-42 



41-35 



10-07 



9-76 



12-84 



15-31 



21 red 

 05 yellow 

 Nil. 

 10 blue 

 50 red 



15 blue 

 25 red 



Among other conclusions reached by this research were : — 



1. The loss of water during cooling and drying-out of a loaf is not 

 responsible for staleness. 



2. During the process of becoming stale, there is a faU in soluble 

 extract obtained from the crumb, followed, after a time, apparently 

 independent of staleness, by a rise. The soluble starch in bread- 

 crumb (as shoAvn by the iodine colouration) drojDS rapidly between 

 6 hours' and 24 hours' cooling. 



3. Investigation shows that a similar fall and rise of soluble 

 extract is to be seen in starch pastes, whilst the iodine colouration 

 follows the same rule observed in bread-crumb. 



4. Staleness may be attributed to — 



(i) Deposition of soUd starch in the crumb of bread, starting 

 between 6 hours and 24 hours' cooling period — 

 (a) By change of temperature ; 



(6) Accelerated by the presence of soUd starch particles 

 already existing in the crumb, 

 (ii) Partial polymerisation of starch, independent of the 

 deposition already stated, which tends to crumble the 

 gelatinous nature of the bread-crumb when fresh. 



The statement in 4 (i) (6) is open to dispute, for we have no actual 

 proof that the deposition of solid starch from solution is accelerated 

 by the presence of other solid particles. This work is even now in 

 progress. On the other hand, the statement made in para. 4 (ii) is, 

 we believe, substantially correct, for the following reasons, which 

 must be taken in conjunction ^^ith the figures given in Table II 

 showing the soluble extracts from starch paste decreasing with time, 

 (especially as indicated by the iodine colouration) : — 



If we take the suspension of starch granules in water as the starting 

 point of our consideration, it is seen to be a coarsely disperse system, . 



