xii. a. s Brill, Parker, and Yates: Copra and Coconut Oil 73 



of the molds survive a temperature of 50° C. for from nine to 

 twelve hours, since removal from the oven permitted both ger- 

 mination and growth to proceed at the normal rate. 



ABSORPTION OF WATER BY COPRA 



The question may be asked, will copra once thoroughly dried 

 absorb enough moisture from the atmosphere during storage to 

 raise its moisture content to a point where molds may grow? 

 Should this occur, what is the use of thorough drying, if during 

 subsequent storage and shipment mold will gain a foothold and 

 destroy a high percentage of the oil and impair the quality of 

 the remainder? This is a most important question from the 

 point of view of the copra dealer, and in .order to formulate an 

 answer, a number of variable factors must be taken into con- 

 sideration. 



Generally speaking, it has been our experience that when 

 dried to a moisture content of about 6 per cent copra does not 

 mold when stored where there is a circulation of air. However, 

 when kept in a saturated atmosphere, it will eventually absorb 

 enough water to enable mold to grow, but this only takes place 

 after it has been exposed to such conditions for from one 

 to two weeks. It would probably very rarely happen that the 

 air in a warehouse or in the hold of a ship will reach a point 

 of saturation and, if this does occur, that the humidity will be 

 replenished when it is absorbed by the copra and that these con- 

 ditions will last for so long a period even as one week. Copra 

 which has been dried only to about 7.5 per cent of moisture often 

 will not grow mold in the open air probably because the surface 

 is really dried out below this moisture content, but when stored 

 under the same conditions as above, will develop mold in from 

 two to five days. 



Another factor which has an influence is the role played by 

 the water liberated during the processes of metabolism of the 

 mold. Mold grows at the expense of the oil and fiber of the 

 copra, converting them into water and carbon dioxide. If the 

 lower part of a large pile of copra contains sufficient water to 

 permit molds to grow, the whole may mold, due to the water 

 that is liberated during mold growth being confined in the 

 pile long enough for the remainder of the copra to absorb enough 

 moisture in turn to support mold growth. 



All of our experiments tend to show that copra once properly 

 dried to approximately 6 per cent moisture does not absorb suf- 

 ficient water, unless in a saturated atmosphere for prolonged 

 periods of time, to develop even a superficial growth of mold. 



