78 The Philippine Journal of Science wx 



dirt and to secure more complete drying with facilities to protect 

 it during short rainy periods. Pratt J0 states that copra produced 

 in other countries by like means commands a higher price than 

 Philippine copra and must be considered as superior in the 

 world's market. 



MECHANICAL DRYERS 



Mechanical dryers are one possible solution of the problem 

 for improving the copra production of the Islands, but they 

 have not been introduced in a commercial way. Several ma- 

 chines have originated in the Philippines that require consider- 

 able handling of the meat, but while their product is of good 

 quality, initial and operating expenses seem to be too great to 

 warrant their adoption. Smith 1T gives descriptions and draw- 

 ings of several types of drying machines. At two of the copra- 

 oil mills here large hot-air dryers have been installed for redry- 

 ing copra before it is milled. This apparatus, with changes, 

 might be adapted to the drying of fresh meat. It has the ad- 

 vantage over other forms of dryers in being a continuous process 

 with the minimum amount of handling of the product. A small 

 cheaply constructed dryer, combining low operating expenses 

 and rapid drying, would find a ready market in the Philippines. 



Mechanical drying machines have been discredited by the pub- 

 lic through the belief that when coconut meat is dried in a 

 current of hot air a part of the oil is carried away from the 

 copra. This supposition is not in accord with what one might 

 expect from a study of the physical properties of coconut oil. 

 It was found that when coconut oil was heated for four hours 

 in a current of hot air at 100° C. there was no appreciable loss 

 in weight. 



Pure coconut oil was dried in vacuum over sulphuric acid for 

 four days, after which it was heated in an oven at 100° C. for 

 four hours with the following results : 



Table XVII. — Loss on heating coconut oil at 100" C. for four hours. 



Oil No. 



Weight of 

 oil. 



Weight 

 lost. 





0. 



i. 9112 

 4.S919 

 3.9282 

 4. 7955 



Per cent. 



0.024 

 0.022 

 0.023 







1 IV 



1 





11 Op. cit. 



" Smith, H. Hammel, Coconuts. The Consols of the East. Tropical Life, 

 London (1913). 



