and Magazine of the Ceylon Agricultural Society.— Feb., 1910. 171 



rapidly than in the other two ; therefore, as soon 

 as one tray was completely dry, it was removed 

 and replaced by the one just above it. The tem- 

 perature of the entering air was 56°C. and of 

 the escaping air 50°C. The actual time of dry- 

 ing was: Top tray, W 2 hours ; middle tray, 12J 

 hours; and bottom tray, 9J hours. The less 

 completely dried copra in the two upper trays 

 became slightly "soured" while standing over 

 night. This caused a slight increase in free acid 

 as follows:— Top tray, 0'32, middle tray, 0'15 

 and bottom tray, - 13 per cent of free fatty acid. 



In the third experiment the meat from four 

 nuts was shredded and placed in the bottom 

 tray, being stirred every half-hour. The tem- 

 perature of entering air was 93^0. and of esca- 

 ping air 74°0. The time of drying, 3£ hours. 

 The copra thus produced was thoroughly dry, 

 very white, and pleasant to the taste. The oil 

 expressed from it contained only 0'06 per cent 

 free fatty acid. 



A fourth experiment was undertaken in an 

 endeavour to ascertain the approximate time 

 required completely to dry the fresh meat, in- 

 troducing it at the top of the apparatus and 

 shifting it gradually toward the bottom. Four 

 trays, each containing the freshly grated meat 

 of four coconuts, were prepared, and three of 

 these were placed in the drier simultaneously, 

 tray No. 1 being at the bottom. After the latter 

 had become sufficiently dry, it was removed 

 from the apparatus and tray JNo. 2 moved down 

 to take its place ; this was next replaced by Ho. 

 3, and finally in the same manner by the moist 

 sample No. 4. The temperature of the entering 

 air was 95^0. and of the escaping air 70»C. The 

 actual time of drying was : No. 1. 4| hours ; No. 2, 

 h\ hours; No. 3, 6| hours; and No. 4, 4 hours. 



In another experiment with a rotary drier a 

 section of galvanized-irou pipe, 20 centimetres 

 in diameter by 6 metres long, was set up on 

 wheels and connected with a small eiectric 

 motor so that it could be made to revolve at any 

 desired speed. The same current of hot air which 

 was previously used for the stationary drier was 

 connected with this apparatus. Four strips of 

 angle iron, extending throughout the length of 

 the pipe, served to 



KEEP XHE MOIST COPEA IN CONSTANT MOTION 

 DURING THE TIME OF DRYING. 



It was found the grated meat from four nuts 

 could by careful manipulation be dried in about 

 2 hours so as not to contain more than 6 per cent 

 of moisture. The only objection to this method 

 consists in the difficulty of regulating the speed 

 with which the ground meat passes from one 

 end of the apparatus to the other. When per- 

 fected, this method should prove the ideal one 

 for drying coconut meat for oil-making purposes. 



In several vacuum drying experiments the 

 apparatus used was a small, barrel-shaped iron 

 chamber, about 34 centimetres in diameter and 

 in length, insulated with asbestos and heated 

 by three hollow steam plates upon which 

 the substance to be dried was placed. The 

 pump connected with this drier gave a vacuum 

 of about 660 millimetres ( absolute pres- 

 sure of 100 millimetres.) In the first experi- 

 ment four coconuts (the maximum capacity 

 of the apparatus) were split in halves, after 



removing the outer husk, and kept in the 

 drier for three hours. The meat had then 

 contracted sufficiently to allow of its being 

 removed from the shell. During this time 

 the temperature had gradually risen from 30° 

 to 80°. The meat was then subjected to a 

 further drying during four hours, at the end 

 of which time, though not perfectly anhy- 

 drous, it was fully as dry as the ordinary 

 commercial article. The actual time of drying 

 was 7 hours ; maximum temperature, 80° 0. ; 

 vacuum, 635 millimetres ; steam pressure, 

 about 0*7 kilo per square centimetre (10 pounds). 

 Other vacuum experiments showed that under 

 the best conditions obtainable (temperature 85° 

 and vacuum 635 to 660 millimetres,) the mini- 

 mum time required for vacuum drying was five- 

 and-a-half hours. It should be borne in mind, 

 however, that the quality of the 



COPRA PRODUCED BY THE HOT-AIR BOX DRIER 

 IS VERY MUCH SUPERIOR 



to that yielded by any other method, since it is 

 perfectly white and dry, retaining the pleasant 

 odour and taste of fresh coconut meat. For oil- 

 making purposes the rotary apparatus, because 

 it lends itself to a continuous process and re- 

 quires considerably less time, recommends itself 

 especially, although its product does not pre- 

 sent quite so pleasing an appearance. Either 

 of these two methods, on account of their cheap- 

 ness and simplicity, should be preferred to 

 vacuum drying. 



Still another method of drying that has been 

 suggested is "Centrifugating.'' This is to 



EXTRACT THE MEAT FROM COCONUTS BY MEANS 

 OF A ROTARY BURR 



and to run this product directly into a powerful 

 centrifugal, from which the greater part of the 

 water would be thrown oft at once, A compara- 

 tively short, supplementary drying by means of 

 hot air would then suffice to prepare copra for 

 expressing the oil. Another point in favour of 

 this method is that copra resulting therefrom, 

 having lost most of its sugar and albuminoids — 

 together with its water — in the process of centri- 

 fugation, would be able to withstand a higher 

 temperature while drying (with a resulting eco- 

 nomy of time) without showing the same ten- 

 dency to turn brown. Once dry, it could be 

 stored with less danger of deterioration through 

 mould action than material prepared by ordi- 

 nary methods. The objection may be raised that 

 during the centrif ligation, a considerable amount 

 of oil— together with the water — would be thrown 

 off from the fre3h meat, and that this would 

 either entirely be lost or would necessitate 

 much labour for its recovery This, to a cer- 

 tain extent, is true, as the water in coconut 

 meat exists in the. form of a cream-like em- 

 ulsion with oil, sugar, and albuminoids. A 

 sample of this " coconut cream," prepared 

 by expressing the fresh meat in a hand-press, 

 was, on analysis, found to have a specific gra- 

 vity of 1 - 012 at 30° O. and to consist of : — 



Per cent. 



Water .. .. .. 56-3 



Total solids.. .. .. 43-7 



Ash .. .. .. 1-2 



Fat .. .. .. 33-4 



Proteid (N 4- 6 25) .. .. 41 



Total sugar as invert sugar . . 5'0 



