377 



EDIBLE PRODUCTS. 



Report on a Sample of Coconut "Water" from Ceylon. 



By Professor Wyndham R. Dunstan, m.a., f.r.s. 

 A sample of this material was sent to the Imperial Institute in 1904 by the 

 Secretary of the Ceylon Committee for the St. Louis Exhibition, and is referred 

 to in letters No. 190b. dated the 8th August, 1904, and No. 210b. dated the 23rd 

 October, 1904. 



It was stated in the first of these letters that the Commissioner for Ceylon 

 at the St. Louis Exhibition had reported that a firm in St. Louis was making 

 experiments with a view to the extraction of sugar from the " liquid matter " 

 (water) of the coconut, and it was suggested that it might be worth while to conduct 

 similar experiments at the Imperial Institute with the view of ascertaining 

 whether sugar could be profitably extracted from this material in Ceylon, where 

 it is at present a waste product in the process of preparing copra. 



DESCRIPTION OP SAMPLE. 



The sample of the " water " measured two gallons and consisted of a thin, 

 slightly opalescent liquid which had a strong odour of chloroform, the latter having 

 been added to prevent fermentation during transit. 



CHEMICAL EXAMINATION. 



The composition of the water was determined in the Scientific and Technical 

 Department of the Imperial Institute with the following results :— 



Saccharine constituents : 



Mannitol ... ... ... 1"8 per cent (approximately). 



Cane Sugar ... ... ... 0"1 ,, ,, 



Glucose ... ... ... 0*9 ,, ,, 



Acid constituents : 



Volatile acid (calculated as acetic acid) ... 0'07 ,, ,, 



Non-volatile acid (calculated as tartaric acid) 0'41 ,, ,, 

 Mineral matter : 



(Ash) .. ... ... 0-50 „ „ 



Water ... ... ... 96'00 „ 



There are a number of previous analyses of coconut " water " on record, with 

 which the foregoing results may be compared. According to J. Lepine ("All 

 about Coconut Planting," A. M. and J. Ferguson, Colombo, 1904), Bizio has 

 stated that the "water" and the kernel of the coconut "contain no sugar 

 but mannitol." Lepine does not give a reference to Bizio's paper in which this 

 statement occurs, and consequently it has been impossible to verify it. Two 

 papers by Bizio on the subject of the composition of coconut " water" are published 

 in the Ann. Sci. Lomb. Veneto (iii, 1833, pp. 1-16 and pp. 107-120,) but in these there is 

 no reference to mannitol, the only sweet constituent found being a substance, 

 which is named " Glycina," and the reactions of this are not identical with those 

 of mannitol. According to Lepine (loc. cit.) the sugar present in both the kernel 

 and the water of the coconut is ordinary cane-sugar. 



More recently Van Slyke {American Chemical Journal, 1891, 13, pp. 130-131) 

 has found 3*9 per cent of glucose and a trace of cane sugar in the " water" of unripe 

 coconuts, and 4*42 percent of cane sugar and a trace of glucose in the "water "of 

 ripe nuts, whence it would appear that during the ripening process, the glucose 

 in the coconut " water " is largely converted into cane sugar. Van Slyke found 

 no mannitol in the " water " from either ripe or unripe nuts. 



