Vol. VII. No. 167. 



THE AGRICULTURAL NEWS. 



291 



SUGAR INDUSTRY. 



Sugar Production in Java. 



A statistical article dealing with sugar produotion 

 iii'Java was lately contributed to the Louisiana I'Lan- 

 ter by Dr. H. C. Prinsen Geerligs, Director of the 

 Agricultural Experiment Stations in the island. 



In 1898 the sugar-cane area of .J<i,va was 198,500 acres. 

 To-day it is 285,289 acres, 'j'lie number of sugar estates, 

 however, which was 188 ten years agn, has fallen to 177 at the 

 present time. This is owing to the prevalent tendency for 

 tlie amalgamati(jn of small estates, and to the development 

 of the central factory system. The sugar industry is very 

 profitable in the island, and many estate owners are anxious 

 to pmrchase more land, but this' cannot be done without 

 peri:ii.ssion from the OoveruTnent, who will not jjermit exten- 

 sion of the sugar-cane area unless it. can V>e done without 

 [)rejudiee to the re(|uirements of the native rice-growing 

 population. On the othei- hand, man)' estates on which 

 indigo was formerly cultivated have latterly become sugar 

 plantations. 



The output of sugar has rapidly advanced with the 

 extension in the cane acreage. The total yield of sugar ten 

 years ago was 725,030 tons, while the 1907 crop reached 

 1,210,197 tons. During the same period the average yield of 

 .sugar-cane per acre advanced from 'MQ tons to .38"75 tons. 

 Yields of sugar ranging from 4 9 tons to o-" tons per acre 

 have been obtained on the best sstates in the island each 

 year since 1898. 



Enzymes of the Sugar-cane. 



Enzymes are chemical cutiipounds usuall\' known as 

 unorsfanized or soluble t'eraients, in contradistinction to 

 the yeasts, bacteria, etc., which are referred to as organi- 

 zed ferments. These enzymes occur naturally in 

 various parts of the tissue of plants, being secreted by 

 the protoplasm, and they are associated with various vital 



.processes of the plant, especially those of nutrition. They 

 have the power, when in contact with certain substances, 

 of causing these substances to decompose into simpler 

 compounds. Diastase is one of the best known among 

 the enzymes. It occurs in leaves, buds, and in seeds, 

 and possesses the power of converting insoluble starch 

 into maltose, which is a soluble sugar. Reserve food 

 material is frequently stored up by plants in seeds 

 and tubers in the form of starch, as in maize and potatos, 

 and the function of the diastase present in the seetl or 

 tuber is to convert the starch into a soluble form, so that 

 in this state it is available for the heeds of the embryo 

 plant produced from the seed or tuber. 



The following notes on enzymes present in the 

 sugar-cane are taken from BaUrtin f)/ of the Louisiana 

 Agricultural Experiment Station, 'The Chemistry of 

 the Sugar-cane and its products in Louisiana ' : — 



Enzymes, or soluble ferments, although [iresent in 

 exceedingly .small amounts in the sugar-cane, play a very 

 important role in the physiological ]iroces.ses of the plant, and 

 re<piire more than a passing mention. If the green tops of 

 a sugar-cane be well nun-ei-ated, the juice expressed and 

 treated with an antiseptic agent, such as chloroform or thymol, 



' in oi-der to prevent fermentatif>n by yeasts or bacteria, it will 

 he found that the sucrose content of the juice undergoes 



a gradual diminution, though no traces of micro-organic life 

 are evident, and that sinudtaneously with this decrea.se in suc- 

 rose, the content fif reducing sugars, i.e., of glucose and fructose 

 increases. This is a well-marked instance of the activity of the 

 enzyme or soluble ferment invertdxc, which is present in the leaf 

 of the cane. This enzyme occurs almost universally through- 

 out the vegetable kingdom, especially ui the green or growing 

 parts of the plants. Invertase has a very practicsil industrial 

 bearing outside of its physiological importance. The 

 gradual falling off in .sucrose content of a .sugar-cane which 

 has been cut and kept for any length of time is due very 

 largely to the spontaneous inversion (or conversion into glucose 

 and fructose) of the sucro.se, caused by this ferment. If the 

 green tops of the cane are removed at the time of cutting, the 

 loss of sucrose is nuich less evident. This can easily be seen by 

 reference to the experiments carried on at Audubon Park in 

 1893, in which several lots of cane were cut and laid up, 

 and one-half of each lot had the tops removed, while the tops 

 were left in the case of the other half. Otherwise, all the 

 conditions were the same, and at the end of the month the 

 tops of the second half of the canes in each lot were nMuoved. 

 In the first lot, the canes, the green tops of which had been 

 removed a month before analysis of the juice took place, 

 showed a sucrose content of 13'3 per cent., and a glucose 

 content of 1 -25 per cent. The second half of the canes of 

 this lot, which h;id been cut and kept for a month with the 

 cane tops remaining on, contained at the end of the month 

 but 12'1 per cent, of sucrose (a decrea.se of 1'2 per cent.), 

 while the jtercentage of glucose reached 1"85 per cent. 



In a second test the percentage of sucrose present at the 

 end of the month, in canes laid up with the tops remaining on, 

 was 11;8, as compared with 13'7 per cent, in the other half 

 of the lot, where the growing tops had been removed at the 

 beginning of the month. While the sucrose content had 

 decreased from 137 to 11 '8 per cent, where the cane tops had 

 been left on, the percentage of glucose increased considerably, as 

 is evident from the fact that while only 1 per cent, of glucose 

 was [present in the canes the tops of which had been removed, 

 the percentage of glucose was 1 85 where the tops remained 

 on. It will be .seen therefore, that the inverting enzyme occurs 

 in chief i)art in the growing tops of the cane. Inversion of 

 the sucrose results in an increase in the glucose content, 

 though tliis incL-ease is not proportional to the loss of sucrose 

 content. This discrepancy is probably due to the destruction 

 of the glucose as the result of respiratii.>n in the leaf. The 

 experiments show conclusively that the vital processes of the 

 cane go on, even after it has been cut. It must not be 

 forgotten that there is also a slow inversion of sucrose in 

 canes that are cut and laid up with the green tops removed. 



A marked pe('uliarity of sugar-cane juice, as of all 

 vegetable juices, is the I'apid ilarkening in colour which takes 

 place after expression. This darkening is nuich more 

 evident within the body of the cane, especially in the region 

 of the eyes and growing parts, and when its tissues are laid 

 open to the air. We have here an evidence of another 

 enzyme. This belongs to the class of oxydases, or ferments whose 

 activity results in oxidation of the substances with which 

 tliey are brought into contact. The intense bhu* colouration 

 wliich the tis.sues and juices of plants take on when treated 

 with tincture of guaiacum (a resin from the Lignum-vitae 

 tree) is ascribed to an oxydase or oxidizing ferment. The 

 decomposing action '.ihich plant extracts exercise upon hydro- 

 gen (leroxide has been similarly explained. .Juice from 

 sterilized canes show none of these reactions, on account 

 of the destruction of the enzyme by the high temperature to 

 which it has been submitted. 



