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PROGRESS REPORT ON THE USE OF NATIVE 

 SUGARS FOR PRESERVES. 



By H. H. Cousins, M.A., F.C.S., Island Chemist. 



This subject was considered to be of importance to the sugar 

 industry of Jamaica and the Sugar Department is engaged on an 

 investigation of the matter. The following results have been 

 already obtained : — 



Sajnples of Sugars. 



Brown and White Vacuum Pan Sugars were obtained from mer- 

 chants and sugar planters, as follows : — 



Sugars. 

 Estate. Description. Polarisation, 



I 



Belleisle White 98.9 



Brown 98.2 



Caymanas White 99.0 



' Yellow Demerara' 96.9 



Per Messrs. Myers White 98.6 



Per Messrs. Wray & Nephew Brown 96.1 



Cinnamon Hill Brown 98.6 



Do. Fair 99.8 



Serge Island Brown 98.4 



Worthy Park Brown 99.3 



These data are very creditable to our Jamaica Sugars. The 

 sugars from Cinnamon Hill and Worthy Park were of unusual 

 purity and nearly chemical sucrose. Some of the other sugars 

 were somewhat damp and moist. We have, regularly produced in 

 the island, a supply of sugars well fitted for preserving if properly 

 sterilised. We found, however, that all these sugars were more or 

 less infected with a species of Tonila with a powerful fermentive 

 action. All these sugars rapidly developed this organism when in- 

 troduced into sterile nutritive media, even in the proportion of 

 equal parts sugar and medium. This shows that unless perfectly 

 sterilised, the native sugars could not successfully be used for pre- 

 serving in the usual proportion of half sugar to half fruit. 



Experhnefits in Sterilisation and zvith Preservatives. 



Neither Boric Acid nor Formaldehyde, within the limits at all per- 

 missible in a food product, were effective in preserving fruit pulp. 

 Sulphur Dioxide, however, proved strikingly effective and it was 

 decided to select this preservative as the best and least harmful 

 agent for preserving fruit pulp and jams. 



Provided sterile conditions could be maintained in the contain- 

 ing vessel, steaming proved completely effective in preserving both 

 pulps and jams made with native sugar. 



It was found, however, under commercial conditions of pack- 

 ing, that marmalades made with native sugars fermented. By 

 adding^ per cent. Calcium Bisulphite solution of specific gravity 1. 068 



