396 



The Philippine Journal of Science 

 Table XIV. — Available granulated sugar in nipa juice. 



1913 



Purity. 



Avail- 

 able i 

 sugar. 



Purity. 



Avail- 

 able 

 sugrar. 





Per c»nt. 





Per cent. 



80 



60 



86 



72 



81 



62 



87 



74 



82 



64 



88 



76 



83 



66 



89 



78 



84 



68 



90 



80 



85 



70 







For example, 1,000 liters of juice with a purity of 83.1, Brix 

 of 16.8, and sucrose content of 14 per cent would amount to 

 1,069 kilograms of juice with 179.6 kilograms of dry substance. 

 From the above table of extraction, 66 per cent, or 118.5 kilo- 

 grams, of granulated sugar could be obtained from this juice 

 without making any allowance for loss. This represents an ex- 

 traction of 11.1 per cent. The filter press and unknown loss 

 should not exceed 0.5 per cent, leaving 10.6 per cent, or 113 

 kilograms of sugar per 1,000 liters of juice. 



SUMMARY 



Yield of nipa sap. — Nipa palms produce about 40 liters of sap 

 per tree during an average season. A conservative estimate of 

 producing palms may be placed at 750 per hectare, yielding 

 30,000 liters of juice. The nipa district in the Provinces of 

 Bulacan and Pampanga alone is estimated to contain 18,000 

 hectares, and many other large areas in various islands are 

 available for sugar manufacture. 



Season of flow. — The average season during which sap is avail- 

 able in sufficient quantities to supply a sugar mill covers 

 approximately six months. The daily collections reach a 

 maximum during the second month, and gradually diminish 

 after the third or fourth month. 



Quality of sap. — The average nipa sap as it flows from the 

 palm during the season contains about 15 per cent sucrose, and 

 has an apparent purity of not less than 85. Invert sugar is 

 present only in traces. About 0.5 per cent of sodium chloride 

 slightly reduces the purity without lowering the extraction of 

 sugar, as it is classed among the nonmelassigenic salts. Waxes, 

 acids, pectins, and other foreign material are practically absent. 

 The sap contains active enzymes of the invertase and peroxidase 

 types, the latter being present only during the final period of 



