Presence of Dextran and It’s Negative Effects on Cane Sugar Production in Sudan

Abstract

The research objective is to study of the effects of different cane conditions in the field on dextran level in cane juice (e.g. burning, chopping, delay between cutting and milling, and type of ratoon), and factors affecting levels of dextran during processing. The most important five criteria vis: polarization (pol), apparent purity, pH, viscosity and commercial cane sugar (C.C.S) of the cane juice besides dextran content of juice have been used to measure the cane deterioration. At the field level the results show that dextran formation was greater in chopped than long cane. Also the rate of deterioration of burnt cane is significantly higher than of green cane, with burnt chopped cane deterioration more rapid and extensive than in green chopped cane for the three types of cane; plantation, 1st ratoon, and 2nd ratoon. This was concomitant with a decrease in each of pol, apparent purity, pH, C.C.S, and an increase in viscosity which can be very good indicators to cane deterioration. Sugar losses from 11% - 50% were observed during the delay time to four days on the different cane samples. IV At the factory level the highest dextran was in mixed juice and decreased considerably during the process of sugar production. The greatest amount of dextran entering the factory goes to final molasses while only small amount goes to sugar. The dextran content correlated strongly with decreasing each of Brix, pol and apparent purity of most factory samples, and very strongly with decreasing of C.C.S, pH values and increasing of viscosity for all factory samples, which can be very good indicators to dextran presence during processing. Statistical analyses showed that for every 100 ppm of dextran in cane juice, there is an average sucrose loss of 0.4 Kg /ton cane. So molasses purities have augmented to reach values as high as 43 %. Dextran removal percentage reaches up to 61.97 % during the clarification of juice, and this increased to 74.01% with application of biocide. Mill sanitation in turn decreased dextran content by about 58 %, and then each 0.05 % or (500 ppm) reduction in dextran content in the juice will result in a savings of 2 kg of sugar/ton of sugar produced. For data of “Algunied” cane sugar factory would potentially recover 0.97 ton additional sugar/ day. With regard of process chemical costs, and for a 220 day crop recovers 213.4 tons at SDG 2008.00 / ton sugar, the gain is SDG 408892 / year.