Calcium phosphate flocs and the clarification of sugar cane juice from whole of crop harvesting

Thai, Caroline C. D., Moghaddam, Lalehvash, & Doherty, William O.S. (2015) Calcium phosphate flocs and the clarification of sugar cane juice from whole of crop harvesting. Journal of Agricultural and Food Chemistry, 63(5), pp. 1573-1581.

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Sugar cane biomass is one of the most viable feedstocks for the production of renewable fuels and chemicals. Therefore, processing the whole of crop (WC) (i.e., stalk and trash, instead of stalk only) will increase the amount of available biomass for this purpose. However, effective clarification of juice expressed from WC for raw sugar manufacture is a major challenge because of the amounts and types of non-sucrose impurities (e.g., polysaccharides, inorganics, proteins, etc.) present. Calcium phosphate flocs are important during sugar cane juice clarification because they are responsible for the removal of impurities. Therefore, to gain a better understanding of the role of calcium phosphate flocs during the juice clarification process,the effects of impurities on the physicochemical properties of calcium phosphate flocs were examined using small-angle laser light scattering technique, attenuated total reflectance Fourier transformed infrared spectroscopy, and X-ray powder diffraction. Results on synthetic sugar juice solutions showed that the presence of SiO2 and Na+ ions affected floc size and floc structure. Starch and phosphate ions did not affect the floc structure; however, the former reduced the floc size, whereas the latter increased the floc size. The study revealed that high levels of Na+ ions would negatively affect the clarification process the most, as they would reduce the amount of suspended particles trapped by the flocs. A complementary study on prepared WC juice using cold and cold/intermediate liming techniques was conducted. The study demonstrated that, in comparison to the one-stage (i.e., conventional) clarification process, a two-stage clarification process using cold liming removed more polysaccharides (≤19%),proteins (≤82%), phosphorus (≤53%), and SiO2 (≤23%) in WC juice but increased Ca2+ (≤136%) and sulfur (≤200%)

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ID Code: 87378
Item Type: Journal Article
Refereed: Yes
Keywords: whole of cane harvesting, trash, tops, stalk, sugar cane juice, clarification, calcium phosphate
DOI: 10.1021/jf502229f
ISSN: 0021-8561
Divisions: Current > Schools > School of Chemistry, Physics & Mechanical Engineering
Current > Research Centres > Centre for Tropical Crops and Biocommodities
Current > Institutes > Institute for Future Environments
Current > QUT Faculties and Divisions > Science & Engineering Faculty
  • SRDC/2011000730
Copyright Owner: Copyright 2015 American Chemical Society
Copyright Statement: This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Agricultural and Food Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see
Deposited On: 11 Sep 2015 00:41
Last Modified: 16 Feb 2016 02:26

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