Stability of sugarcane juice – a preliminary assessment of the colorimetric method used for phosphate analysis

Abstract

This paper reviews the properties of sugarcane juice by summarizing the main chemical and physical reaction processes that occur during the clarification process. As the phosphate content in sugarcane juice is an important parameter in the clarification process, this paper also examines the current colorimetric method used for the determination of phosphate in sugarcane juice. In this method a phosphomolybdate blue complex is measured at 660 nm. At this wavelength the soluble inorganic phosphate content of juice can be underestimated by as much as 30%, due to interference of color in juice. It is recommended that the measurement should be carried out at the higher wavelength of 875 nm.