Removal of color and turbidity in sugarcane juice treated by electrocoagulation with aluminum electrodes

Abstract

The liming (Ca(OH)2 addition) and sulfitation (HSO3- addition) is the conventional treatment for purification of sugarcane juice (SCJ) in sugar cane mills to crystal sugar production. Although, the sulfite has been associated to human health problems, this industrial step kept untouchable or few studies have been made to change this scenery. This work aimed to evaluate the variables which influence the electrocoagulation performance on the SCJ purification as a sulfur-free crystal sugar process. A fractional factorial design with the surface response methodology was used to evaluate the influence of voltage, pH, soluble solids total (Brix), temperature and distance between the electrodes in the electrocoagulation process. The outputs were turbidity, juice color, sucrose contents (as pol%juice) and Reducing Sugars (RS). Residual aluminum was analyzed by voltammetry to control de aluminum releasing into the treated juice. The electrocoagulation reduced color and turbidity, in special at low pH (2.5), highest voltage (25 V) and minimal distance of electrode (1.0 cm). Although in this conditions, sucrose was converted into RS indicating partial hydrolysis. In this work, the most part of residual aluminum went to floated and precipitated phases (76.8% and 18.1%, respectively), whereas only 5.1% remained in the SCJ clarified. Electrocoagulation/electroflotation proved to be a potential technique as a substitute for sulfitation in SJC treatment, which ensures the production of safe food for humans.

Mechanism elucidation of color formation in sugarcane juice during enzymatic

“…Sugarcane is a biological complex from the Poaceae kingdom, widely spread worldwide and focus of many studies, in particular for seletive breeding to increase productivity, pests and diseases resistance, susceptibility to drought (Cursi et al, 2022), but few are dedicated to understanding the enzymatic processes in the sugarcane juice browning and their impact on the white sugar quality. Our group has been studying ways to coloration reduction of sugarcane juice (Ogando et al, 2021;Magri et al, 2019), but had not yet tried to understand the mechanisms that cause the coloration formation. We also reported on the environmental conditions that promote color formation in sugar during storage (Aguiar et al, 2015).…”