Color reduction of raw sugar syrup using hydrogen peroxide

Redução de cor em xarope de açúcar bruto usando peróxido de hidrogênio

Abstract

A commercial H₂O₂ solution (35%, v/v) was evaluated as a clarifying agent for raw, type VHP (very high polarization) sugar syrup, using an experimental design applying artificial neural networks (ANN). Fifteen experimental runs were carried out and the samples were taken at the following time intervals: 0, 5, 10, 15, 20, 25, 30, 40, 50, 60, 75 and 90 min. The treatments were carried out using an experimental design consisting of three variables: H₂O₂ (X1: 0; 202.4; 500; 797.6 and 1.000 mg L^-1); pH (X2: 3.32, 5, 7.5, 10 and 11.68) and temperature (X3: 16.4, 30, 50, 70 and 83.6°C). The theoretical and measured values fitted the analysis by artificial neural networks (ANN) well. A reduction in colour (ICUMSA method) was observed between 60 and 75 min, except for treatments # 11 (pH= 11.68; 50°C and 500 mg_H2O2 L^-1), # 13 (pH=7.5; 83.6°C and 500 mg_H2O2 L^-1) and #15 (pH= 7.5; 50°C and 1.000 mg_H2O2 L^-1), which showed a colour reduction after 30 min. In the treatments at pH 3.32 or 11.68, temperature of 83.6°C and H₂O₂ dose of 1.000 mg L^-1, an average sucrose degradation of 55% was observed. The best colour reduction result was obtained with treatment # 9 (pH 7.5, 50 °C and 500 mg_H2O2 L^-1), although sucrose degradation of 26% was observed.

Keywords:
Clarification; Oxidation; Sucrose; Reduction; Kinetics; Degradation