Color reduction of raw sugar syrup using hydrogen peroxide

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 mgH2O2 L-1), # 13 (pH=7.5; 83.6°C and 500 mgH2O2 L-1) and #15 (pH= 7.5; 50°C and 1.000 mgH2O2 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 mgH2O2 L-1), although sucrose degradation of 26% was observed.

Volatile aroma composition of distillates produced from fermented sweet and acid whey

Lactose within whey can be fermented and distilled to produce a potable distilled spirit. The aim of this study was to determine if acid and sweet whey types can be fermented and distilled using similar processes and to investigate differences in volatile aroma compounds for the 2 distillates. Fermentation and distillation of the 2 whey types progressed in a similar manner, using Kluyveromyces marxianus for the initial fermentation and a glass still fitted with a Vigreux column for the subsequent distillation. Ethanol content of the wash (fermented whey) varied considerably following each fermentation and ranged from 1.2 and 2.0% (wt/wt) with no clear trend between acid and sweet whey samples. Volatile aroma compounds were extracted using headspace solid-phase microextraction and identified via gas chromatography-mass spectrometry. Acid and sweet whey distillates contained unique volatile aromatic compounds, and significant differences in compound peak areas were observed. These differences may have an effect upon the organoleptic qualities of spirits produced from whey; therefore, whey source may be an important factor when fermenting and distilling whey.