Sugar beet molasses purification by bentonite addition: Analysis of quality enhancement and treatment conditions

Abstract

© 2018 Elsevier Ltd Reduction of non-sugar compounds in sugar beet molasses through various treatments is a promising method for molasses quality enhancement, improved sugar recovery and prevention of possible changes during storage. The presented study was conducted in order to examine the effect of sodium and calcium bentonite treatment on sugar beet molasses colour, turbidity and unavoidable sucrose content reduction during the purification process. Box-Behnken experimental design was employed with 3 independent parameters: pH (3–7), molasses dry substance (30–50° Brix) and bentonite suspension concentration (9–21 g/L) while treatment temperature was constant (60 °C) in all conducted experiments. Lower pH values and increasing bentonite concentrations expressed positive influence on molasses colour and turbidity reduction. Corresponding parameters also had slightly negative impact on molasses sucrose content. Compared to the calcium bentonite, sodium bentonite exhibited better results in terms of molasses colour and turbidity reduction. Optimal treatment parameters for achieving a 29–39% reduction in colour and 91–98% in turbidity with minimal sucrose content reduction (5%) were: pH 5.11–5.17, molasses dry substance 38.5–40.3° Brix and bentonite concentration 16–21 g/L.