Physico-chemical Characterization of Turbidity-Causing Particles in Beet Sugar Solutions

Abstract

The occurrence of turbidity is a frequently observed phenomenon in beet sugar manufacturing, particularly in thick juice. The presence of small dispersed turbidity-causing particles can have a direct impact on the consumer’s perceivable quality of white sugar containing products. Therefore, this work aims to characterize those turbidity-causing particles and elucidate the mechanism of their formation. Samples from various European beet sugar plants were collected during different sugar production periods. The turbidity of white sugar is found to be mainly related to small calcium oxalate particles (0.45–1 µm). Their occurrence is obviously related to the presence of calcium and oxalate. However, the analysis presented documents that beyond the levels of these ions, other factors like storage time, the change of environment due to microbiological processes as well as simple processing steps have a profound effect on turbidity levels. The results confirm that also at an industrial scale calcium oxalate dihydrate precipitates from concentrated sucrose solutions despite the fact that calcium oxalate monohydrate is the most stable form. In summary our analysis of turbidity at an industrial scale marks a starting point for any further turbidity reduction approach.

Soluble Asian sea bass bone bio‐calcium: characteristics, bioavailability across Caco‐2 cells and fortification into apple juice

“…(2005) reported that higher turbidity was observed in organic acid solution with higher calcium concentration. Higher turbidity was also found in beet sugar solution when calcium oxalate was fortified at a higher concentration (Abdel‐Rahman & Floeter, 2016).…”

Modelling of cross‐flow microfiltration coupled with bentonite treatment in sugar beet molasses purification

“…In the SMP mode, turbidity reduction was significantly lower (Table , Figure b). Insoluble compounds generated during the sugar production process, mainly calcium salts (sulphate, oxalate dihydrate, and oxalate mono‐hydrate) with a size range of 1–6 µm and smaller, along with the colloidal components originating from the plant are recognized as turbidity‐causing particles in sugar solutions . Since the majority of the non‐sugar compounds are lagging behind in molasses, the concentration of turbidity‐causing particles in molasses is increased.…”

Limitations of turbidity process probes and formazine as their calibration standard

“…Furthermore, their processing is often performed at high concentrations of the dispersed phase. A common approach to monitor the process state is implementing a turbidity or optical density probe [3–9]. These probes are, reputedly, easy to use and financially attractive.…”