International Topical Meeting on Nuclear Research Applications and Utilization of Accelerators

4-8 May 2009, Vienna
SM/EB-15

Effect of Electron Beam in Viscosity Properties of Inverted Liquid Sugar

P. Podadera and S.F. Sabato

IPEN – CNEN/SP, Sao Paulo, Brazil

Corresponding Author: sfsabato@ipen.br

The great advantage of inverted liquid sugar in food and pharmaceutical industries related to powder sugar is its sweetness once its main composition is a mixture of sucrose, glucose and fructose. Samples of this raw material were submitted to irradiation by an accelerator type Dynamitron-job 188, from Radiation Dynamics, Inc, at IPEN. The samples were delivered in Petri dishes with 3 mm thickness. The samples have received the following absorbed dose from the middle-energy of 1.44 MeV electron beam: 5 kGy and 10 kGy (current of 2.74 mA and dose rate of 11.19 kGy/s); 20 kGy, 30 kGy and 50 kGy (current of 5.48 mA and dose rate of 22.39 kGy/s). Viscosities were measured in a Brookfiled rheometer, model LV–DVIII, spindle SC4–34, at temperature 24.6±.0.1 °C.

Results confirmed the Newtonian rheological behavior of inverted liquid sugar for irradiated and control samples. Viscosity varied from 2799±15 cP (for control) to 2918±16 cP (for 50 kGy). Irradiated samples at 5 kGy and 10 kGy presented lower values than control, being respectively 2507±18 cP, that could represent a potential break of sugar molecules. Indeed, irradiation can lead to a breakage of molecules of sucrose with release of glucose and fructose and still, the break of this monosaccharide with formation of compounds containing chains of six or less carbons. Samples irradiated at 20 kGy and 30 kGy presented viscosities close to the control ones. Samples irradiated at the higher dose obtained the highest viscosity average (2918±16 cP), that could show a possible grade of polymerization.

This latter became with an intense color after irradiation. Anyway, the alterations due to irradiation were lower than the viscosity range encountered in different batches of sugar. This indicates that irradiation by electron beam did not impair the rheological properties that are essential in designing pumps, valves and equipments for processing facilities.