| Popis: |
Sugar is an essential food powder used in great quantities in households and food industry. Besides providing a sweet taste to food products, it is also responsible for prevention of microbial growth and texture enhancement. In industry surroundings, problems arise during conveying of sugars, especially sucrose, due to its particle size, shape, moisture and glass transition properties. From food safety aspect, it is important to monitor these properties throughout industrial handling of sucrose in order to stop a possible microbial contamination, dusting and production process stoppage. In this research, commercially available sucrose crystals were ground and different particle size fractions were collected using conventional sieving analysis. Obtained fractions were analysed as follows: median particle diameter was determined using laser diffraction particle sizing, bulk density was determined by jolting volumeter method and flow properties (cohesiveness, caking properties and changes in compaction behaviour with different conveying speeds) was determined by the powder rheometer method using Powder Flow Analyser (Stable Micro Systems, UK). Fractions obtained by sieving were in particle size range from 800 µm to 50 µm. Fractions of particle sizes below 200 µm started to exhibit flow difficulties - increased cohesion index and stronger susceptibility to caking. Mathematical correlation between particle sizes, bulk densities, cohesion and caking properties was also defined using Eureqa Formulize software package (Nutonian, USA). Crystalline form of sucrose showed different behaviour at different flow speeds in comparison with pulverized fractions, and proved to be more suitable for industry purposes. |
