FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY




Effect of microwave irradiation on rheological properties of starch hydrolysate solutions showing different degree of depolymerization


The objective of this study was to assess the impact of microwave irradiation on rheological properties of potato maltodextrin solutions showing different saccharification degree. The investigation material constituted commercial potato hydrolysates with three degrees of depolymerization and a laboratory maltodextrin of a middle degree of saccharification. The maltodextrins studied were used to make solutions, which were analyzed using a rotational rheometer. Flow curves at 50 °C were plotted as were curves determining the relation between viscosity and temperature in the range from 20 to 60 °C. In order to describe flow curves, Herschel-Bulkley and Newton models were applied, and Arrhenius model was used to determine the parameters of viscosity-temperature curves. The analyses accomplished proved that the physical modification of maltodextrins contributed to a change in the values of rheological parameters of solutions made thereof. The impact of a 440 W microwave irradiation on the potato hydrolysates with a medium and high degree of depolimerization caused the decrease in numerical values of dynamic viscosity coefficient. The increased microwave irradiation power to 800 W caused this parameter to increase, too, except for a commercial, medium saccharified maltodextrin. On the other hand, the temperature characteristic of viscosity of preparations made of medium and highly saccharified starch hydrolisates did not change after their microwave irradiation.


maltodextrins, rheological properties, physical modification of maltodextrins