engleski

Influence of adding sugars, modified starches and hydrocolloids on the termophysical properties of raspberry puree

The knowledge of the thermophysical properties is the fundament for describing and simulating thermal processes, such as heating, cooling, drying, freezing etc. Raspberry puree is semi - product which is a base for production of many raspberry products. The objective of this study was to investigate influence of adding sugars (sucrose, fructose, trehalose) , modified starches (Textra, Frigex W) and hydrocolloids (guar gum, gum karaya) on termophysical properties of raspberry puree. Thermophysical measurements of raspberry puree were carried out on the temperature from +25 till -30 ˚C with cooling speed of 5 ˚C/min and from -30 till +30 ˚C with heating speed of 5 ˚C/min. Thermophysical measurements were conducted with the differential scanning calorimeter (DSC), Mettler - Toledo DSC model 822e. The results of the research indicate that the lowest temperature was achieved by adding Textra and sugars sucrose and fructose. The lowest enthalpy of freezing and difrosting has puree with added Frigex W and sucrose and the highest has puree with added guar gum, sucrose and trehalose.

raspberry puree; sugars; modified starche; hydrocolloids; the thermophysical properties; freezing; thawing

nije evidentirano