engleski

Rheological and thermo physical properties of ice cream model mixtures with reduced fat content

In ice-cream, fats have important function – stabilization of structure and achievement of desirable texture and melting characteristics. However, due to their impact on human health, consumers are demanding ice-cream with reduced fat content, but unchanged organoleptic properties. Reduction of fat content due to production of low-calorie products necessitates application of additives which prevent negative changes that occur due to reduction of fat content in product. For this purpose, different hydrocolloids and modified starches, among others, are used today. The aim of this research was to investigate the effect of addition of carrageenan, native tapioca starch and powdered whey on viscosity and thermo physical properties of model ice-cream mixtures with reduced fat content. Experiments are carried out by reducing fat for 30 % and adding carrageenan, native tapioca starch and powdered whey. Rotational viscometer DV-III+ Digital Rheometer-Brookfield Engineering Laboratories was used for measuring rheological properties at temperatures of 10, 5, 0 and -5 °C, and Differential Scanning Calorimeter DSC 822e-Mettler Toledo was used for measuring thermo physical properties. Measurements were done immediately after mixture preparation and after two-month-storage at -18°C. Results showed that reduction of fat content and addition of starch and whey increased value of rheological parameters, particularly at low temperatures (0 and -5 °C). After two month storage rheological parameters of all investigated samples increased. Freeze- and thaw-temperatures did not change significantly during storage. On the other hand, enthalpies of freezing and thawing changed considerably (in most cases decreased) after storage.

low calorie ice cream; rheological properties; thermo physical properties

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