FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY

Authors

KAROLINA KRAMEK, PAWEŁ GLIBOWSKI

Title

Textural and rheological properties of mixtures of inulin and milk fat stabilized by lecithin

Abstract

The objective of the research study was to compare the textural and rheological properties of emulsions produced on the basis of milk fat (15, 20 %), inulin (15, 18, 21, 24 %), and soya lecithin (2 %). The emulsions were prepared by making inulin suspensions in water, heating them to a temperature of 65 or 100 °C, and by mixing them with anhydrous milk fat of a temperature of 70 °C fat, and with lecithin. Next, the mixtures were homogenized and the finished emulsions were stored at a temperature of 5 °C for 24 hours. After that time, rheological and textural properties were determined. Both the textural (hardness, adhesiveness, cohesiveness, and spreadability) and rheological properties (apparent viscosity, G’ and G” moduli) of the emulsions produced depended, to a significant degree, on the temperature of heating the inulin suspension. The analyzed properties of the mixtures prepared with the use of inulin suspensions heated to a temperature of 65 °C were characterized by a significantly lower standard deviation compared to those heated to a temperature of 100 °C. A probable reason thereof was that inulin lost its crystallization ability when it was wholly dissolved at 100 °C. The presence of milk fat did not catalyse the crystallization of inulin. At a lower temperature, it was possible for a homogenous emulsion to form. It was confirmed that the increase in the concentration of inulin and milk fat caused the hardness of emulsion to increase and its spreadability to decrease. Furthermore, it was found that in order to obtain the emulsion showing foreseeable textural and rheological properties, it was necessary to apply temperatures allowing the crystallisation of inulin.

Keywords

inulin, milk fat, emulsions, spreadability, textural properties, rheological properties

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