Influence of the selected factors on the liquid food density

Abstract

The density of materials can be used for assessing their quality. The density of food materials depends on temperature and is caused by thermal expansion during heating. The density of a material is defined as a ratio between the mass of the material and its volume at the same temperature. One of the most exact methods for measuring liquid density is the pycnometric method. Measurements of materials density could also be performed using hydrometers or densimeters, where the exact value of density can be discerned on the hydrometer scale or on the display of measurement devices. During our experiments, we used two methods of density determination: pycnometric method and determination by a densimeter Mettler Toledo DM 40. Measurements were performed in the approximate temperature range (0 - 30) °C. The effect of various parameters (such as temperature, fat content, alcohol content and short storing time) on the density of the material was analysed in this paper. A linear decreasing character was applied for temperature dependencies of the sample density in the measured temperature range. The highest fat content of milk caused the lowest density, whereas lower fat contents (less than 1.5 %) were not consistent with this proportion due to different amounts of proteins in the measured samples of milk. The effect of the alcohol content on density had to be investigated alongside the material composition (wine, whisky and piña colada). The density values obtained were a bit higher after a short storage period due to the water loss during storage.

Keywords

• density
• measurement
• liquid food
• affecting factors