Abstract: The paper deals with the following topics: - importance of food physics - physical methods in instrumental food analysis - physical techniques in modern food processing - main topics in BSc level education, concerning basic physics, general and inorganic chemistry, electrotechnics, measurement technique and automation - main topics in MSc level education, concerning instrumental food analysis, food physics, process control, measurement theory, research planning
Keywords: BSc, food engineer, food science, MSc, physics, technology, university education
Abstract: The aims of this present study were the determination of electrical conductivity and mineral content of different honey types and the examination of the relation among the floral origin, electrical conductivity and element content. Electrical conductivity and 13 elements (K, Ca, Mg, Na, P, S, Al, B, Ba, Cu, Fe, Mn and Zn) were determined with digital conductivity meter and ICP-OES) in seven honey types (acacia, lime, silk grass, sunflower, rape, chestnut and forest). The values of the electrical conductivity ranged between 0.101 and 1.036 mS/cm. The lowest values were measured in the acacia, silk grass and rape honey samples and the chestnut and forest honey samples showed the highest values. The electrical conductivity showed strong correlation with K, Mg and S (r = 0.975, 0.856 and 0.802). It was possible to determine the botanical origin of the case of the lime and sunflower honey types was able to determine by measuring their electrical conductivity.
Keywords: electrical conductivity, honey, botanical origin
Abstract: According to Codex Alimentarius (2004) honey is a natural sweet substance, produced by honeybees from the nectar of plants or from secretions of living parts of plants, or excretions of plant-sucking insects on the living parts of plants, which the bees collect, transform by combining with specific substances of their own, deposit, dehydrate, store and leave in honeycombs to ripen and mature. Physical properties of honey are influenced by many factors and most important of them are temperature, time of storage, honey composition, mixture of flowers visited by bees producing the honey and it differs with locations, terms and particular colony of bees. In our research we focused on influence of temperature and time of storage to rheologic properties of forest honey.
Keywords: forest honey, rheological properties on temperature, dynamic and kinematic viscosity, viscometer Anton Paar
Abstract: The viscosity of supersaturated aqueous glucose-fructose solutions has been measured, using flow curves on an Anton Paar RheolabQC rotating viscometer. Three different concentration (85%, 83%, 81%) and five different glucose:fructose ratios (60:40, 55:45, 50:50, 45:55, 40:60) has been selected in a similar composition to honey. Measurements were taken at temperatures ranging from +10 to +50 °C. All systems exhibited Newtonian behaviour, meaning that the viscosity is independent of the shear rate. The viscosity of the supersaturated solutions was decreasing with increasing temperature and increasing with increasing the concentration. Aqueous solutions of fructose are somewhat more viscous than glucose solutions. For aqueous glucose-fructose solutions, the increase of fructose concentration increases the solutions viscosity.
Keywords: supersaturation, glucose, fructose, viscosity
Abstract: Beer is a well-known fermented beverage, which is a complex mixture of more than 800 compounds. Thanks to the raw materials, beer is an excellent source of different valuable components such as polyphenols, which influence the colours of beers. In our research the colour values and total polyphenol contents of our self-brewed beers were determined and the results were compared with the colours of commercial beers. Based on our result it can be stated that there is moderately correlation between the polyphenol content and colour value.
Keywords: beer, colour, total polyphenol content, correlation