Relationships were established for five sensory methods of oral and nonoral viscosity evaluation between viscosity scores and instrumentally measured dynamic viscosity for model and real Newtonian fluid foods. These relationships were then used to predict the effective shear rates under which the sensory tests were performed. The highest shear rates were predicted for viscosity perception by compression of samples between tongue and palate, and the lowest for pouring the fluid foods from a teaspoon. Mixing with a teaspoon, slurping and swallowing exhibited nearly the same dependencies of apparent shear rates on equivalent instrumental viscosity. All relations were of the hyperbolic type. The resulting relationships between the apprent shear rates and equivalent instrumental viscosity are in good agreement with a similar relationship predicted by Shama and Sherman (1973a) (see Cutler et al. 1983) for oral perception.

A method is described here for the simultaneous determination of retinol,α-tocopherol, lycopene, andβ-carotene in human plasma. The effectiveness of various protein precipitants and extraction solvents was tested. After adequate sample preparation, the samples were injected directly into the HPLC system. The separation was realized on an analytical reversed-phase column with a UV-Vis detection. The analytical performance of this method was satisfactory. The intraassay and interassay coefficients of variation were below 10%. The recoveries were as follows: 97.0% (CV 2.4%) for retinol, 94.6% (CV 1.7%) forα-tocopherol, 91.9% (CV 3.6%) for lycopene, and 93.9% (CV 4.2%) forβ-carotene. The levels of selected fat-soluble vitamins in plasma of patients with cardiovascular disease were measured and discussed.

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Totušek J., Tříska J., Lefnerová D., Strohalm J., Vrchotová N., Zendulka O., Průchová J., Chaloupková J., Novotná P., Houška M. (2011): Contents of sulforaphane and total isothiocyanates, antimutagenic activity, and inhibition of clastogenicity in pulp juices from cruciferous plants. Czech J. Food Sci., 29: 548-556.The consumption of Cruciferous vegetables is important for the prevention of cancerous diseases, particularly colorectal cancer. The effects of technological treatments (freezing, pasteurisation, high-pressure treatment) on the content of isothiocyanates, considered to be the active substance, were observed in single-species vegetable juices prepared from cruciferous vegetables (broccoli, cauliflower, Brussels sprouts, white and red cabbage). The contents of sulforaphane and total isothiocyanates were studied relative to the temperature, action period, and time delay after juice pressing. Sulforaphane and total isothiocyanates were determined by HPLC. Sulforaphane content in various parts of fresh broccoli was also assessed. Antimutagenic activity of the juices (frozen, pasteurised, and high-pressure treated) was evaluated using the Ames test and the following mutagens: AFTB1 (aflatoxin B1), IQ (2-amino-3-methyl-3H-imidazo-[4,5-f]quinoline), and MNU (2-nitroso-2-methylurea). Clastogenicity inhibition of the mutagens, in response to broccoli juice, as well as of pure sulforaphane, was observed using an in vivo experiment (the micronucleus test). It was shown that in terms of sulforaphane content, it is best to let broccoli juice stand for 60 min after pressing and pH adjustment. Sulforaphane content does not change under heating to 60°C. Its content decreases considerably (compared to fresh juice) with heating to higher temperatures than 60°C. High-pressure treatment preserves mutagenic inhibition to the same degree as juices freezing.

The goal of this work was to provide evidence for the inhibitory effects of fresh hops on the growth of Helicobacter pylori. Fresh hops were homogenised after harvest and the homogenate was treated using pascalisation (treatment with high pressure). This homogenate was used for testing the growth inhibitory effects on strains of H. pylori, a pathogenic microorganism, isolated from patients suffering from gastritis or gastric ulcers. The tests demonstrated reliable inhibitory effects and open the possibility of hops being used as a supplement to the treatment of H. pylori infections.