Czech Journal of Food Sciences, 2009 (vol. 27), issue 3
Determination of free amino acids in cheeses from the Czech market
Ivana Kabelová, Markéta Dvořáková, Hana Čížková, Pavel Dostálek, Karel Melzoch
Czech J. Food Sci., 2009, 27(3):143-150 | DOI: 10.17221/1415-CJFS 
High performance liquid chromatography (HPLC) method with the pre-column derivatisation by AccQ*Tag agent and following determination of these derivates after their separation in reverse phase column followed by fluorescent detection was used for the determination of amino acids in cheeses. The contents of sixteen free amino acids in twenty five cheeses commercially available in the Czech Republic were measured. The total content of free amino acids in the studied cheeses varied in the range from 27 g/kg to 160 g/kg. Among individual amino acids, seven amino acids were more concentrated in all cheese samples and came from three distinctive taste groups:...
Influence of trehalose, glucose, fructose, and sucrose on gelatinisation and retrogradation of corn and tapioca starches
Jurislav Babić, Drago Šubarić, Bronislav Miličević, Durdica Ačkar, Mirela Kopjar, Nela Nedić Tiban
Czech J. Food Sci., 2009, 27(3):151-157 | DOI: 10.17221/31/2009-CJFS
The effects of trehalose, glucose, fructose, and sucrose on the gelatinisation and retrogradation properties of corn (CS) and tapioca (TS) starches were studied with differential scanning calorimetry (DSC). The results showed that the sugars affect gelatinisation and retrogradation of both starches, with the effect varying significantly between sugars. The addition of trehalose, glucose, fructose, and sucrose increased the gelatinisation temperatures and enthalpy of gelatinisation of corn and tapioca starches. The extent of increase followed the order: fructose < glucose < trehalose < sucrose with CS, and fructose < trehalose < sucrose...
The effect of the barley variety, location and year crop on the haze of congress wort
Vratislav Psota, Zuzana Skulilová, Jiří Hartmann
Czech J. Food Sci., 2009, 27(3):158-164 | DOI: 10.17221/156/2008-CJFS
The study set consisted of eleven barley (Hordeum vulgare L.) varieties grown at four different locations for a three-year period. The malting characteristics were determined in all samples. The results obtained using the traditional visual evaluation of wort clarity were compared with those obtained nephelometerically. The results indicate a considerable effect of a variety on the wort haze (30-40%). The effect of location on the wort haze varied from 13-22%, the effect of year was small. The level of wort haze or wort clarity split the set of the varieties under study to clearly distinguishable groups. The worts from the varieties Annabell...
Textural and flavour characteristics of commercial tomato ketchups
Zdeňka Panovská, Petr Štern, Alena Váchová, Dobromila Lukešová, Jan Pokorný
Czech J. Food Sci., 2009, 27(3):165-170 | DOI: 10.17221/220/2008-CJFS
A set of 20 samples of tomato ketchup purchased on the market were analysed by several rheological procedures (Rheo-Stress 300) and by sensory profiling of both textural and flavour characteristics. A great variance was observed of all characteristics in all sample variables. About a third of plots between two variables were significantly related in the case of two rheological attributes and two sensory attributes, and in that of combinations between rheological and a sensory attributes. Similarly as in the case of lipid dispersions, the sensory texture acceptability was significantly related to the overall flavour acceptability. This proves the importance...
Influence of drying procedure on colour and rehydration characteristic of wild asparagus
Stela Jokić, Ibrahim Mujić, Milan Martinov, Darko Velić, Mate Bilić, Jasmina Lukinac
Czech J. Food Sci., 2009, 27(3):171-177 | DOI: 10.17221/149/2008-CJFS
The objective of this research was to examine the influence of different drying procedures on the colour quality and rehydration capacity of wild asparagus (Asparagus maritimus L.). Wild asparagus samples were dried using convective (40°C, 50°C, 60°C, and 70°C at the airflow velocity of 2.75 m/s), natural, and freeze (-20°C and -40°C) drying procedures. Rehydration and colour characteristics were used as indicators of the quality of the dried asparagus samples. Convective drying of asparagus resulted in the smallest colour change of the fresh material, whereby drying at 60°C presented the optimum. The best rehydration ratio was achieved when...
Variations in chemical compositions of Rosa damascena Mill. and Rosa canina L. fruits
Soner Kazaz, Hasan Baydar, Sabri Erbas
Czech J. Food Sci., 2009, 27(3):178-184 | DOI: 10.17221/5/2009-CJFS
In this study, fruits, fruit flesh and seeds of damask rose (Rosa damascena Mill.) and rose hip (Rosa canina L.) were assayed for the composition of fatty acids, ascorbic acid, α-tocopherol, β-carotene, and mineral elements. The content of linoleic acid in seed oil of Rosa damascena (54.18%) was found to be higher than in that of Rosa canina (48.84%). α-Tocopherol contents were found to be 7.10 μg/g and 34.20 μg/g for Rosa damascena and Rosa canina fruits, respectively. Ascorbic acid content was determined as the highest in the fruit flesh (546 mg/100 g in Rosa damascena...
Determination of antagonistic starter cultures for pickle and olive fermentation processes
Ahmet Hilmi Çon, Nihat Karasu
Czech J. Food Sci., 2009, 27(3):185-193 | DOI: 10.17221/86/2008-CJFS
In the present study, the main purpose was the selection of antagonistic starter cultures for pickle and olive fermentation processes. The chemical and microbiological properties of fermented 70 pickle and 16 olive samples collected from the province of the west part of Turkey were analysed. Subsequently, lactic acid bacteria strains producing bacteriocin-like metabolites were isolated and identified. From 86 samples, 16 isolates were chosen, depending on their partial antimicrobial activity against at least one selected indicator. 13 out of this 16 isolates were identified as Lactobacillus plantarum whereas 3 of them proved to be Lactobacillus...
Distribution of non-tuberculosis mycobacteria in environmental samples from a slaughterhouse and in raw and processed meats
Monika Morávková, Marija Kaevska, Neysan Donnelly, Ivo PAVLÍK
Czech J. Food Sci., 2009, 27(3):194-202 | DOI: 10.17221/120/2008-CJFS
The notification of all cases of diagnosed bovine tuberculosis is a statutory requirement, while the same is not true for other mycobacterial infections. Thus, the establishment of the true incidence of infection with non-tuberculous mycobacteria (NTM) is difficult. The aim of this study was to describe the incidence of NTM in environmental samples from a pig slaughterhouse and from raw and processed meat samples collected from supermarkets and butchers. Three species of mycobacteria (M. chelonae, M. kansasii, and M. intermedium) were detected in 8.0% of the environmental samples from a pig slaughterhouse and in 9.3% of raw and...
The use of Bacillus subtilis for screening fusaric acid production by Fusarium spp.
Antónia Šrobárová, Štefan EGED, Jaime TEIXEIRA DA SILVA, Alberto Ritieni, Antonello Santini
Czech J. Food Sci., 2009, 27(3):203-209 | DOI: 10.17221/64/2008-CJFS
Fusaric acid (FA) is one of the most important secondary metabolites produced by Fusarium oxysporum (Schlecht) (FO), F. solani (Mart.) Appel & Wollenweber, and F. moniliforme Sheldon. It is toxic to humans, many plants, and microorganisms and it enhances the toxicity of fumonisin and trichothecene. A simple and rapid method for fusaric acid (FA) screening in Fusarium isolates was developed. In this study, several strains of Fusarium oxysporum were tested for their ability to produce FA by using a suitable race of Bacillus subtilis as the bioassay. A modified method using small agar blocks with the fungus...
Forecasting the necessity of grain fumigation during storage
Dimitar KUZMANOV, Nikolay DIMITROV
Czech J. Food Sci., 2009, 27(3):210-215 | DOI: 10.17221/2654-CJFS
According to the simulation models composed for the population growth and feeding damage of the insects: Sitophilus oryzae (L.), Sitophilus granarius (L.) and Rhizopertha dominica (F.) the populations densities have been determined at which the grain fumigation costs at using phosphorus hydrogen preparations equal the damage values caused by insects. The necessity of fumigation can be forecasted, according to the population growth time up to these limits. For this purpose, simulation models at temperatures of 21, 24, 27, and 30°C have been used. The products of time and temperature should be calculated at different temperatures...
Tissue distribution and elimination of florfenicol in topmouth culter (Culter alburnus) after oral administration
Weifen WANG, Xianjun DAI, Zhiqiang LI, Qingli MENG
Czech J. Food Sci., 2009, 27(3):214-221 | DOI: 10.17221/183/2008-CJFS
The serum concentration and muscle residue of florfenicol following oral administration were evaluated in topmouth culter (Culter alburnus) under field conditions. Fishes were cultured in tanks and fed a commercial medicated diet containing 2000 mg/kg florfenicol in a single dose. The sampling was conducted at different intervals (0, 0.5, 1, 1.5, 2, 3, 4, 8, 10, 12, 16, 24, 36, 48, 72, 96, 120, 144, 168 h) after the cessation of medication. Drug analysis was carried out by HPLC. The maximum concentration (Cmax) of 10.8 μg/g in serum and 4.2 μg/g in muscle were reached at the same time (tmax) of 8 hours....