Czech Journal of Food Sciences, 2016 (vol. 34), issue 3
Microbiological quality of raw milk in the Czech RepublicFood Microbiology and Safety
Kateřina Bogdanovičová, Marcela Vyletělová-Klimešová, Vladimír Babák, Libor Kalhotka, Ivana Koláčková, Renáta Karpíšková
Czech J. Food Sci., 2016, 34(3):189-196 | DOI: 10.17221/25/2016-CJFS 
The microbiological and hygienic quality of cow's, goat's and sheep's milk in the Czech Republic was evaluated. Milk (230 samples) was collected on 41 farms and investigated from May 2012 to October 2014. Milk was analysed for the presence of selected groups and types of bacteria: mesophilic microorganisms (total plate count - TPC), enterococci, Enterobacteriaceae, Escherichia coli, Staphylococcus aureus, Salmonella spp., Campylobacter spp., and Listeria monocytogenes. Besides these indicators and pathogenic agents, somatic cell count was determined as one of the indicators of mammary gland health...
Antibacterial characteristics of orange pigment extracted from Monascus pigments against Escherichia coliFood Microbiology and Safety
Guo-Ping Zhao, Ying-Qiu Li, Jie Yang, Kai-Yu Cui
Czech J. Food Sci., 2016, 34(3):197-203 | DOI: 10.17221/430/2015-CJFS
The antibacterial characteristics of orange pigment, which is one of the Monascus pigments, against Escherichia coli were investigated. Orange pigment exhibited strong antibacterial activity against E. coli evidenced by an increase in the diameter of inhibition zone with orange pigment treatment. The concentration of 2.5 mg/ml was the minimum inhibitory concentration of orange pigment against E. coli. Scanning electron microscopy revealed that orange pigment could damage bacterial cells, eventually resulting in cell death. The increase in the electric conductivity of bacterial cell suspensions suggested that the...
Biofilm formation by Pseudomonas aeruginosa and disinfectant susceptibility of planktonic and biofilm cellsFood Microbiology and Safety
Magdalena A. Olszewska, Aleksandra M. Kocot, Aleksandra Stanowicka, Łucja Łaniewska-Trokenheim
Czech J. Food Sci., 2016, 34(3):204-210 | DOI: 10.17221/528/2015-CJFS
Epifluorescence microscopy (EFM) was used to study the biofilm formation of Pseudomonas aeruginosa after 6, 24, 30, 48, 54, 72, 78, and 96 h growth in a chamber slide system. For this purpose, the biofilm was stained with the Live/Dead BacLight, wherein live and dead cells were visualised based on the cell membrane integrity. With the use of EFM we described 8- of 9-stage biofilm characteristics after 78 h of growth, since the majority of microscopic fields were fully covered with attached cells. However, the 96-h growth resulted in the cell detachment and revealed 30% of dead cells of all those cells that remained on the surface. The susceptibility...
Content of polymerised triacylglycerols in fat of fried foodsFood Analysis, Food Quality and Nutrition
Liliya Mekhanoshina, Zuzana Réblová
Czech J. Food Sci., 2016, 34(3):211-216 | DOI: 10.17221/372/2015-CJFS
Polymerised triacylglycerols (TAG) were determined in the fat of 66 industrially produced fried foods (especially frozen pre-fried French fries, potato chips and other fried snacks) and 56 samples of French fries (and other forms of fried potatoes) prepared in restaurants, snack bars, and other catering establishments. All samples were purchased in the Czech Republic, especially in Prague, in the years 2012-2014. Polymerised TAG were determined by HP-SEC with refractive index detection, after the fat extraction with petroleum ether. While in none of the samples of industrially produced fried foods did the content of polymerised TAG in fat exceed the...
Phenolic content of honey reduces in vitro starch digestibilityFood Analysis, Food Quality and Nutrition
Javier Parada, Jose L. Santos, Paula Cañoles, Nimia Manquián
Czech J. Food Sci., 2016, 34(3):217-223 | DOI: 10.17221/304/2015-CJFS
The starch digestibility of foods containing honey, as a function of honey's phenolic content was evaluated. We have evaluated the in vitro digestibility of starch from potato when added to honey. Natural honey diminished the starch digestibility compared to simulated honey (0% phenolics). A negative correlation between starch digestibility and total phenolic content was found (samples grouped by the honey botanical origin): for rapidly available glucose R2 was 0.76, whereas for unavailable glucose R2 was 0.89. Our results suggest a possible beneficial capacity of phenolic contents present in honey to...
Detection of adulteration in freshly squeezed orange juice by electronic nose and infrared spectroscopyFood Analysis, Food Quality and Nutrition
Fei Shen, Qifang Wu, Anxiang Su, Peian Tang, Xiaolong Shao, Bing Liu
Czech J. Food Sci., 2016, 34(3):224-232 | DOI: 10.17221/303/2015-CJFS
The use of electronic nose and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) as rapid tools for detection of orange juice adulteration has been preliminarily investigated and compared. Freshly squeezed orange juices were tentatively adulterated with 100% concentrated orange juices at levels ranging from 0% to 30% (v/v). Then the E-nose response signals and FTIR spectra collected from samples were subjected to multivariate analysis by principal component analysis (PCA) and linear discriminant analysis (LDA). PCA indicated that authentic juices and adulterated ones could be approximately separated. For the classification...
Quantification of bee-derived peptide defensin-1 in honey by competitive enzyme-linked immunosorbent assay, a new approach in honey quality controlFood Analysis, Food Quality and Nutrition
Ivana Valachová, Marcela Bučeková, Juraj Majtán
Czech J. Food Sci., 2016, 34(3):233-243 | DOI: 10.17221/422/2015-CJFS
We established and evaluated a polyclonal antibody based competitive enzyme-linked immunosorbent assay for the quantification of defensin-1 in honey. The assay showed an inhibitory concentration (IC50) value of 111.5 ± 15.41 ng/ml with a detection limit of 7.8125 ng/ml. The regaining of defensin-1 in spiked 'artificial honey' was between 87.05 and 112.96% with relative standard deviation less than 9.2%. Sensitivity and specificity of the test were experimentally validated on a sample of 20 different honeys. The antibacterial activity of these honey samples showed a significant concentration-dependent correlation with the production...
Characterisation of phenolics and other quality parameters of different types of honeyFood Technology and Economy, Engineering and Physical Properties
Rostislav Halouzka, Petr Tarkowski, Sanja Ćavar Zeljković
Czech J. Food Sci., 2016, 34(3):244-253 | DOI: 10.17221/321/2015-CJFS
In order to provide a general picture of phytochemical characteristics of nectar honey, honeydew, and mixed honeys, an overall comparison of physicochemical parameters, and phenolic profile as well as antioxidant activity of various types of honey samples has been made. Among all samples analysed, honeydew samples possess the best quality parameters in the mean content of hydroxymethylfurfural, proline, and diastase activity. Moreover, the highest content of phenolic compounds as potential radical scavengers was found in honeydews, then in mixed and multifloral nectar honeys, while samples of monofloral honeys revealed the lowest, but still considerable...
Comparing phenolic composition of Cabernet Gernischet wines between rain-shelter cultivation and open-field cultivationFood Technology and Economy, Engineering and Physical Properties
Yan-Nan He, Peng-Fei Ning, Tai-Xin Yue, Zhen-Wen Zhang
Czech J. Food Sci., 2016, 34(3):254-270 | DOI: 10.17221/429/2015-CJFS
The phenolic compounds of Vitis vinifera cv. Cabernet Gernischet wine in 2010 and 2011 vintage from rain-shelter cultivation and open-field cultivation were detected and compared by high performance liquid chromatography coupled with diode array detector and electrospray ionisation mass spectrometry. The results showed that rain-shelter cultivation increased the total anthocyanin and non-anthocyanin phenolic compound concentration. For the compositions, ratios of peonidin-derivative and malvidin-derivative pigments were similar in the two vintages, rain-shelter cultivation increased the proportion of these derivatives; ratios of delphinidin-derivative...
The effect of wort filling time on fermentation, maturation and acetaldehyde content in beerFood Technology and Economy, Engineering and Physical Properties
Krzysztof KUCHARCZYK, Tadeusz TUSZYŃSKI
Czech J. Food Sci., 2016, 34(3):265-270 | DOI: 10.17221/469/2015-CJFS
The effect of wort filling time on the process of fermentation, maturation, and acetaldehyde content in beer was determined. The experiments were performed on an industrial scale, the fermentation and maturation took place in fermentation tanks. Three tanks were filled using three different intervals. Worts were aerated with sterile air and yeast was added after the second fermentation (third passage). During fermentation and maturation, changes in the content of the apparent extract and the amount of acetaldehyde were investigated. Experiments have shown that different filling times have a significant impact on the course of fermentation and the amount...
An analysis of milk fouling formed during heat treatment on a stainless steel surface with different degrees of roughnessFood Technology and Economy, Engineering and Physical Properties
Joanna Piepiórka-Stepuk, Katarzyna Tandecka, Marek Jakubowski
Czech J. Food Sci., 2016, 34(3):271-279 | DOI: 10.17221/466/2015-CJFS
Results of research on the effect of stainless steel (SS) surface roughness on the amount and microscopic structure of milk impurities, formed under the influence of high-temperature milk processing are presented. Three types of plates of different roughness were used in the study: Ra = 0.028 µm; Ra = 0.174 µm; Ra = 0.445 µm. The plates were immersed in raw milk and heated at 85-90°C for 30 min, imitating pasteurisation conditions. As a result of this action, a milk sediment difficult to remove was created. The structure of impurities was determined by the Confocal Scanning...