Czech Journal of Food Sciences, 2015 (vol. 33), issue 2
ESBL-producing bacteria and MRSA isolated from poultry and turkey products imported from ItalyFood Microbiology and Safety
Chiara BENINATI, Felix REICH, Daniele MUSCOLINO, Filippo GIARRATANA, Antonio PANEBIANCO, Günter KLEIN, Viktoria ATANASSOVA
Czech J. Food Sci., 2015, 33(2):97-102 | DOI: 10.17221/428/2014-CJFS 
ESBL and MRSA-producing bacteria in food-producing animals may contribute to increased incidences of infection in humans. This study was carried out on 38 samples obtained from 32 chickens and 6 turkey products purchased at retail outlets of Hannover (Germany) and imported from Italy. The samples included the thigh, breast fillet, gizzard, sausage, liver, heart, and roll, and were processed for the detection of ESBL producing E. coli and MRSA producing Staphylococcus aureus. Twenty-six chicken products (68.4%) of the total of poultry products analysed proved to be positive for E. coli and for phenotypical detection of ESBL....
Kinetic analysis of anthocyanin degradation and polymeric colour formation in grape juice during heatingFood Chemistry
Gülşan DANIŞMAN, Esra ARSLAN, Ayşegül Kirca TOKLUCU
Czech J. Food Sci., 2015, 33(2):103-108 | DOI: 10.17221/446/2014-CJFS
The degradation of total monomeric anthocyanins and changes in the proportion of polymeric colour (% PC) as well as antioxidant capacity of grape juice were studied during heating at 70-90°C. Anthocyanin degradation fitted to a first order reaction model, while the formation of % PC followed zero order reaction kinetics. High correlations (r = 0.989-0.997) were found between anthocyanin degradation and % PC formation during heating. The activation energies for the degradation of anthocyanins and formation of % PC were 64.89 and 50.42 kJ/mol, respectively. Trolox equivalents antioxidant capacity (TEAC) values of grape juice slightly changed during heating.
Characterisation of polyphenol oxidase and peroxidase and the role in browning of loquat fruitFood Chemistry
Xinglong ZHANG, Xingfeng SHAO
Czech J. Food Sci., 2015, 33(2):109-117 | DOI: 10.17221/384/2014-CJFS
Polyphenol oxidase (PPO) and peroxidase (POD) were extracted from a new loquat fruit cultivar (Ninghaibai) and characterised using reliable spectrophotometric methods. In both cases, the optimum pH for PPO was 4.5 and 5 for POD, and their optimum temperatures were 30 and 35°C, respectively. Both enzymes followed Michaelis-Menten kinetics, showing Km= 47.11 mmol/l for PPO with catechol as the substrate and Km = 153.00 mmol/l for POD with guaiacol as the substrate. PPO was much more thermolabile than POD, losing more than 40% of relative activity after 30 min of heating at 40°C. PPO activation energy was much lower...
Development of innovative health beneficial bread using a fermented fibre-glucan productFood Analysis, Food Quality and Nutrition
Lenka BLAŽEKOVÁ, Petra POLAKOVIČOVÁ, Lucia MIKUŠOVÁ, Kristína KUKUROVÁ, Vojtech SAXA, Zuzana CIESAROVÁ, Ernest ŠTURDÍK
Czech J. Food Sci., 2015, 33(2):118-125 | DOI: 10.17221/42/2014-CJFS
The impact of partial substitution of fine wholemeal oat flour by fermented oat sourdough in wheat-oat bread formula on the basic bread constituents and organoleptic properties, and to assess wheat-oat breads from the qualitative and nutritional point was find. Fermentation of sourdough from a special finewholemeal oat flour fraction was optimised using potentially probiotic lactic acid bacteria Lactobacillus plantarum which resulted in 1010 CFU/gof vital bacterial cells and 2.95 g/l of lactic acid content. Wholemeal oat sourdough was characterised by stable gel consistency suitable for its technological application as a starter...
Phenolic content and antioxidant capacity of Cypriot winesFood Analysis, Food Quality and Nutrition
Charis M. GALANAKIS, Anestis KOTANIDIS, Maria DIANELLOU, Vassilis GEKAS
Czech J. Food Sci., 2015, 33(2):126-136 | DOI: 10.17221/335/2014-CJFS
We characterised 12 wines (10 red, 1 sweet red, and 1 white) from different Cypriot cultivars in terms of their phenolic, anthocyanin composition, and antioxidant capacity as determined by two activities: radical scavenging and ferric reducing ability. Two different phenolic fractions (tannin-free and 1-kDa permeate) were also isolated from Cypriot wines with an ultimate goal of investigating their role in the overall antioxidant capacity of wines. The results indicated that Maratheftiko and Lefkada cultivars had higher concentrations of o-diphenols, hydroxycinnamic acid derivatives, flavonols and anthocyanins compared to other Cypriot cultivars...
Chemometric classification of citrus juices of Moroccan cultivars by infrared spectroscopyFood Analysis, Food Quality and Nutrition
Aziz HIRRI, Michele DE LUCA, Giuseppina IOELE, Abdessamad BALOUKI, El Mahfoud El BASSBASI, Fouzia KZAIBER, Abdelkhalek OUSSAMA, Gaetano RAGNO
Czech J. Food Sci., 2015, 33(2):137-142 | DOI: 10.17221/284/2014-CJFS
Fourier transform - infrared (FTIR) spectroscopy in connection with chemometric methodologies was used as a fast and direct analytical approach to classify citrus cultivars by the measurements on their juice. Modern multivariate analysis responds to the current needs for economic, simple, and fast methods able to classify new unknown samples with great accuracy. A set of 135 samples of citrus juice, representative of three cultivars (Hamlin, Muska, and Valencia), all picked in the same geographical area of Morocco, were analysed. Chemometric discrimination of the juice samples was achieved by principal component analysis (PCA) performed on the FTIR...
Quantification of parvalbumin in commercially important Mediterranean seafood species using real time PCRFood Analysis, Food Quality and Nutrition
Dimitra HOUHOULA, Polytimi DIMITRIOU, Gena MENGJEZI, Vasiliki KYRANA, Vladimiros LOUGOVOIS
Czech J. Food Sci., 2015, 33(2):143-147 | DOI: 10.17221/390/2014-CJFS
The parvalbumin allergen gene was quantified in various types of seafood using RT PCR. Freshly harvested specimens from 25 species of finfish, molluscs, and crustacean shellfish, commonly consumed in the Mediterranean region, were included in the investigation. DNA was extracted using the commercial NucleoSpin Food kit. The amplification of the parvalbumin gene was performed by RT PCR. Sixteen out of the 25 species examined yielded positive amplification. Positive samples, including several species of fish (Atlantic mackerel, horse mackerel, sheepshead, red mullet, sandsmelt, pandora, saddled sea bream, gilthead sea bream, red sea bream, European sea...
Characterisation of hop varieties grown in Romania based on their contents of bitter acids by HPLC in combination with chemometrics approachFood Analysis, Food Quality and Nutrition
Liana-Claudia SALANŢĂ, Maria TOFANĂ, Sonia SOCACI, Elena MUDURA, Anca FĂRCAŞ, Carmen POP, Anamaria POP, Antonia ODAGIU
Czech J. Food Sci., 2015, 33(2):148-155 | DOI: 10.17221/365/2014-CJFS
Reverse-phase high performance liquid chromatography technique was used for studying the evolution of bitter acids from three varieties of hop growing in Romania during the development of hop cones and the pelletisation process in order to provide the information on the bitter acids profile of each cultivar. Chemometrics methods were applied for highlighting the statistical correlations existing between the genotype (variety), chemotype (composition), and phenotype (phenophase of cone development) with respect to the classes of biologically active compounds investigated (bitter acids). The bitter acid content of each hop cultivar was not only significantly...
Mineral profile of Croatian honey and differences due to its geographical originFood Analysis, Food Quality and Nutrition
Natalija URŠULIN-TRSTENJAK, Davor LEVANIĆ, Ljiljana PRIMORAC, Jasna BOŠNIR, Nada VAHČIĆ, Goran ŠARIĆ
Czech J. Food Sci., 2015, 33(2):156-164 | DOI: 10.17221/502/2014-CJFS
The proportions of twelve minerals were determined in 200 samples of the black locust honey from five Croatian regions during two seasons. The average proportions were dominated by that of K (205.57-428.05 mg/kg), followed by Ca (33.53-329.00 mg/kg) and Na (23.34-218.04mg/kg), which was in percentages as follows: K 31.69-81.34%, Ca 6.51-35.56%, and Na 7.36-23.65%. Melissopalynological and physico-chemical analysis of honey confirmed its general quality requirements and botanical origin. One-factor analysis of variance showed a significant differences between the regions in each season based on the average proportions of macro and micro elements except...
Quality control of chondroitin sulphate used in dietary supplementsFood Analysis, Food Quality and Nutrition
Eliška VÁCLAVÍKOVÁ, František KVASNIČKA
Czech J. Food Sci., 2015, 33(2):165-173 | DOI: 10.17221/326/2014-CJFS
Chondroitin sulphate (CS), a complex polysaccharide isolated from animal cartilage, is used as an ingredient in dietary supplements to support joint health and/or to treat osteoarthritis. Several low-quality CS raw materials were identified in marketed products of dietary supplements. For the evaluation of the quality of CS, we present here a capillary isotachophoretic method (cITP). As a leading electrolyte for the anionic analysis of CS, a mixture of 5 mM HCl + 10 mM glycine + 0.01% of 2-hydroxyethylcellulose of pH 2.8 was used. A solution of 10 mM citric acid served as the terminating electrolyte. On a series of CS raw material samples we proved...
Validation of hydrogen cyanide fumigation in flourmills to control the confused flour beetleFood Technology and Economy, Engineering and Physical Properties
Radek AULICKY, Vaclav STEJSKAL, Milan DLOUHY, Jana LISKOVA
Czech J. Food Sci., 2015, 33(2):174-179 | DOI: 10.17221/303/2014-CJFS
In the milling industry, the Tribolium confusum is hard to exterminate pest. We measured the concentration time product (Ct-P) achieved during the hydrogen cyanide (HCN) fumigation and examined whether the Ct-P levels in the explored Czech pilot mill were sufficient to control the field strain of T. confusum. Using an originally constructed, gastight fumigation chamber, it was estimated that the Ct-P required for the complete killing of the field strain of T. confusum was 4× higher (4.35 g/h/m3) than the levels required to kill the laboratory strain (1.25 g/h/m3). The Ct-P levels (ranging from 79 g/h/m3...
Physico-chemical and sensory properties of bread enriched with lemon pomace fiberFood Technology and Economy, Engineering and Physical Properties
Rei-Chu CHANG, Chia-Yen LI, Sy-Yu SHIAU
Czech J. Food Sci., 2015, 33(2):180-185 | DOI: 10.17221/496/2014-CJFS
Lemon fiber (LF) was extracted from lemon pomace and incorporated into bread. The results showed that the hardness of bread increased with the increase of LF substitution (0-9%), but the cohesiveness, springiness, and specific volume decreased with the fiber substitution. Both Peleg-Normand and Wiechert models fitted well the stress relaxation data of bread. The parameters (k1 and k2, as well as P0-P2 and λ2) in two models were followed significantly affected by the amount of LF. The breads enriched with LF revealed higher total phenolic contents and DPPH radical scavenging capacities than the control bread. Compared with water, methanol was...
Cassava roots: perspectives of a traditional staple for bio-solvents productionFood Technology and Economy, Engineering and Physical Properties
Touré Marouf SIDI SÉIBOU, Mojmír RYCHTERA, Karel MELZOCH
Czech J. Food Sci., 2015, 33(2):186-194 | DOI: 10.17221/447/2014-CJFS
The culture media prepared from mashed cassava and cassava starch were used to test their convertibility into organic solvents such as acetone, butanol, and ethanol. The trials were conducted in Erlenmeyer flasks containing various culture media with initial starch concentrations ranging from 30 g/l to 100 g/l. Fermentation was carried out by Clostridium acetobutylicum DSM 1731. The purpose of these tests was to determine the initial starch concentration which could be used as a starting point for the fermentation in laboratory bioreactors. In this case, we used two culture media: the first one made with cassava starch (M1), and the second one with...