Czech Journal of Food Sciences, 2008 (vol. 26), issue 5
Biofilms and hygiene on dairy farms and in the dairy industry: sanitation chemical products and their effectiveness on biofilms - a review
Hana Vlková, Vladimír Babák, Růžena Seydlová, Ivo Pavlík, Jarmila Schlegelová
Czech J. Food Sci., 2008, 26(5):309-323 | DOI: 10.17221/1128-CJFS 
Microbial biofilms which form on all types of surfaces of technological systems in the dairy industry and on dairy farms adversely affect the quality and safety of final products, i.e. both foodstuffs and raw materials used for their production. The fact that a number of microorganisms are alimentary pathogens, e.g. Staphylococcus aureus or Listeria monocytogenes, makes a serious problem directly affecting human health. Biofilms are usually formed by various species of microorganism, which protect each other against the effects of biocidal (antibacterial) agents and are resistant to these agents. The colonisation of surfaces of the open...
Isolation of anticlostridially active lactobacilli from semi-hard cheese
Štěpán Tůma, Kateřina Kučerová, Milada Plocková
Czech J. Food Sci., 2008, 26(5):324-332 | DOI: 10.17221/115/2008-CJFS
The group of 7 strains of facultatively heterofermentative lactobacilli (FHL) of the non starter lactic acid bacteria (NSLAB) isolated from semi-hard cheeses using a well agar diffusion assay possessed a different level of inhibition activity against 16 different strains of Clostridium sp. belonging to the species Cl. butyricum, Cl. tyrobutyricum, Cl. beijerinckii, and Cl. sporogenes. Two selected strains with the production of partially indentified anticlostridially active inhibitory substances, Lb. paracasei ST68 (producing hydrogen peroxide) and Lb. paracasei 171R2 (producing bacteriocin and hydrogen peroxide),...
Stabilization of minced meat colour by carbon monoxide
Petr PIPEK, Ladislav STARUCH, Masatoshi IZUMIMOTO
Czech J. Food Sci., 2008, 26(5):333-338 | DOI: 10.17221/1130-CJFS
The effect of carbon monoxide was studied on the colour stabilisation of minced meat and on oxidation of lipids. The meat colour was evaluated using reflectance spectrophotometry and video image analysis (software LUCIA 5.20). Minced meat (beef and mixture of beef and pork) was packed under industrial conditions into three different modified atmospheres (MA) consisting of combinations of oxygen, carbon dioxide, carbon monoxide, and nitrogen. Carbon monoxide prevented the oxidation of lipids and haem pigments in minced meat and thus stabilised the red colour of minced meat. The redness a* of the meat packed under CO was constant during storage (nearly...
Optimised procedure to analyse Maillard reaction-associated fluorescence in cereal-based products
Cristina Delgado-Andrade, José A. Rufián-Henares, Francisco J. Morales
Czech J. Food Sci., 2008, 26(5):339-346 | DOI: 10.17221/39/2008-CJFS
Fluorescent Maillard compounds measurement provides more specific information on the extent of the Maillard reaction than other unspecific tools to monitor the reaction, and is suitable, as the first approach, to assess the nutritional quality of foods as related to protein damage. This work presents an optimised laboratory procedure for the measurement of total fluorescent intermediate compounds (FIC) associated with Maillard reaction, described and evaluated in a cereal-based product. Total FIC are evaluated using increased pronase E concentrations and different incubation times for the enzymatic hydrolysis, as well as three different sample clean-up...
Patatin, the major protein of potato (Solanum tuberosum L.) tubers, and its occurrence as genotype effect: processing versus table potatoes
Jan BÁRTA, Veronika BÁRTOVÁ
Czech J. Food Sci., 2008, 26(5):347-359 | DOI: 10.17221/27/2008-CJFS
Patatin relative abundance in SDS-extractable protein and patatin content in dry matter were evaluated in tubers of forty processing and table potato cultivars usually cultivated in the Czech Republic, Germany, and the Netherlands. The patatin characteristics were evaluated over three experimental years. Patatin relative abundance in the processing cultivars achieved on average a significantly higher value (P < 0.001; Tukey HSD test) than patatin relative abundance in the table cultivars, resulting in average values of 25.80% and 21.59%, respectively. A high patatin relative abundance (over 30% in extractable protein) was determined only...
Nondestructive identification of tea (Camellia sinensis L.) varieties using FT-NIR spectroscopy and pattern recognition
Quansheng Chen, Jiewen Zhao, Muhua Liu, Jianrong Cai
Czech J. Food Sci., 2008, 26(5):360-367 | DOI: 10.17221/1125-CJFS
Due to more and more tea varieties in the current tea market, rapid and accurate identification of tea (Camellia sinensis L.) varieties is crucial to the tea quality control. Fourier Transform Near-Infrared (FT-NIR) spectroscopy coupled with the pattern recognition was used to identify individual tea varieties as a rapid and non-invasive analytical tool in this work. Seven varieties of Chinese tea were studied in the experiment. Linear Discriminant Analysis (LDA) and Artificial Neural Network (ANN) were compared to construct the identification models based on Principal Component Analysis (PCA). The number of principal components factors (PCs)...
Assessment of the authenticity of fruit spirits by gas chromatography and stable isotope ratio analyses
Renata WINTEROVÁ, Renata MIKULÍKOVÁ, Jiří MAZÁČ, Pavel HAVELEC
Czech J. Food Sci., 2008, 26(5):368-375 | DOI: 10.17221/1610-CJFS
The gas chromatographic (GC) determination of volatile constituents and the determination of 13C/12C isotope ratios by isotope ratio mass spectrometry - IRMS analysis as well as SNIF-NMR analysis of (D/H)I and (D/H)II ratios in ethanol are prospective analytical methods which can be used for checking the authenticity of fruit spirits and for detecting their adulteration. Different concentrations of volatile compounds such as acetaldehyde, ethyl acetate, diethyl acetal, methanol, 1-butanol, 2-butanol, 1-propanol, 2-methyl-1-propanol, 2- and 3-methyl-1-butanol, volatile fatty acids and isotopic data were demonstrated using discriminant...
Influence of media composition and temperature on volatile aroma production by various wine yeast strains
Vlatka Petravić Tominac, Karin Kovačević Ganić, Draženka Komes, Leo Gracin, Mara Banović, Vladimir Marić
Czech J. Food Sci., 2008, 26(5):376-382 | DOI: 10.17221/11/2008-CJFS
Volatile aroma compounds production by two autochthonous Saccharomyces cerevisiae strains, isolated from Istria region, and three other yeast strains (Saccharomyces bayanus and two commercial Saccharomyces cerevisiae wine yeasts) was investigated on a small scale using synthetic VP4 medium and Graševina must at 12 and 20°C. The results obtained by gas chromatography analyses were compared with the aroma production properties of the native microflora, remaining after Graševina must sulphiting. In both media and at both temperatures, the wine yeasts investigated showed different metabolic profiles regarding the tested volatile aroma...
Microbiological quality of ice cream after HACCP implementation: a factory case study
Emmanuel N. Kokkinakis, Georgios A. Fragkiadakis, Souzana H. Ioakeimidi, Ilias B. Giankoulof, Aikaterini N. Kokkinaki
Czech J. Food Sci., 2008, 26(5):383-391 | DOI: 10.17221/1126-CJFS
The microbiological quality of the final product and the safety of the production procedures were screened in an ice cream factory, after implementation of a Hazard Analysis Critical Control Points (HACCP) system. We analysed 30 vanilla (IC1), 30 strawberry (IC2), and 30 chocolate flavoured (IC3) samples of ice cream; 30 of water; 90 of personnel's hands flora; 150 of plastic ice cream containers flora; 50 of sanitised equipment-surfaces flora. After HACCP introduction, Staphylococcus aureus was not further detectable in ice cream and Escherichia coli was mostly less than 10 CFU/g, while the spoilage markers (total coliforms - TC, aerobic plate counts...
Jan Velíšek, Karel Cejpek - Biosynthesis of Food Components
J. Davídek
Czech J. Food Sci., 2008, 26(5):392 | DOI: 10.17221/178/2008-CJFS