Template-Type: ReDIF-Article 1.0 Author-Name: Janka VRANOVÁ Author-Workplace-Name: Food Research Institute, Bratislava, Slovak Republic Author-Name: Zuzana CIESAROVÁ Author-Workplace-Name: Food Research Institute, Bratislava, Slovak Republic Title: Furan in food - a review Abstract: Furan and its derivatives were identified in a small number of heat-treated foods back in the 60's and 70's. In May 2004, US Food and Drug Administration published a report on the occurrence of parent furan in a number of thermally treated foods. Since furan has been classified as "possibly carcinogenic to human" by IARC, a great concern has been addressed to the analysis of this substance naturally-occurring in food. This paper gives a short overview on the mechanistic pathways of the parent furan formation in food by degradation of amino acids and/or reducing sugars, and oxidation of ascorbic acid and poly-unsaturated acids which can be induced by thermal or irradiation treatments; further, it deals with the metabolism and toxicology of furan as well as with the comparison of the methods of furan determination. Keywords: furan, heat processing contaminants, headspace, solid-phase microextraction, mechanisms of furan formation Journal: Czech Journal of Food Sciences Pages: 1-10 Volume: 27 Issue: 1 Year: 2009 DOI: 10.17221/2843-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/2843-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200901-0001.txt Handle: RePEc:caa:jnlcjf:v:27:y:2009:i:1:id:2843-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Matej POSPIECH Author-Workplace-Name: Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic Author-Name: Bohuslava TREMLOVÁ Author-Workplace-Name: Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic Author-Name: Eva RENČOVÁ Author-Workplace-Name: Veterinary Research Institute, Brno, Czech Republic Author-Name: Zdeňka RANDULOVÁ Author-Workplace-Name: Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic Title: Immunohistochemical detection of soya protein - optimisation and verification of the method Abstract: A functional immunohistochemical method for soya proteins detection was developed. The procedure is based on the avidin-biotin complex (ABC) method that attains sufficient sensitivity. The method was verified by the analysis of the model samples of different forms of soya additives containing various concentrations of soya isolate. The detection limit of soya present in the model samples was 0.5%. Different possibilities of the background staining were tested. The best results were obtained with the background staining according to Calleja. The results were confirmed by the accredited indirect ELISA method. The method allows the identification of various forms of soya proteins such as isolates, texturates, concentrates, and flour. Keywords: plant proteins, identification, model samples Journal: Czech Journal of Food Sciences Pages: 11-19 Volume: 27 Issue: 1 Year: 2009 DOI: 10.17221/2848-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/2848-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200901-0002.txt Handle: RePEc:caa:jnlcjf:v:27:y:2009:i:1:id:2848-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Mirela KOPJAR Author-Workplace-Name: Faculty of Food Technology, University of J. J. Strossmayer in Osijek, Osijek, Croatia Author-Name: Vlasta PILIŽOTA Author-Workplace-Name: Faculty of Food Technology, University of J. J. Strossmayer in Osijek, Osijek, Croatia Author-Name: Nela NEDIĆ TIBAN Author-Workplace-Name: Faculty of Food Technology, University of J. J. Strossmayer in Osijek, Osijek, Croatia Author-Name: Drago ŠUBARIĆ Author-Workplace-Name: Faculty of Food Technology, University of J. J. Strossmayer in Osijek, Osijek, Croatia Author-Name: Jurislav BABIĆ Author-Workplace-Name: Faculty of Food Technology, University of J. J. Strossmayer in Osijek, Osijek, Croatia Author-Name: Đurđica AČKAR Author-Workplace-Name: Faculty of Food Technology, University of J. J. Strossmayer in Osijek, Osijek, Croatia Author-Name: Maja SAJDL Author-Workplace-Name: Faculty of Food Technology, University of J. J. Strossmayer in Osijek, Osijek, Croatia Title: Strawberry jams: influence of different pectins on colour and textural properties Abstract: Colour and texture are very important quality properties of all foods. In this work, the influence was investigated of different types of pectin on colour and textural properties in strawberry jams and low-calorie strawberry jams containing fructose and aspartame or fructose syrup and aspartame. The highest anthocyanin content and total phenol content were detected in strawberry jam samples prepared with low methoxy amidated pectin. During storage, after 4 and 6 weeks at both storage temperatures, room temperature and 4°C, anthocyanin content and total phenol content decreased. Also, free radical scavenging activity decreased during storage. As far as the texture parameters are concerned, namely firmness, consistency and cohesiveness, the highest values were found in strawberry jam samples prepared with high methoxyl pectin. Keywords: pectin, strawberry jam, low-calorie strawberry jam, anthocyanins, texture Journal: Czech Journal of Food Sciences Pages: 20-28 Volume: 27 Issue: 1 Year: 2009 DOI: 10.17221/95/2008-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/95/2008-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200901-0003.txt Handle: RePEc:caa:jnlcjf:v:27:y:2009:i:1:id:95-2008-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Tomaž Požrl Author-Workplace-Name: Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana Jamnikarjeva, Ljubljana, Slovenia Author-Name: Mirela Kopjar Author-Workplace-Name: Faculty of Food Technology, Franje Kuhača, Osijek, Croatia Author-Name: Irena Kurent Author-Workplace-Name: ŽITO Prehrambena industrija d.d., Ljubljana, Slovenia Author-Name: Janez Hribar Author-Workplace-Name: Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana Jamnikarjeva, Ljubljana, Slovenia Author-Name: Anja Janeš Author-Workplace-Name: Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana Jamnikarjeva, Ljubljana, Slovenia Author-Name: Marjan Simčič Author-Workplace-Name: Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana Jamnikarjeva, Ljubljana, Slovenia Title: Phytate degradation during breadmaking: The influence of flour type and breadmaking procedures Abstract: Phytic acid has been considered to be an antinutrient due to its ability to bind minerals and proteins, either directly or indirectly, thus changing their solubility, functionality, absorption, and digestibility. In this study, the influence of the flour type (type 500, type 850, and whole meal flour) and three different breadmaking procedures (direct, indirect, and with sourdough addition) on phytic acid was investigated. The results showed that the flour type influenced the phytic acid content. The phytic acid contents of flour type 500, type 850, and whole meal flour was 0.4380, 0.5756, and 0.9460 g/100 g dm, respectively. The dough and bread prepared from flour with a higher phytic acid content also contained higher amount of phytic acid. During fermentation and baking, degradation of phytic acid occurred. Phytic acid was also influenced by pH. Samples of lower pH had a lower phytic acid content. Dough prepared from flour type 500 and type 850 with 10% addition of sourdough had especially low phytic acid contents, and the bread prepared from the respective dough contained no phytic acid at all. Keywords: phytic acid, flour type, breadmaking procedure Journal: Czech Journal of Food Sciences Pages: 29-38 Volume: 27 Issue: 1 Year: 2009 DOI: 10.17221/130/2008-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/130/2008-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200901-0004.txt Handle: RePEc:caa:jnlcjf:v:27:y:2009:i:1:id:130-2008-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Jan Polák Author-Workplace-Name: Department of Analytical Chemistry, Faculty of Engineering, Author-Name: Oto Mestek Author-Workplace-Name: Department of Analytical Chemistry, Faculty of Engineering, Author-Name: Richard Koplík Author-Workplace-Name: Department of Food Chemistry and Analysis and Author-Name: Jiří Šantrůček Author-Name: Jana Komínková Author-Workplace-Name: Department of Analytical Chemistry, Faculty of Engineering, Author-Name: Milan Kodíček Title: Trace elements species fractionation in rye flour and rye (Secale cereale L.) seedlings Abstract: The fractionation of Cd, Cu, Mo, Ni, and Zn species in extracts of rye (cv. Fernando) seedlings (grown up in both standard and Cd2+-enriched medium) and rye flour was performed by SEC/ICP-MS method. The majority of Cu, Zn, and Ni in all samples were bound in the 1-2 kDa fraction. Molybdenum occurred in all samples in the fraction of 3 kDa. During five days of cultivation in a solution of 30 µmol/l Cd2+, the plants accumulated as much as 5 mg/kg fresh matter of Cd, but its soluble portion represented only 12-15%. The prevailing portion of Cd complexes was contained in the fraction of 3 kDa, while the minor part occurred in the fraction of 20 kDa. The speciation of elevated Cd in plants differs from that of other metals present at a physiological level. The metal-rich fractions of the extracts of all samples (i.e. those of 1-2 kDa) were refined by immobilised metal affinity chromatography. The isolated ligands of trace elements were peptides rich in dicarboxylic aminoacids. Keywords: rye, metal, speciation, trace elements, MALDI-MS, ICP-MS, IMAC Journal: Czech Journal of Food Sciences Pages: 39-48 Volume: 27 Issue: 1 Year: 2009 DOI: 10.17221/33/2008-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/33/2008-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200901-0005.txt Handle: RePEc:caa:jnlcjf:v:27:y:2009:i:1:id:33-2008-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Xia Chen Author-Workplace-Name: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Huhhot, P.R.China Author-Name: Mei Yang Author-Workplace-Name: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Huhhot, P.R.China Author-Name: Zhihong Sun Author-Workplace-Name: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Huhhot, P.R.China Author-Name: Wenjun Liu Author-Workplace-Name: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Huhhot, P.R.China Author-Name: Tiansong Sun Author-Workplace-Name: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Huhhot, P.R.China Author-Name: He Meng Author-Workplace-Name: School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, P.R.China Author-Name: Heping Zhang Author-Workplace-Name: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Huhhot, P.R.China Title: Molecular cloning and characterisation of alpha subunit of H+-ATPase in Lactobacillus casei Zhang Abstract: The acid tolerance is an important property of Lactic acid bacteria as potential probiotics. H+-ATPase is considered a key gene in several bacteria with the ability of acid tolerance. We cloned and sequenced the full length cDNA of alpha subunit of H+-ATPase gene in Lactobacillus casei Zhang, which had been isolated from traditional home-made koumiss in Inner Mongolia of China. The results showed that the respective cDNA sequence is composed of 1530 nucleotides and codes a putative protein including 509 amino acids. In addition, we also reconstructed the phylogenic trees for H+-ATPase gene based on amino acids sequences of diverse strains of Lactic acid bacteria. Keywords: H+-ATPase, clone, sequence, Lactobacillus casei Zhang, phylogenic trees Journal: Czech Journal of Food Sciences Pages: 49-54 Volume: 27 Issue: 1 Year: 2009 DOI: 10.17221/134/2008-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/134/2008-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200901-0006.txt Handle: RePEc:caa:jnlcjf:v:27:y:2009:i:1:id:134-2008-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Pinar ŞANLIBABA Author-Workplace-Name: Kalecik High School, Ankara University, Kalecik, Ankara, Turkey Author-Name: Nefise AKKOÇ Author-Workplace-Name: Department of Biology, Faculty of Science, Ankara University, Tandogan, Ankara, Turkey Author-Name: Mustafa AKÇELIK Author-Workplace-Name: Department of Biology, Faculty of Science, Ankara University, Tandogan, Ankara, Turkey Title: Identification and characterisation of antimicrobial activity of nisin a produced by Lactococcus lactis subsp. lactis LL27 Abstract: In this study, bacteriocin producing lactococcal strains were isolated from Turkish raw milk samples. Among these isolates, LL27 had the highest inhibition activity against Gram-positive indicator strains, and was selected for further analyses. DNA sequencing of 16S ribosomal RNA gene demonstrated that the isolate was Lactococcus lactis subsp. lactis. The gene encoding the bacteriocin in this strain was found to be identical to that of nisin A using direct PCR sequence methods. The bacteriocin was completely inactivated by α-chymotrypsin and proteinase K and partially inactivated by lipase and α-amylase. pH and heat stability characteristics were found to be identical with those of the control nisin. The inhibitory activity of the bacteriocin produced by LL27 was also evaluated against Gram-negative bacteria in combination with heat and freezing treatments. The results obviously showed that the production level of nisin of the Lc. lactis LL27 had a significant inhibitory effect on the pathogenic Gram-negative strains with the heating and freezing processes which are commonly used in the food processing. Keywords: nisin A, Lactococcus lactis, sublethal injury, heating, freezing Journal: Czech Journal of Food Sciences Pages: 55-64 Volume: 27 Issue: 1 Year: 2009 DOI: 10.17221/151/2008-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/151/2008-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200901-0007.txt Handle: RePEc:caa:jnlcjf:v:27:y:2009:i:1:id:151-2008-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Elżbieta KLEWICKA Author-Workplace-Name: Institute of Fermentation Technology and Microbiology and Author-Name: Robert KLEWICKI Author-Workplace-Name: Institute of Chemical Technology of Food, Faculty of Biotechnology and Food Sciences, Technical University of Łódź, Łódź, Poland Title: In vitro fermentation of galactosyl derivatives of polyols by Lactobacillus strains Abstract: Probiotic lactic acid bacteria belonging to the species Lactobacillus casei, Lb. paracasei, and Lb. acidophilus were cultivated in the presence of galactosyl derivatives of erythritol, xylitol, and sorbitol, as well as the polyols themselves: erythritol, xylitol, sorbitol, lactitol, and glucose as a reference. After 48-h incubation, the profile of the main metabolic products (lactic and acetic acids) and the amount of the studied bacteria biomass were determined. It was found that none of the bacteria studied metabolised erythritol or xylitol. In the presence of these compounds, no increase of metabolic activity of the lactic fermentation bacteria was observed. On the other hand, the Lactobacillus sp. bacteria effectively utilised galactosyl derivatives of polyols. The bacteria growth in the presence of gal-polyols was comparable to their growth on glucose, while the fermentation profile was determined by the carbon source used. Keywords: polyols, prebiotics, Lactobacillus, growth response Journal: Czech Journal of Food Sciences Pages: 65-70 Volume: 27 Issue: 1 Year: 2009 DOI: 10.17221/176/2008-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/176/2008-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200901-0008.txt Handle: RePEc:caa:jnlcjf:v:27:y:2009:i:1:id:176-2008-CJFS