Template-Type: ReDIF-Article 1.0 Author-Name: Jan Velíšek Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology Prague, Prague, Czech Republic Author-Name: Karel Cejpek Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology Prague, Prague, Czech Republic Title: Biosynthesis of food constituents: Amino acids: 1. The glutamic acid and aspartic acid groups - a review Abstract: This review article gives a survey of principal pathways that lead to the biosynthesis of the proteinogenic amino acids of the glutamic acid group (glutamic acid, glutamine, proline, arginine) and aspartic acid group (aspartic acid, asparagine, threonine, methionine, lysine, isoleucine) starting with oxaloacetic acid from the citric acid cycle. There is an extensive use of reaction schemes, sequences, and mechanisms with the enzymes involved and detailed explanations using sound chemical principles and mechanisms. Keywords: biosynthesis, amino acids, glutamic acid, glutamine, proline, arginine, aspartic acid, asparagine, threonine, methionine, lysine, isoleucine Journal: Czech Journal of Food Sciences Pages: 1-10 Volume: 24 Issue: 1 Year: 2006 DOI: 10.17221/3287-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3287-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200601-0001.txt Handle: RePEc:caa:jnlcjf:v:24:y:2006:i:1:id:3287-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Ivan Bohačenko Author-Workplace-Name: Food Research Institute Prague, Prague, Czech Republic Author-Name: Josef Chmelík Author-Workplace-Name: Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic, Brno, Czech Republic Author-Name: Vratislav Psota Author-Workplace-Name: Research Institute of Brewing and Malting, Brno, Czech Republic Title: Determination of the contents of A- and B-starches in barley using Low Angle Laser Light Scattering Abstract: A method was proposed for the determination of the contents of A- and B-starches in barley and for the use in plant breeding stations and brewing/malting laboratories. A combination was used of classical methods (incl. crushing of barley kernels by a roll crusher, steeping in 0.02M HCl, repeated rubbing and filtering through the sieve of 0.08 mm), and novel pieces of know-how (treatment with β-glucanase and cellulase, alkalisation at pH = 10.0 and centrifugation of crude starch suspension through the layer of CsCl). In this way, barley starch of high purity was obtained at a very low loss, using Low Angle Laser Light Scattering for the determination of the size distribution of starch granules. The boundary of the particle size between the peaks of A-starch and B-starch (7 µm) was evaluated from the distribution curves, while the contents of A- and B-starches were calculated from the cumulative curves. As a whole, the method was internally validated and for its repeatability and uncertainty of measurement the stimates of standard deviation s = 1.56 and confidence interval L1,2 = x± 1.9% were established, respectively. Taking into account the generally well known difficulties associated with the extraction of substances from biological materials, in this case the separation of starch from barley kernels, we believe that the proposed method will bring satisfactory results in practice. Keywords: barley, A-starch, B-starch, starch granules, Low Angle Laser Light Scattering Journal: Czech Journal of Food Sciences Pages: 11-18 Volume: 24 Issue: 1 Year: 2006 DOI: 10.17221/3288-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3288-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200601-0002.txt Handle: RePEc:caa:jnlcjf:v:24:y:2006:i:1:id:3288-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Lucie Mandelová Author-Workplace-Name: Institute of Preventive Medicine, Faculty of Medicine, Masaryk University in Brno, Brno, Czech Republic Author-Name: Jiří Totušek Author-Workplace-Name: Institute of Preventive Medicine, Faculty of Medicine, Masaryk University in Brno, Brno, Czech Republic Title: Chemoprotective Effects of Broccoli Juice Treated with High Pressure Abstract: We investigated chemoprotective effects of broccoli juice, treated with high pressure method, using 500 MPa for a period of 10 minutes. By the use of this method, the conservation of nutritionally important substances occurs (for example vitamins, polyphenolic compounds, glucosinolates and other constituent substances). We followed the inhibition of mutagenicity of the model mutagen, N-nitroso-N-methylurea (MNU), by means of in vivo micronucleus test. After fourteen-day application of broccoli juice (0.2 ml/10 g of body weight of mouse) and after a single administration of MNU mutagen (50 mg/kg), a statistically significant decrease (p < 0.01) occurred of the number of micronuclei induced by the application of MNU. Broccoli juice treated with high pressure therefore seems to have a preventive potential against MNU-induced micronuclei formation in BALB/C mouse bone marrow cells. Keywords: micronucleus test, broccoli, antimutagenicity, MNU Journal: Czech Journal of Food Sciences Pages: 19-25 Volume: 24 Issue: 1 Year: 2006 DOI: 10.17221/3289-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3289-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200601-0003.txt Handle: RePEc:caa:jnlcjf:v:24:y:2006:i:1:id:3289-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Lütfiye Yilmaz Author-Workplace-Name: Department of Food Engineering, Faculty of Agriculture, Uludag University, Görükle, Bursa, Turkey Author-Name: Tülay Özcan Yilsay Author-Workplace-Name: Department of Food Engineering, Faculty of Agriculture, Uludag University, Görükle, Bursa, Turkey Author-Name: Arzu Akpinar Bayizit Author-Workplace-Name: Department of Food Engineering, Faculty of Agriculture, Uludag University, Görükle, Bursa, Turkey Title: The sensory characteristics of berry-flavoured kefir Abstract: Certain physicochemical and sensory characteristics of the flavoured kefir drink were studied during refrigerated storage. Kefir drink batches were prepared using 2% addition of kefir grains, incubation for 18 h and subsequent filtration. The batches were then flavoured with blackberry, raspberry and strawberry aromas in the concentrations of 0.05, 0.10 and 0.15%, respectively. The samples were taken for analysis on 1st, 4th, 7th, and 10th days of storage at 4 ± 1°C. The sensory analysis of the flavoured kefir samples revealed the best acceptability level on the 4th day of storage. Nevertheless, the samples were acceptable all throughout the storage. The percentage of the aroma addition significantly influenced the odour, flavour, texture, and mouth-feel, and the overall acceptability ratings. The higher percentage of the added aroma the more sensed, however, the lowest aroma addition was preferable. The pHs of the flavoured kefir drinks decreased throughout the storage time whereas, the titratable acidity, alcohol content and CO2 values increased. Keywords: kefir, physicochemical parameters, sensory characteristics Journal: Czech Journal of Food Sciences Pages: 26-32 Volume: 24 Issue: 1 Year: 2006 DOI: 10.17221/3290-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3290-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200601-0004.txt Handle: RePEc:caa:jnlcjf:v:24:y:2006:i:1:id:3290-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Eva Čonková Author-Workplace-Name: Institute of Pharmacy and Pharmacology, University of Veterinary Medicine in Košice, Košice, Slovak Republic Author-Name: Anna Laciaková Author-Workplace-Name: Institute of Pharmacy and Pharmacology, University of Veterinary Medicine in Košice, Košice, Slovak Republic Author-Name: Igor Štyriak Author-Workplace-Name: Institute of Animal Physiology, Slovak Academy of Sciences, Košice, Slovak Republic Author-Name: Ludwik Czerwiecki Author-Workplace-Name: Institute of Agricultural and Food Biotechnology, Warsaw, Poland Author-Name: Grażyna Wilczyńska Author-Workplace-Name: Institute of Agricultural and Food Biotechnology, Warsaw, Poland Title: Fungal contamination and the levels of mycotoxins (Don and Ota) in cereal samples from poland and east slovakia Abstract: The cereal samples were taken immediately after harvest from the selected localities of Poland(45 samples) and East Slovakia(60 samples). Fungal contamination of these samples was investigated and subsequently the presence of two important mycotoxins, deoxynivalenol (DON) and ochratoxin A (OTA), was quantitatively examined. Concerning mould contamination, no difference was observed between the samples from Polandand East Slovakia. The highest incidence was observed of Fusarium, Aspergillus, and Penicillium genera. However, most of the investigated samples of wheat, rye, and barley contained less than 104 cfu/g. The limit 750 ppb for DON in cereals and their products, recommended by the European Mycotoxin Awareness Network (EMAN), was exceeded only by one wheat sample (4.5%) fromPoland, but by seven wheat samples (14.6%) fromSlovakia. None cereal sample investigated for OTA exceeded the allowed limit - 5 µg/kg. Keywords: wheat, rye, barley, microscopic fungi, ochratoxin A (OTA), deoxynivalenol (DON) Journal: Czech Journal of Food Sciences Pages: 33-40 Volume: 24 Issue: 1 Year: 2006 DOI: 10.17221/3291-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3291-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200601-0005.txt Handle: RePEc:caa:jnlcjf:v:24:y:2006:i:1:id:3291-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Agnieszka Kosińska Author-Workplace-Name: Department of Food Analysis, Division of Food Science, Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Olsztyn, Poland Author-Name: Uttam D. Chavan Author-Workplace-Name: Biotechnology Centre, Mahatma Phule Agricultural University, Rahuri, India Author-Name: Ryszard Amarowicz Author-Workplace-Name: Department of Food Analysis, Division of Food Science, Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Olsztyn, Poland Title: Separation of low molecular weight rapeseed proteins by RP-HPLC-DAD - a short report Abstract: Low molecular weight proteins were extracted and isolated from rapeseed and analysed using the HPLC-DAD method. The separation of proteins and phenolic compounds was done on the reversed phase C18 column with a gradient of acetonitrile in water. The chromatogram was characterised by two peaks of low molecular weight proteins with the retention times of 19.92 and 23.24 min. Additional three main peaks of phenolic constituents were recorded on the chromatogram. One of them with maximum of UV spectrum at 328 nm was identified as sinapic acid derivatives. Keywords: HPLC, rapeseed, low molecular weight proteins, phenolics, phenolic acids Journal: Czech Journal of Food Sciences Pages: 41-44 Volume: 24 Issue: 1 Year: 2006 DOI: 10.17221/3292-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3292-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200601-0006.txt Handle: RePEc:caa:jnlcjf:v:24:y:2006:i:1:id:3292-CJFS