Template-Type: ReDIF-Article 1.0 Author-Name: Karolina CHRISTA Author-Workplace-Name: Department of Functional Properties of Food, Division of Food Science, Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Olsztyn, Poland Author-Name: Maria SORAL-ŚMIETANA Author-Workplace-Name: Department of Functional Properties of Food, Division of Food Science, Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Olsztyn, Poland Title: Buckwheat grains and buckwheat products - nutritional and prophylactic value of their components - a review Abstract: Buckwheat is introduced into the diet as an alternative crop of renewed interest due to its nutritive and health-promoting value. Experiments with animal models have demonstrated that buckwheat flour may alleviate diabetes, obesity, hypertension, and hypercholesterolemia. A number of nutraceutical compounds exist in buckwheat grains and other tissues. These are a rich source of starch, proteins, antioxidants, and dietary fibre as well as trace elements. The biological value (BV) of buckwheat proteins is comparable to BV of other protein sources. Besides high-quality proteins, buckwheat grains contain some components with prophylactic value: flavonoids, fagopyrins, or thiamin-binding proteins. For the food industry, buckwheat grains are a valuable raw material to be used for the production of functional foods. Buckwheat flour may be a valuable and important ingredient in diets or food products, taking into consideration its nutritive value and potential promotion of human health.Keywords: Keywords: buckwheat grains, nutritional components, resistant starch and dietary fibre, healing effect of components, dietary and prophylactic value, allergic reaction of buckwheat proteins Journal: Czech Journal of Food Sciences Pages: 153-162 Volume: 26 Issue: 3 Year: 2008 DOI: 10.17221/1602-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/1602-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200803-0001.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:3:id:1602-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Lucia Brindzová Author-Workplace-Name: Institute of Biochemistry, Nutrition and Health Protection, Department of Nutrition and Food Evaluation, Author-Name: Milan Čertík Author-Workplace-Name: Institute of Biotechnology and Food Science, Department of Biochemical Technology and Author-Name: Peter RAPTA Author-Name: Michal Zalibera Author-Name: Anna Mikulajová Author-Workplace-Name: Institute of Biochemistry, Nutrition and Health Protection, Department of Nutrition and Food Evaluation, Author-Name: Mária Takácsová Author-Workplace-Name: Institute of Biochemistry, Nutrition and Health Protection, Department of Nutrition and Food Evaluation, Title: Antioxidant activity, β-glucan and lipid contents of oat varieties Abstract: The antioxidant activity, total phenolic and β-glucans contents, and the fatty acid profile of total lipids in covered (black and yellow) and naked oats were studied. Oats with black hulls showed a significantly higher antioxidant activity in 2,2'-azino-di-[3-ethylbenzthiazoline sulphonate] (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) based tests in comparison to the grains with yellow hulls and those of the naked varieties. Radical scavenging activity of oats determined by electron paramagnetic resonance (EPR)/spin-trapping test did not depend on the colour of the grain hulls, but the naked grains showed a lower ability in scavenging reactive radicals. A positive correlation between the content of β-glucans in covered oat grains and the amount of reactive radicals scavenged was observed. Total phenolic content in the black oats was significantly higher than in the yellow and naked oat varieties. However, no significant differences in the fatty acid profile between the naked and covered oats were found, and the common fatty acids being linoleic, oleic, and palmitic acids. Keywords: oat, antioxidants, phenolic compounds, β -glucans, fatty acids, EPR Journal: Czech Journal of Food Sciences Pages: 163-173 Volume: 26 Issue: 3 Year: 2008 DOI: 10.17221/2564-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/2564-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200803-0002.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:3:id:2564-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Nazan Celikel Author-Workplace-Name: Department of Dairy Technology, Faculty of Agriculture, Ege University, Izmir, Turkey Author-Name: Gökhan Kavas Author-Workplace-Name: Department of Dairy Technology, Faculty of Agriculture, Ege University, Izmir, Turkey Title: Antimicrobial properties of some essential oils against some pathogenic microorganisms Abstract: Investigations were carried out to assess the efficiency of five plant essential oils: thyme, myrtle, laurel, sage, and orange oils as natural food preservatives. The effect of the plant essential oils against Escherichia coli, Listeria monocytogenes, Staphylococcus aureus and Candida albicans at concentrations of 5-20 µl/disk (diameter 6 mm) and 0.5-3% (v/v) was studied in agar diffusion test medium and milk medium. The essential oils of these extracts exhibited markedly antibacterial and bacteriostatic activity, with thyme showing the highest inhibition and orange the lowest. However, with thyme extract, high inhibitory activity was observed for all tested concentrations, L. monocytogenes showed less sensitivity towards essential oil extracts. Keywords: essential oils, antimicrobial activity, pathogens, milk Journal: Czech Journal of Food Sciences Pages: 174-181 Volume: 26 Issue: 3 Year: 2008 DOI: 10.17221/1603-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/1603-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200803-0003.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:3:id:1603-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Ondřej Mikeš Author-Workplace-Name: Department of Viticulture and Enology, Faculty of Horticulture, Mendel University of Agriculture and Forestry in Brno, Lednice, Czech Republic Author-Name: Naděžda Vrchotová Author-Workplace-Name: Institute of Systems Biology and Ecology, Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic Author-Name: Jan Tříska Author-Workplace-Name: Institute of Systems Biology and Ecology, Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic Author-Name: Marie Kyseláková Author-Workplace-Name: Department of Viticulture and Enology, Faculty of Horticulture, Mendel University of Agriculture and Forestry in Brno, Lednice, Czech Republic Author-Name: Jan Šmidrkal Author-Workplace-Name: Department of Dairy and Fat Technology, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Title: Distribution of major polyphenolic compounds in vine grapes of different cultivars growing in South Moravian vineyards Abstract: The main chemoprotective polyphenolic compounds in the Vitis vinifera berries, rachis, and pedicels of 10 cultivars classified for the production of wine and growing in Southern Moravian vineyards, the Czech Republic, were studied. The following compounds were determined in the frozen fresh berries: gallic acid (1.8-13.3 mg/kg), catechin (70.3-659.1 mg/kg), epicatechin (67.1-237.2 mg/kg), trans-resveratrol (0.1-1.5 mg/kg), and pterostilbene (in traces); in the freeze-dried rachis and pedicels: rutin (10.5-68.6 mg/kg), isoquercitrine (29.8-218.3 mg/kg), catechin (283.7-2227 mg/kg), epicatechin (47.2-215.2 mg/kg), trans-resveratrol (2.6-37.1 mg/kg), and pterostilbene (0.01-0.13 mg/kg), respectively. The contents of polyphenolic compounds were different in various cultivars. The highest levels of catechin and epicatechin were found in the grapes of cv. Blauer Burgunder (3195 mg/kg), in which the second highest content of trans-resveratrol (33.2 mg/kg) was also found. The content of pterostilbene in the whole berries or stems was estimated for the first time. The rachis and pedicels could serve as a prospective source of polyphenolic compounds. Keywords: Vitis vinifera L., cultivars, polyphenolic compounds, berries, stems, HPLC Journal: Czech Journal of Food Sciences Pages: 182-189 Volume: 26 Issue: 3 Year: 2008 DOI: 10.17221/1591-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/1591-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200803-0004.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:3:id:1591-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Petr ŠTERN Author-Workplace-Name: Institute of Hydrodynamics, Academy of Sciences of the Czech Republic, Prague, Czech Republic Author-Name: Jan POKORNÝ Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: Alena ŠEDIVÁ Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: Zdeňka PANOVSKÁ Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Title: Rheological and sensory characteristics of yoghurt-modified mayonnaise Abstract: Rheological and textural characteristics were studied in a set of 11 samples of yoghurt-modified mayonnaise at 15, 20, and 25°C. The rheometer Rheostress 300 was used to determine the static yield value, apparent viscosity, thixotropy, and elasticity. The sensory texture and flavour profiles were developed and determined in agreement with the respective international standards, using a group of selected and trained assessors. The yield value and apparent viscosity substantially decreased with increasing temperature, but thixotropy and sensory characteristics were not significantly affected by temperature. Linear and semilogarithmic relations were observed between the analytical parameters, but more complex relations, showing a maximum or a minimum, were found in some cases. Thixotropy was related to most of the sensory parameters, viscosity was related to spreadability, and significant relationships existed between the texture acceptability and the flavour acceptability. Rheological measurements were thus useful for a rapid prediction of the sensory properties of yoghurt-modified mayonnaises, but could not be used to replace any textural analysis. Keywords: mayonnaise, rheology, sensory analysis, texture, yoghurt Journal: Czech Journal of Food Sciences Pages: 190-198 Volume: 26 Issue: 3 Year: 2008 DOI: 10.17221/2566-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/2566-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200803-0005.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:3:id:2566-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Karel Hoke Author-Workplace-Name: Food Research Institute Prague, Prague, Czech Republic Author-Name: Aleš Landfeld Author-Workplace-Name: Food Research Institute Prague, Prague, Czech Republic Author-Name: Jiří Severa Author-Workplace-Name: Faculty of Mechanical Engineering, Czech Technical University Prague, Prague, Czech Republic Author-Name: Karel Kýhos Author-Workplace-Name: Food Research Institute Prague, Prague, Czech Republic Author-Name: Rudolf Žitný Author-Workplace-Name: Faculty of Mechanical Engineering, Czech Technical University Prague, Prague, Czech Republic Author-Name: Milan Houška Author-Workplace-Name: Food Research Institute Prague, Prague, Czech Republic Title: Prediction of the average surface heat transfer coefficient for model foodstuffs in a vertical display cabinet Abstract: Calculations of transient temperatures of food products after they are transferred from a warm environment into a display cabinet, require data on the surface heat transfer coefficient (SHTC). There is no forced air flow in an ordinary display cabinet, so the energy transfer is achieved mainly by free convection, conduction to a supporting plate, and radiation. Theoretical analysis of the heat transfer to a cylindrical sample demonstrates the relative influences of these mechanisms. This work investigates the apparent surface transfer coefficients with metal models. Heated models were placed individually (bare) in containers with and without lids. Each model was surrounded by identical containers filled with water. These were initially at the same temperature as the model or at the mean cabinet temperature. There were one, two, or three layers of these water containers. From the measured time-temperature histories of the model and the air surrounding the model, the SHTCs were calculated as functions of time and transformed into the dependencies between SHTC and temperature difference. The highest SHTCs were observed when the model was placed directly on the metal shelf of the display cabinet. The models surrounded by cool water containers showed lower SHTC values. The lowest SHTC values were found with the models placed in the middle of three layers of warm water containers. Placing the model on an insulating base leads to a lower SHTC. This effect confirms that the heat conduction through the substrate increases the heat transfer from the model and thus increases the average value of the apparent SHTC. Keywords: SHTC, vertical display cabinet, correlations, food safety Journal: Czech Journal of Food Sciences Pages: 199-210 Volume: 26 Issue: 3 Year: 2008 DOI: 10.17221/1590-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/1590-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200803-0006.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:3:id:1590-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Mohamed Fawzy Ramadan Author-Workplace-Name: Biochemistry Department, Faculty of Agriculture, Zagazig University, Zagazig, Egypt Author-Name: Mohsen Mohamed Selim Asker Author-Workplace-Name: Microbial Biotechnology Department, National Research Center, Dokki, Cairo, Egypt Author-Name: Zeinab K. Ibrahim Author-Workplace-Name: Botany Department, Faculty of Science, Cairo University, Cairo, Egypt Title: Functional bioactive compounds and biological activities of Spirulina platensis lipids Abstract: The compositions and concentrations of lipid classes, fatty acids, tocopherols were determined in the lipids from blue-green microalga Spirulina platensis. Total lipids (TL) recovered using chloroform: methanol (2:1, v/v) were found to be 163.5 g/kg (on dry weight basis). The level of neutral lipids was the highest, followed by glycolipids and phospholipids, respectively. Among TL and lipid classes, palmitic, γ-linolenic and linoleic acids were the dominating fatty acids. Compared to the neutral lipids, the polar fractions were generally characterised by higher percentages of saturated fatty acids. The recovered lipids were characterised by high percentage of tocopherols, wherein γ-tocopherol constitutes about 73% of total tocopherols present, the rest being γ-tocopherol. Spirulina platensis lipids exhibited a strong radical scavenging activity towards stable DPPH free radicals, whereas 27% of DPPH radicals were quenched after 2 h incubation. TL and lipid classes inhibited the growth of different microorganisms except gram-negative bacteria. At high concentrations, the tested lipids appeared more effective against A. niger (28.3 ± 1.53 mm). The information obtained in the present investigation is useful for lipid characterisation and further chemical and nutritional investigations of Spirulina platensis. Keywords: Spirulina platensis, blue-green microalga, lipids, fatty acids, tocopherols, antiradical action, antimicrobial activity Journal: Czech Journal of Food Sciences Pages: 211-222 Volume: 26 Issue: 3 Year: 2008 DOI: 10.17221/2567-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/2567-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200803-0007.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:3:id:2567-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Eleni SINDOU Author-Workplace-Name: Winery Zitsa, Union of Agricultural Cooperatives of Ioannina, Ioannina, Greece Author-Name: Vasilios VAIMAKIS Author-Workplace-Name: Winery Zitsa, Union of Agricultural Cooperatives of Ioannina, Ioannina, Greece Author-Name: Tiverios VAIMAKIS Author-Workplace-Name: Laboratory of Industrial Chemistry and Author-Name: Ioannis G. ROUSSIS Author-Workplace-Name: Laboratory of Food Chemistry, Department of Chemistry, University of Ioannina, Ioannina, Greece Title: Effect of juice clarification by flotation on the quality of white wine and orange juice and drink - Short Communication Abstract: White wines of Debina cultivar were made from musts clarified by flotation using nitrogen as foaming agent. Flotation using air as the foaming agent (must hyperoxidation), without SO2 addition, was also applied. Turbidity and suspended solids were lower in must clarified by flotation using nitrogen than in that clarified by sedimentation (control). Flotation with hyperoxidation led to a reduction of must phenolics. All experimental wines exhibited similar gross compositions (alcohol, reducing sugars, total acidity, and volatile acidity). Wines made from musts clarified by flotation using nitrogen had similar total phenolic content, browning capacity, and organoleptic quality as the control wines. Wines made from musts clarified by flotation using air had lower total phenolic contents and browning capacity than were those in control wines. These wines were of well acceptable quality but exhibited a slightly oxidised aftertaste. The results indicate that flotation using nitrogen can be effective in the production of typical Debina wine, while flotation using air may be useful in that of table wine without SO2 addition. Orange juice was clarified by flotation using nitrogen or air as the foaming agent. Orange juice clarified by flotation using nitrogen as the foaming agent exhibited lower turbidity and a similar pulp content to that clarified by centrifugal separator (control). It had an acceptable taste and aroma. Juice clarified by flotation using air as the foaming agent, along with pectolytic enzyme treatment, exhibited much lower turbidity and pulp content compared to control. The clear juice had an acceptable taste but no aroma. The fermented clear juice was averagely rated, exhibiting a pleasant aroma and only a slightly bitter taste. The results indicate that flotation using nitrogen can be effective in the production of natural orange juice, while flotation using air may be useful in the production of orange drink. Keywords: must, wine, orange juice, orange drink, flotation, hyperoxidation, pectolytic enzyme Journal: Czech Journal of Food Sciences Pages: 223-228 Volume: 26 Issue: 3 Year: 2008 DOI: 10.17221/2565-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/2565-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200803-0008.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:3:id:2565-CJFS