Template-Type: ReDIF-Article 1.0 Author-Name: Martina KRAČMAROVÁ Author-Workplace-Name: Department of Biochemistry and Microbiology and Author-Name: Hana STIBOROVÁ Author-Workplace-Name: Department of Biochemistry and Microbiology and Author-Name: Šárka HORÁČKOVÁ Author-Workplace-Name: Department of Dairy, Fat and Cosmetics; Faculty of Food and Biochemical Technology, University of Chemistry and Technology Prague, Prague, Czech Republic Author-Name: Kateřina DEMNEROVÁ Author-Workplace-Name: Department of Biochemistry and Microbiology and Title: Rapid detection of microbial contamination in UHT milk: practical application in dairy industry Abstract: Microbial quality of ultra-high temperature (UHT) milk is usually ascertained by a total bacterial count (TBC) cultivation. But this is time consuming, so there is a tendency to search for faster and simpler methods. We compared three instruments, focusing on shortening the detection time and their suitability for practical use in dairy plants. Two of them, RapiScreen Dairy 1000 and Promilite III, detect microbial contamination by measuring adenosine triphosphate bioluminescence; the third, GreenLight, is based on oxygen consumption analysis. In the laboratory experiments, samples of UHT milk, were spiked with low concentration of microorganisms and then the level of microbial contamination was evaluated using the above-mentioned instruments together with cultivation method as a control. The instruments were also applied in a dairy plant to test 182 real samples. All investigated methods determined microbial quality faster than the TBC, but in some cases false positive and false negative results were obtained. Therefore, precise testing including optimizing pre-incubation time for bacteria enrichment is needed prior to industrial use. Keywords: ATP bioluminescence, oxygen-consumption analysis, total bacterial count, milk contamination Journal: Czech Journal of Food Sciences Pages: 357-364 Volume: 36 Issue: 5 Year: 2018 DOI: 10.17221/24/2018-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/24/2018-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-201805-0001.txt Handle: RePEc:caa:jnlcjf:v:36:y:2018:i:5:id:24-2018-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Krzysztof KUCHARCZYK Author-Name: Tadeusz TUSZYŃSKI Author-Workplace-Name: Cracow School of Health Promotion, Cracow, Poland Author-Name: Krzysztof ŻYŁA Author-Workplace-Name: Departament of Food Biotechnology, Food Technology, University of Agricultural in Cracow, Cracow, Poland Title: Effect of yeast harvest moment on a brewing process in beer produced on an industrial scale Abstract: The aim of this study was to determine the effect of yeast harvest timing on the process performance, total yeast count and the content of volatile components in beer. The experiments were performed on an industrial scale with fermentation and maturation conducted in three fermentation tanks with a capacity of 3800 hl (cylindro-conical tanks - CCT). All processes were carried out using the same technological conditions. The worts were aerated with sterile air and yeast after the second fermentation (third generation) was added. The duration of the maturation phase and the processes of the yeast harvest were conducted at different times (1st, 4th and 6th day) after finishing the primary fermentation process. During fermentation and maturation, changes in the contents of the extract, yeast, and volatile components were investigated. These experiments showed that the use of different times during yeast harvest had a significant impact on the course of fermentation and maturation and impact on the total yeast count during the maturation process and on the amount of volatile components in beer. With a delay in the start of yeast cropping, the content of acetaldehyde and vicinal diketones decreased and the content of esters increased. The timing of the yeast crop significantly influenced the final beer quality. Keywords: beer, cylindro-conical tank, volatile components, yeast harvest, wort Journal: Czech Journal of Food Sciences Pages: 365-371 Volume: 36 Issue: 5 Year: 2018 DOI: 10.17221/157/2017-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/157/2017-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-201805-0002.txt Handle: RePEc:caa:jnlcjf:v:36:y:2018:i:5:id:157-2017-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Zdeněk BOHUSLÁVEK Title: The measurement method of meat conductivity Abstract: This paper analyses the properties of electrode methods and contactless inductive methods of the conductivity measurement of biological tissue, which are one of the few which are able to measure the potentials of corresponding components of complex conductivity, i.e. the real reactive conductivity of a resistive and an imaginary component. The analysis was performed by computer modelling and experimental measurements. The publication describes the modelling of currents and of the potential by electrode and methods on tissue phantoms using the finite element method. The Comsol Multiphysics v3.4 program was used for the calculations. The results are presented in 2D and 3D diagrams. Experimental measurements with electrodes in phantom tissues with different conductivity were also conducted and the components of the complex conductivity were evaluated with an RLC Bridge and most accurately by using a lock-in amplifier. Results and experience from the experiments will make it possible to proceed with the next phase of research focused on measuring conductivity and dielectric properties in different types of meat. Keywords: biological tissue, conductivity, contactless inductive methods, electrode method, meat, 2D and 3D diagrams Journal: Czech Journal of Food Sciences Pages: 372-377 Volume: 36 Issue: 5 Year: 2018 DOI: 10.17221/164/2018-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/164/2018-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-201805-0003.txt Handle: RePEc:caa:jnlcjf:v:36:y:2018:i:5:id:164-2018-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Vytautas JANUSKEVICIUS Author-Workplace-Name: Department of Veterinary Pathobiology, Lithuanian University of Health Sciences, Veterinary Academy, Kaunas, Lithuania Author-Name: Grazina JANUSKEVICIENE Author-Workplace-Name: Department of Food Safety and Quality Author-Name: Gintare ZABORSKIENE Author-Workplace-Name: Department of Food Safety and Quality Author-Workplace-Name: Food Institute, Kaunas University of Technology, Kaunas, Lithuania Title: Quality of beef diaphragm meat in naturally occurring Sarcocystic infection in cattle Abstract: The aim of this study was to investigate the possible harmful effect of Sarcocystis parasites on bovine diaphragm meat quality. Meat samples were collected from 120 bulls aged 20-24 months. Meat quality was investigated using microbiological and physico-chemical (RP-HPLC, GC) methods 48 hours after slaughter. Sarcocystis infection was associated with increased fat content, lightness L* and drip loss, and decreased ash and protein percentages. Infection also had a significant effect on the amount of amino acids (AAs), which slowly decreased as the number of sarcocysts increased. The total amount of AAs correlated with glutamic acid content (R = 0.966, P < 0.05). Heavily infected samples contained significantly lower amounts of putrescine, histamine, spermine and spermidine (P < 0.05) and a noticeable increase in the total count of aerobic microorganisms, but no change in the numbers of E. coli and coliform bacteria in comparison with no infected samples. Sarcocysts in beef diaphragms did not cause serious changes in the technological quality of the meat, but the biological quality of infected meat was reduced. Keywords: amino acids, bacterial count, beef, Sarcocysts Journal: Czech Journal of Food Sciences Pages: 378-385 Volume: 36 Issue: 5 Year: 2018 DOI: 10.17221/89/2017-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/89/2017-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-201805-0004.txt Handle: RePEc:caa:jnlcjf:v:36:y:2018:i:5:id:89-2017-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Klára KOBETIČOVÁ Author-Name: Klára Anna MOCOVÁ Author-Name: Lucie MRHÁLKOVÁ Author-Workplace-Name: Department of Environmental Chemistry, Faculty of Technology and Chemistry, University of Chemistry and Technology Prague Author-Name: Šárka PETROVÁ Author-Workplace-Name: Institute of Experimental Botany AS CR, Prague, Czech Republic Title: Effects of artificial sweeteners on Lemna minor Abstract: Artificial sweeteners are common micropollutants in the aquatic environment. They were detected both in surface waters and in groundwater. Human toxicity has also been studied quite intensively but their ecotoxicity has not been studied so far. To assess the impact of four artificial sweeteners (aspartame, sucralose, saccharine, and acesulfame K) and one natural sweetener (stevioside) on freshwater plants, a growth inhibition test was set up in the macrophyte duckweed (Lemna minor). Subsequently full dose-response curves were established by exposing L. minor plants to concentrations of each individual sweetener ranging from 6.25 mg/l up to 100 mg/l for 7 days. Three different endpoints were tested: frond number, frond area and total chlorophyll content. Tests were performed under sterile conditions. Sweeteners had various effects on Lemna plants. Saccharine, acesulfame K and stevioside did not cause any significant negative effects on any of the measured parameters. On the contrary, stevioside and saccharine caused slowly stimulative effects. Aspartame and sucralose inhibited growth parameters (frond number and frond area) but the chlorophyll content was not affected. Keywords: acesulfame K, aquatic environment, aspartame, duckweed, saccharine, stevioside, sucralose, toxicity Journal: Czech Journal of Food Sciences Pages: 386-391 Volume: 36 Issue: 5 Year: 2018 DOI: 10.17221/413/2016-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/413/2016-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-201805-0005.txt Handle: RePEc:caa:jnlcjf:v:36:y:2018:i:5:id:413-2016-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Monika SABOLOVÁ Author-Name: Štěpán CZORNYJ Author-Workplace-Name: Department of Food Analysis and Nutrition, Faculty of Food and Biochemical Technology, University of Chemistry and Technology Prague, Prague, Czech Republic Author-Name: Jakub FIŠNAR Author-Workplace-Name: Department of Food Analysis and Nutrition, Faculty of Food and Biochemical Technology, University of Chemistry and Technology Prague, Prague, Czech Republic Author-Name: Marek DOLEŽAL Author-Workplace-Name: Department of Food Analysis and Nutrition, Faculty of Food and Biochemical Technology, University of Chemistry and Technology Prague, Prague, Czech Republic Author-Name: Dominika SOSNOVÁ Author-Workplace-Name: Department of Food Analysis and Nutrition, Faculty of Food and Biochemical Technology, University of Chemistry and Technology Prague, Prague, Czech Republic Author-Name: Kateřina MATĚJKOVÁ Author-Workplace-Name: Department of Food Analysis and Nutrition, Faculty of Food and Biochemical Technology, University of Chemistry and Technology Prague, Prague, Czech Republic Author-Name: Zuzana RÉBLOVÁ Author-Workplace-Name: Department of Food Analysis and Nutrition, Faculty of Food and Biochemical Technology, University of Chemistry and Technology Prague, Prague, Czech Republic Title: Tocochromanol content in commercially prepared fried foods Abstract: In the scientific literature, there is not reliable information about the vitamin E content of commercially prepared fried foods. Therefore, tocochromanols were determined in 44 samples of french fries and 33 samples of potato chips and similar fried snacks. The total tocochromanol content of the french fries varied in the range of 1.7-96.9 mg/kg, α-tocopherol 0.3-76.1 mg/kg, and vitamin E (expressed in α-tocopherol equivalents) 0.6-76.4 mg/kg. The total content of tocochromanols in the fried snack products varied in the range of 39.9-204.6 mg/kg, α-tocopherol 20.4-133.7 mg kg, and vitamin E 29.8-134.6 mg α-tocopherol equivalent/kg. After a comparison of fat content, and taking into account the reference intake of fat and vitamin E, the french fries were generally a worse source of vitamin E than fat. The fried snack products were usually a better source of vitamin E than fat. In the both types of fried foods, the total content of tocochromanols was most influenced by the total content of fat. The content of α-tocopherol and the vitamin E content were mainly affected by the kind of fat (oil) used for frying. Keywords: fatty acids, french fries, polymerized triacylglycerols, potato chips, vitamin E Journal: Czech Journal of Food Sciences Pages: 392-402 Volume: 36 Issue: 5 Year: 2018 DOI: 10.17221/143/2018-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/143/2018-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-201805-0006.txt Handle: RePEc:caa:jnlcjf:v:36:y:2018:i:5:id:143-2018-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Mona AGHAZADEH Author-Workplace-Name: Department of Food Technology. Faculty of Food Science and Technology, University of Putra Malaysia (UPM), Serdang, Selangor, Malaysia. Author-Name: Roselina KARIM Author-Workplace-Name: Department of Food Technology. Faculty of Food Science and Technology, University of Putra Malaysia (UPM), Serdang, Selangor, Malaysia. Author-Name: Russly ABDUL RAHMAN Author-Workplace-Name: Department of Food Technology. Faculty of Food Science and Technology, University of Putra Malaysia (UPM), Serdang, Selangor, Malaysia. Author-Name: Muhammad Tauseef SULTAN Author-Workplace-Name: Department of Food Technology. Faculty of Food Science and Technology, University of Putra Malaysia (UPM), Serdang, Selangor, Malaysia. Author-Name: Stuart Kenth JOHNSON Author-Workplace-Name: School of Molecular and Life Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, Australia Author-Name: Maryam PAYKARY Author-Workplace-Name: Department of Food Technology. Faculty of Food Science and Technology, University of Putra Malaysia (UPM), Serdang, Selangor, Malaysia. Title: Effect of glycerol on the physicochemical properties of cereal starch films Abstract: The physical properties of corn, wheat and rice starch edible films with different level of glycerol were evaluated. Starch films exhibited an apparent endothermic peak in the range of 151-199°C with corn starch film with 1.6% glycerol having a relatively lower To and higher Tp. X-ray diffraction spectroscopy indicated that the corn, wheat, rice starch powders had ~ 39-49% crystallinity, whereas Fourier transform infrared spectra showed peaks associated with the tightly bound water present in the rice, corn, wheat starches. Overall, glycerol addition could enhance the water vapour pressure barrier properties of the films, but their tensile strength was reduced. Corn starch films were identified as the most suitable choice for edible packaging as its thermal characteristics indicated suggested a more acceptable sealability. Rice starch films is proposed as the better choice for coating as it showed better flexibility as indicted by lower tensile and higher elongation properties. Keywords: edible coting, edible film, plasticizers, DSC Journal: Czech Journal of Food Sciences Pages: 403-409 Volume: 36 Issue: 5 Year: 2018 DOI: 10.17221/41/2017-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/41/2017-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-201805-0007.txt Handle: RePEc:caa:jnlcjf:v:36:y:2018:i:5:id:41-2017-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Fulvia CHIAMPO Title: Performance of a freeze concentration pilot plant during the start-up phase Abstract: In this paper are presented the findings obtained during the start-up of a freeze concentration pilot plant, that operated with suspension crystallisation and with simulated fruit juices. Solutions with different initial concentrations were tested, with and without acidification, to simulate fruit characteristics and behaviour. The experimental runs demonstrated that solution acidity has negligible effects on the process performance, whereas the results showed that the initial solution concentration influences the start-up duration. During this time, the solution concentration grows by about 10 °Brix, and the maximum quantity of ice content inside the crystalliser is always lower than 40% by weight. These findings can help to predict the performance of a freeze concentration plant and may facilitate achieving target concentrations in a more efficient mode. Taken together, the data suggest that the initial concentration of the processed juice influences start-up duration and the achievable final concentration. Keywords: crystalliser performance, crystal growth, crystal separation, ice content, suspension crystallization Journal: Czech Journal of Food Sciences Pages: 410-414 Volume: 36 Issue: 5 Year: 2018 DOI: 10.17221/313/2017-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/313/2017-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-201805-0008.txt Handle: RePEc:caa:jnlcjf:v:36:y:2018:i:5:id:313-2017-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Lenka KOUŘIMSKÁ Author-Workplace-Name: Department of Microbiology, Nutrition and Dietetics, Czech University of Life Sciences Prague, Czech Republic Author-Name: Jaroslav ČÍTEK Author-Workplace-Name: Department of Animal Science, Czech University of Life Sciences Prague, Czech Republic Author-Name: Kateřina ZADINOVÁ Author-Workplace-Name: Department of Animal Science, Czech University of Life Sciences Prague, Czech Republic Author-Name: Monika OKROUHLÁ Author-Workplace-Name: Department of Animal Science, Czech University of Life Sciences Prague, Czech Republic Author-Name: Zdeňka PANOVSKÁ Author-Workplace-Name: Department of Food Analysis and Nutrition, University of Chemistry and Technology Prague, Prague, Czech Republic Author-Name: Yunus KHATRI Author-Workplace-Name: Department of Food Science and Agri-food Supply Chain Management, Harper Adams University, Newport, United Kingdom Author-Name: Roman STUPKA Author-Workplace-Name: Department of Animal Science, Czech University of Life Sciences Prague, Czech Republic Title: Sensory quality of meat from crossbred boars in relation to their age and slaughter weight Abstract: The aim of this study was to evaluate the effect of age of boars and their slaughter weights on the pleasantness and intensity of pork meat taste and odour. A total of 652 sensory evaluations of meat samples from sixteen crossbred entire male pigs aged 121 to 136 days with slaughter weight of 80-120 kg were performed by sensory profiling method. The age was a greater factor influencing the level of boar taint than the slaughter weight of animals. There were significant differences in the intensity of boar odour between categories of young animals (121 days) and old animals (135-136 days) (P = 0.0473) and between categories of adult animals (128 days) and old animals (P = 0.0194). Among the evaluated descriptors stronger correlations were calculated between olfactometric than between taste descriptors. Significant correlations were found between androstenone levels in subcutaneous fat and the results of sensory evaluation of muscle samples from the oldest animals aged 135-136 days. Keywords: boar age, boar taint, live weight, sensory analysis, sexual maturation Journal: Czech Journal of Food Sciences Pages: 415-419 Volume: 36 Issue: 5 Year: 2018 DOI: 10.17221/151/2018-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/151/2018-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-201805-0009.txt Handle: RePEc:caa:jnlcjf:v:36:y:2018:i:5:id:151-2018-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Edita RAUDIENÉ Author-Workplace-Name: Institute of Metrology and Author-Name: Darius GAILIUS Author-Workplace-Name: Institute of Metrology and Author-Name: Rimanté VINAUSKIENÉ Author-Workplace-Name: Department of Food Science and Technology; Kaunas University of Technology, Kaunas, Lithuania Author-Name: Viktorija EISINAITÉ Author-Workplace-Name: Department of Food Science and Technology; Kaunas University of Technology, Kaunas, Lithuania Author-Name: Gintautas BALČINAS Author-Workplace-Name: Institute of Metrology and Author-Name: Justina DOBILIENÉ Author-Workplace-Name: Institute of Metrology and Author-Name: Laura TAMKUTÉ Author-Workplace-Name: Department of Food Science and Technology; Kaunas University of Technology, Kaunas, Lithuania Title: Rapid evaluation of fresh chicken meat quality by electronic nose Abstract: A prototype of electronic nose (e-nose) with the gas sensor system for evaluation of fresh chicken meat freshness was developed. In this paper a rapid, simple and not expensive system for fresh chicken meat spoilage detection was investigated that provides objective and reliable results. Quality changes in fresh chicken meat during storage were monitored by the metal oxide sensor (MOS) system and compared with the results of traditional chemical measurements. Gas sensor selection was tested for evaluation of volatile fatty acids (VFA) mainly representing meat spoilage.The study demonstrated that a correlation coefficient (R2 = 0.89) between e-nose signals and traditional chemical method was high. These results prove that the developed e-nose prototype has a potential for assessing fresh chicken meat freshness and allows discriminating meat into fresh, unsafe and spoiled. Keywords: detection system, meat freshness, MOS sensors Journal: Czech Journal of Food Sciences Pages: 420-426 Volume: 36 Issue: 5 Year: 2018 DOI: 10.17221/419/2017-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/419/2017-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-201805-0010.txt Handle: RePEc:caa:jnlcjf:v:36:y:2018:i:5:id:419-2017-CJFS