Czech Journal of Food Sciences, 2018 (vol. 36), issue 5
Rapid detection of microbial contamination in UHT milk: practical application in dairy industryFood Analysis, Food Quality and Nutrition
Martina KRAČMAROVÁ, Hana STIBOROVÁ, Šárka HORÁČKOVÁ, Kateřina DEMNEROVÁ
Czech J. Food Sci., 2018, 36(5):357-364 | DOI: 10.17221/24/2018-CJFS 
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...
Effect of yeast harvest moment on a brewing process in beer produced on an industrial scaleFood Microbiology and Safety
Krzysztof KUCHARCZYK, Tadeusz TUSZYŃSKI, Krzysztof ŻYŁA
Czech J. Food Sci., 2018, 36(5):365-371 | DOI: 10.17221/157/2017-CJFS
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 (1
The measurement method of meat conductivityFood Analysis, Food Quality and Nutrition
Zdeněk BOHUSLÁVEK
Czech J. Food Sci., 2018, 36(5):372-377 | DOI: 10.17221/164/2018-CJFS
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...
Quality of beef diaphragm meat in naturally occurring Sarcocystic infection in cattleFood Analysis, Food Quality and Nutrition
Vytautas JANUSKEVICIUS, Grazina JANUSKEVICIENE, Gintare ZABORSKIENE
Czech J. Food Sci., 2018, 36(5):378-385 | DOI: 10.17221/89/2017-CJFS
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...
Effects of artificial sweeteners on Lemna minorFood Analysis, Food Quality and Nutrition
Klára KOBETIČOVÁ, Klára Anna MOCOVÁ, Lucie MRHÁLKOVÁ, Šárka PETROVÁ
Czech J. Food Sci., 2018, 36(5):386-391 | DOI: 10.17221/413/2016-CJFS
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...
Tocochromanol content in commercially prepared fried foodsFood Analysis, Food Quality and Nutrition
Monika SABOLOVÁ, Štěpán CZORNYJ, Jakub FIŠNAR, Marek DOLEŽAL, Dominika SOSNOVÁ, Kateřina MATĚJKOVÁ, Zuzana RÉBLOVÁ
Czech J. Food Sci., 2018, 36(5):392-402 | DOI: 10.17221/143/2018-CJFS
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....
Effect of glycerol on the physicochemical properties of cereal starch filmsFood Technology and Economy, Engineering and Physical Properties
Mona AGHAZADEH, Roselina KARIM, Russly ABDUL RAHMAN, Muhammad Tauseef SULTAN, Stuart Kenth JOHNSON, Maryam PAYKARY
Czech J. Food Sci., 2018, 36(5):403-409 | DOI: 10.17221/41/2017-CJFS
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...
Performance of a freeze concentration pilot plant during the start-up phaseFood Technology and Economy, Engineering and Physical Properties
Fulvia CHIAMPO
Czech J. Food Sci., 2018, 36(5):410-414 | DOI: 10.17221/313/2017-CJFS
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,...
Sensory quality of meat from crossbred boars in relation to their age and slaughter weightFood Technology and Economy, Engineering and Physical Properties
Lenka KOUŘIMSKÁ, Jaroslav ČÍTEK, Kateřina ZADINOVÁ, Monika OKROUHLÁ, Zdeňka PANOVSKÁ, Yunus KHATRI, Roman STUPKA
Czech J. Food Sci., 2018, 36(5):415-419 | DOI: 10.17221/151/2018-CJFS
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...
Rapid evaluation of fresh chicken meat quality by electronic noseFood Technology and Economy, Engineering and Physical Properties
Edita RAUDIENÉ, Darius GAILIUS, Rimanté VINAUSKIENÉ, Viktorija EISINAITÉ, Gintautas BALČINAS, Justina DOBILIENÉ, Laura TAMKUTÉ
Czech J. Food Sci., 2018, 36(5):420-426 | DOI: 10.17221/419/2017-CJFS
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)...