Czech Journal of Food Sciences, 2019 (vol. 37), issue 4

Efficacy of chemical agents and power ultrasound on biofilms formed by Asaia spp. - spoilage bacteria in beverage industriesFood Microbiology and Safety

Iveta Šístková, Iveta Horsáková, Miroslav Čeřovský, Helena Čížková

Czech J. Food Sci., 2019, 37(4):221-225 | DOI: 10.17221/235/2018-CJFS  

Spoilage bacteria were isolated from spoiled fruit-flavoured bottled water with a visual defect in the form of floating flocks. The bacteria were identified as Asaia lannensis using the PCR technique. The efficacy of five chemical agents commonly used in the beverage industry and of power ultrasound (PUS) on Asaia biofilms was studied. A static cultivation procedure on stainless steel plates was used and the efficacy of the chemical agents was tested in two stages. First, only the chemical agents were used. Second, the effect of the application of PUS for 1 min prior to the application of the chemical agents was tested. The...

Effect of oil contents on gluten network during the extrusion processingFood Analysis, Food Quality and Nutrition

Feng Jia, Jinshui Wang, Yu Chen, Xia Zhang, Qi Wang, Di Chen, Changfu Zhang

Czech J. Food Sci., 2019, 37(4):226-231 | DOI: 10.17221/31/2018-CJFS  

To investigate a comparative evaluation of the gluten polymerization properties at different oil contents during the extrusion processing, the electrophoretic profiles of the gluten, free sulfhydryl (SH) compounds, the secondary structure of gluten, glutenin macropolymer contents and gluten network were measured. Five gluten samples were formulated by adding different oil contents. The low molecular weight contents of gluten decreased as well as the high molecular weight contents increased during the extrusion processing. The free SH of gluten at 8 or 10% oil content drops significantly to a minimum. The β-sheets contents of gluten have significantly...

The influence of geographical origin on honey composition studied by Polish and Slovak honeysFood Analysis, Food Quality and Nutrition

Monika Tomczyk, Maria Tarapatskyy, Małgorzata Dżugan

Czech J. Food Sci., 2019, 37(4):232-238 | DOI: 10.17221/40/2019-CJFS  

Honey composition is mainly affected by botanical origin, however geographical factors as well as beekeeping practice and storage conditions can also influence its quality. The aim of the study was to determine the impact of geographical origin on physicochemical quality and biological activity of honey. For this reason Polish and Slovak varietal honeys, including per each country: 10 multifloral, 5 tilia, 5 rape, 5 acacia and 5 forest were compared according to their physicochemical parameters (free acidity, pH, electrical conductivity, moisture content, and colour intensity), sugar profile, diastase activity, as well as antioxidant activity (DPPH...

Metabolomics-based authentication of wines according to grape varietyFood Analysis, Food Quality and Nutrition

Leos Uttl, Kamila Hurkova, Vladimir Kocourek, Jana Pulkrabova, Monika Tomaniova, Jana Hajslova

Czech J. Food Sci., 2019, 37(4):239-245 | DOI: 10.17221/82/2019-CJFS  

In 2008, the European Commission highlighted the risk of wine mislabelling regarding the geographical origin and varietal identification. While analytical methods for the identification of wine by geographical origin exist, a reliable strategy for authentication of wine variety is still missing. Here, we investigate the suitability of the metabolomic fingerprinting of ethyl acetate wine extracts, using ultra-high-performance liquid chromatography coupled to high-resolution tandem mass spectrometry. In total, 43 white wine samples (three varieties) were analysed within our study. The generated data were processed by principal component analysis and...

The effect of drying temperature on the properties of gelatin from carps (Cyprinus carpio) skinFood Analysis, Food Quality and Nutrition

Joanna Tkaczewska, Maciej Wielgosz, Piotr Kulawik, Marzena Zając

Czech J. Food Sci., 2019, 37(4):246-251 | DOI: 10.17221/128/2018-CJFS  

The influence of drying temperature on the characteristics and gel properties of gelatine from Cyprinus carpio L. skin was studied. Gelatine was extracted from the carp skin using NaOH and ethanol pre-treatment method, extracted in water in 45°C and then dried in 4 different temperatures: 50, 70, 80°C and freeze-dried. The electrophoresis and functional properties of gelatines were investigated. Freeze drying allowed to obtain a high gelling force, and all other methods did not give satisfactory results. The proteins in gelatines dried at higher temperatures separated by electrophoresis gave severely blurred bands. It may be explained by...

Antioxidant properties and resveratrol content of Polish Regent wines from Podkarpacie regionFood Analysis, Food Quality and Nutrition

Sabina Bednarska, Aneta Dabrowa, Joanna Kisala, Idalia Kasprzyk

Czech J. Food Sci., 2019, 37(4):252-259 | DOI: 10.17221/222/2018-CJFS  

The antioxidant properties of cool-climate Regent wines from Podkarpacie region, Poland were investigated. Total polyphenols, total flavonoids, total monomeric anthocyanins, trans-resveratrol concentration, radical scavenging ability using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and total antioxidant capacity with TEAC and FRAP methods were measured. The average contents of the compounds determined for Regent wines were comparable to the respective data available in literature found for warm-climate wines. Correspondence Analysis of the data revealed the relation of total polyphenols content and antioxidant capacity and radical scavenging ability...

Estimation of the antioxidant properties of milk protein preparations hydrolyzed by Lactobacillus helveticus T80, T105 and B734Food Analysis, Food Quality and Nutrition

Katarzyna Skrzypczak, Waldemar Gustaw, Anna Kononiuk, Bartosz Sołowiej, Adam Waśko

Czech J. Food Sci., 2019, 37(4):260-267 | DOI: 10.17221/477/2017-CJFS  

The investigation determined the influence of Lactobacillus helveticus strains (T80, T105, B734 and DSMZ 20075) and Lactobacillus acidophilus La-05 (probiotic strain) on the antioxidant activity of whey and milk protein preparations. In order to indicate possible mechanism of antioxidant activity of the obtained hydrolysates, the reducing power (RP) assay, ability to neutralize free radicals and Fe2+ chelating activity analysis were employed. The results suggest that antioxidant activity of tested hydrolysates depends on the type of protein preparation (substrate) and the applied bacterial strain. The strongest antioxidant activity was exhibited by...

Onion waste as a rich source of antioxidants for meat productsFood Technology and Economy, Engineering and Physical Properties

Jan Bedrníček, Ivana Laknerová, Zuzana Linhartová, Jaromír Kadlec, Eva Samková, Jan Bárta, Veronika Bártová, Jan Mráz, Milan Pešek, Renata Winterová, Naděžda Vrchotová, Jan Tříska, Pavel Smetana

Czech J. Food Sci., 2019, 37(4):268-275 | DOI: 10.17221/68/2018-CJFS  

Onion skin is a waste produced in thousands of tons annually in the European Union. It is a rich natural source of flavonoids and its water extracts (as an environmentally friendly solvent) could be used as an antioxidant material for meat products. Therefore, antioxidant properties of onion skin water extracts (OSWEs) were tested on cooked pork patties. Pork patties were divided into five treatments: control (no antioxidant), 10 and 20% (w/w) of yellow OSWE, and 10 and 20% (w/w) of red OSWE. Antioxidant activity, total polyphenols, thiobarbituric acid reactive substances (TBARS), and sensory analysis were assessed. Patties with added antioxidants...

Influence of milling whole wheat grains and particle size on thermo-mechanical properties of flour using MixolabFood Technology and Economy, Engineering and Physical Properties

Joseane Bressiani, Tatiana Oro, Paola Maria Lopes Da Silva, Flávio Martins Montenegro, Telma Elita Bertolin, Luiz Carlos Gutkoski, Marcia Arocha Gularte

Czech J. Food Sci., 2019, 37(4):276-284 | DOI: 10.17221/239/2018-CJFS  

Whole grain wheat flour (WG) of three different particles sizes (194.9, 609.4, and 830.0 µm) was prepared by milling whole grain. The effect of particle size on the thermo-mechanical properties of flour was investigated using Mixolab equipment and solvent retention capacity (SRC). The results showed that particle size influences the functionality of the gluten network. The SRC test revealed that the water absorption increased from 77.43% to 85.76%, with decrease in particle size. The C2 (protein weakening) values were correlated with the values for water absorption in the SRC and wet gluten test, respectively. The degree of gelatinization of starch...

Hydroxymethylfurfural content and colour parameters of cookies with defatted wheat germFood Technology and Economy, Engineering and Physical Properties

Marijana Sakač, Pavle Jovanov, Jovana Petrović, Lato Pezo, Aleksandar Fišteš, Ivana Lončarević, Biljana Pajin

Czech J. Food Sci., 2019, 37(4):285-291 | DOI: 10.17221/324/2017-CJFS  

Defatted wheat germ was used to substitute wheat flour by 5-15% to produce cookies enriched with protein, fat, sugar and minerals. The effects of different level of substitution of wheat flour by defatted wheat germ and dough moisture content (20-24%) on hydroxymethylfurfural (HMF) formation in cookies were investigated. Colour parameters (L*, a*, and b*) were also measured, total colour difference (ΔE) and browning index (BI) were calculated and their correlations with HMF content were studied. The substitution of wheat flour by defatted wheat germ led to a higher HMF content compared to control cookies (P < 0.05). However, its formation...

Effect of components in homogeneous extraction suspensions of pea and sweet buckwheat on γ-aminobutyric acid synthesisFood Technology and Economy, Engineering and Physical Properties

Yulong Huang, Na Chen, Fengxia Wang, Shen Song, Jie Guo, Zhongcun Pang, Ji Zhang

Czech J. Food Sci., 2019, 37(4):292-300 | DOI: 10.17221/480/2017-CJFS  

The effects of calcium chloride (CaCl2), vitamin B6 (VB6), and monosodium glutamate (MSG) on the synthesis of γ-aminobutyric acid (GABA) in the mixed homogeneous suspension of pea and sweet buckwheat (1:1 w/w) were investigated. The composition formula of raw materials in the homogeneous fluid for GABA synthesis was optimized via response surface methodology (RSM). The result showed that the increased content of GABA was dependent on the addition of CaCl2, VB6, and MSG to the mixed suspension. Box-Behnken design indicated that the optimal added components for GABA synthesis were: CaCl2 at a concentration of 0.85 mmol/l, VB6 at a concentration...