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Biocontamination in the dairy industry: The effect of raw milk conditioning film on the adhesion of Escherichia coliOriginal Paper

Zakariyae El hafa, Ikhlas Hani Chennoufi, Hafida Zahir, Mostafa El louali, Hassan Latrache

Czech J. Food Sci., 2025, 43(2):112-117 | DOI: 10.17221/91/2024-CJFS

Conditioning films on surfaces employed in the dairy industry serve as the precursors to the formation of pathogenic biofilms that impact product quality and consumer safety. Conditioning films have been studied from several aspects. However, there has been no study that evaluated the effect of raw milk conditioning film on the adhesion of Escherichia coli. This study investigated the adhesion of E. coli on glass and stainless-steel surfaces conditioned with raw milk and explored the surface properties potentially influencing this adhesion using the contact angle method. The results showed that after treating surfaces with raw milk, the adhesion of the bacteria on stainless steel and glass was significantly altered. Adhesion increased significantly on stainless steel (from 0.55 log10 to 2.8 log10) but it decreased on glass (from 1.56 log10 to 0.8 log10). Significant alterations were observed in the physicochemical properties of the surfaces. Glass was initially relatively hydrophilic (46.33°), while stainless steel was relatively hydrophobic (82.5°). After treatment, the glass became relatively more hydrophobic (74.6°), and stainless steel became relatively more hydrophilic (69.4°). The electron donor/acceptor components of glass decreased after the treatment, while these components increased for stainless steel. The significant changes in adhesion were hypothesized to be due to the modification of surface properties by the raw milk.

Immobilised Aspergillus niger lipase synthesises sn-1,3-dioleoyl-2-palmitoylglycerolOriginal Paper

Shanhui Chen, Renbin Liu, Dong Wang, Shiyou Li, Zhirong Yang

Czech J. Food Sci., 2025, 43(4):291-299 | DOI: 10.17221/143/2024-CJFS

sn-1,3-Dioleoyl-2-palmitoylglycerol (OPO) is a structural triglyceride with a specific distribution of fatty acids, which is an important component of breast milk fat and which can better promote the absorption of minerals and energy in infants. In this study, a lab-made immobilised Aspergillus niger lipase (IM-ANL), which is more economical than a commercial lipase, was used for hydrolysis to produce free fatty acids (FFA) and acidolysis interesterification to produce OPO. The enzyme was used for multiple purposes, reducing the cost of enzymatic production. The optimum conditions for hydrolysis were determined by experiments: the amount of IM-ANL enzyme dosage was 3%, the reaction temperature was 45 °C, and the reaction time was 48 h. The optimum conditions for acidolysis interesterification were as follows: the amount of IM-ANL enzyme dosage was 4%, the molar ratio of tripalmitin to oleic acid was 1 : 8, the reaction temperature was 55 °C, and the reaction time was 3 h. In this study, economical palm stearin and high oleic acid sunflower seed oil were selected as reaction raw materials, and the reaction temperature was moderate, the safety risk was low, the energy consumption was reduced, the process was more economical, and the economic value of high oleic acid vegetable oil was improved, which was conducive to the further promotion of OPO production.

Ginger essential oil-infused pectin-alginate films for extending sliced bread shelf lifeOriginal Paper

Nguyen Hong Khoi Nguyen, Nam Quoc Tran, Thuan Huynh Dinh Nguyen, Quyen Phuong Huynh

Czech J. Food Sci., 2025, 43(6):438-449 | DOI: 10.17221/24/2025-CJFS

This study examines composite films made from pectin and alginate, enhanced with ginger essential oil (GEO) at 0, 0.5, 1, and 1.5% concentration. The films were analysed for their structure, physical properties, antioxidant and antibacterial activities, and effectiveness in preserving sliced bread over 0, 2, 4, 6, and 8 days. The outcomes presented that incorporating GEO upgraded pectin-alginate films' properties. SEM images revealed increased essential oil distribution on the film surface with higher GEO concentrations, indicating good compatibility. Higher GEO concentrations enhanced the films' abilities to scavenge free radicals DPPH, 2,2-diphenyl-1-picrylhydrazyl; and ABTS, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and inhibit bacteria (Listeria monocytogenes and Escherichia coli). Furthermore, increasing GEO concentrations in the films helped maintain key quality attributes of sliced bread, such as moisture content, water activity, microbial counts, and firmness. Films with 1.0 and 1.5% GEO concentrations were the most effective in preserving bread, potentially inhibiting mould formation and maintaining sensory properties over the 8-day storage period. This study demonstrates that pectin-alginate films supplemented with GEO at 1 and 1.5% concentration are suitable for storing sliced bread.

Formulation optimisation for pilot-scale honey powder production: A response surface methodology and central composite design approachOriginal Paper

Angelina Risky Maharani, Lilik Eka Radiati, Agus Susilo, Firman Jaya, Anang Lastriyanto, Dewi Masyithoh

Czech J. Food Sci., 2024, 42(1):45-54 | DOI: 10.17221/215/2023-CJFS


This research aimed to optimise a pilot-scale formulation for seamless scale-up, considering critical variables such as the honey-to-maltodextrin ratio, temperature, and drying time. Employing response surface methodology with a central composite design approach, the investigation systematically assessed the impact of four key factors within predetermined upper and lower limits: honey volume (90–900 g % dry basis), maltodextrin (60–600 g), drying temperature (60–70 °C), and drying time (180–300 min). Subsequently, these factors were randomised and optimised using the Design Expert software system. The analysis of variance revealed the significant impact of each drying factor, their interactions, and squared squares on the honey-to-maltodextrin ratio, as well as the effects of drying temperature and time. Validation results underscored the model reliability, exhibiting narrow standard deviations ranging from 0.001% to 1.3%. These outcomes emphasise the efficacy of Response Surface Methodology (RSM) and Central Composite Design (CCD) in refining formulations, offering valuable insights into appropriate product development and a seamless scale-up process.

Effect of different forms of buckwheat addition on the physicochemical and sensory properties of breadOriginal Paper

Erdi Eren, Murat Reis Akkaya

Czech J. Food Sci., 2024, 42(3):216-223 | DOI: 10.17221/36/2024-CJFS

This study aimed to obtain buckwheat bread by adding whole buckwheat to the white bread formulation in groat and flour form. The addition was made in different proportions (0, 10, 20, and 30%) according to the principle of substitution. Buckwheat addition, as groat, increased the bread's hardness to a great extent. Moisture analysis results indicated that the buckwheat additive can increase the water-holding capacity and may extend the shelf life, especially in flour form. The samples' antioxidant activities and phenolic content significantly increased when the addition was made as flour. All buckwheat-added samples had lower volume values than control samples. Buckwheat addition caused an increase in volatile components such as phenylethanol and benzylalcohol. As a result of sensory analysis, using buckwheat as flour and groat positively affected breadmaking. Considering the samples' nutritional and sensory properties, the combination in which 20% buckwheat flour is added to the white bread formulation is the most appropriate use.

Comparative study on quality parameters of dry-cured beaver (Castor fiber) and nutria (Myocastor coypus) sausagesOriginal Paper

Jan Slováèek, ©árka Nedomová, Markéta Janík Piechowiczová, Ondøej Mikulka, Miroslav Jùzl

Czech J. Food Sci., 2024, 42(5):382-389 | DOI: 10.17221/112/2024-CJFS

The aim of the study was to define and compare the quality properties of dry-cured heat-treated meat products from the meat of free-living semi-aquatic wildlife species. Eurasian beaver (Castor fiber) and nutria (Myocastor coypus) are wild animals whose presence in the countryside is regulated in the Czech Republic. Basic chemical, microbiological, sensory analyses, and instrumental measurements of the colour and texture of dry-cured sausages (pork, as a control group with 51% lean pork and experimental groups with 51% lean beaver and nutria meat in fresh state) were performed. There were no statistically significant differences (P > 0.05) in microbiological counts per gram between the sausage groups according to the meat used after 3 weeks of storage. In the sensory analysis, beaver sausages were rated as the darkest and least attractive (P < 0.05). The data obtained using the Meullenet-Owens Razor Shear (MORS) test did not show a statistically significant difference (P > 0.05). However, a significant difference (P < 0.05) was measured between the beaver product and the pork and nutria variants using the compression method.

Green synthesis, characterisation, and antibacterial activity of silver nanoparticles obtained from Salvia officinalis extractOriginal Paper

Nural Karagözlü, Tuğçe Özeºer

Czech J. Food Sci., 2024, 42(3):163-173 | DOI: 10.17221/4/2024-CJFS


The present study investigated the properties and antimicrobial activity of silver nanoparticles synthesised through a green method using Salvia officinalis. Extracts were obtained from sage at two different temperatures, and these extracts were then used to synthesise silver nanoparticles through a reaction with AgNO₃. The characteristics of resulting silver nanoparticles and their antimicrobial effects on foodborne pathogenic bacteria were examined. During the synthesis, the colour of the silver nanoparticle solution changed from yellow to dark brown, and a significant absorbance peak was observed at 360 nm. The sizes of the synthesised silver nanoparticles were found to be 53.77 and 57.08 nm for the two different extraction temperatures, respectively. The nanoparticles exhibited spherical-rod shapes with silver contents of 83.91% and 84.38% and crystal sizes of 37.15 nm and 34.81 nm, corresponding to the two temperatures. The reduction of silver ions involved functional groups like C=C or C=O. The antimicrobial activity of the synthesised silver nanoparticles was evaluated at concentrations of 10 and 25 mg·mL–1 using the paper disc method against several foodborne pathogenic bacteria. Notably, the sage extract displayed antimicrobial efficacy against Salmonella Typhi, Listeria monocytogenes, and Staphylococcus aureus. However, no significant antimicrobial effect was observed against Escherichia coli O157:H7.

Analysis of the quality of curds from Slovakia and neighbouring countriesOriginal Paper

Jana Záhumenská, Franti¹ek Zigo, Tomá¹ Mihok, Mariana Kováèová, Zuzana Farka¹ová, Jana Výrostková, Zuzana Lacková, Mária Vargová

Czech J. Food Sci., 2024, 42(5):317-329 | DOI: 10.17221/51/2024-CJFS

The work deals with the evaluation of the quality of curds produced in Slovakia and neighbouring countries (Czech Republic, Poland, Hungary, Ukraine) at the time of their purchase and at the time of the end of the warranty period. Significant differences in consistency (P < 0.05) were found between the model samples of cottage cheese after sensory evaluation. Differences in total porosity were noted between curds examined on the first and last day, storage reduced porosity and changed (reduced) grain size. There was a significant difference in colour between the samples (A1–E5) (P < 0.05). Colourimetric measurement confirmed the lightest colour in sample E4 (L* = 92.87, L* – lightness) from Ukraine, which showed the lowest fat content, and the darkest sample was sample C3 from Poland (L* = 88.62). The minimum value of dry matter content was found in sample E4 (15.79 ± 2.59%) and the maximum value in sample C3 (35.82 ± 2.59%). Towards the end of the use-by date, the dry matter values slightly decreased. Statistical significance was demonstrated between the first day of purchase and the expiration date in dry matter content (P < 0.05) and between fat content in dry matter (< 0.05). The titration acidity was exceeded in two cases, in sample B2 (first day – FD 172 °SH / last day – LD 192 °SH) and B4 (FD 162 °SH / LD 167 °SH). During the guarantee period, the growth of micromycetes in curds was statistically significant (P < 0.05).

Enhancement of semolina pasta with carob molasses pulpOriginal Paper

Serpil Yalim Kaya, Sevcan İlhan, Özlem İstanbulu Paksoy

Czech J. Food Sci., 2024, 42(2):109-117 | DOI: 10.17221/152/2023-CJFS

This study aimed to determine the effect of carob molasses pulp flour (CMP) at 5.0, 7.5, and 10.0% on the chemical composition and properties of eggless semolina pasta in terms of colour, nutritional value, cooking quality, and sensory properties. As presumed, carbohydrate and energy values of CMP-added pasta (carbohydrates 73.31–77.40%) were lower than the control (82.17%), whereas dietary fibre values were up to 4 times higher (8.18–12.60% vs. 3.71%). There was not a significant difference in the amount of fat (0.48–0.70%), optimum cooking time (6.56–7.06 min), or cooking loss (10.43–12.57%) of CMP-added pasta compared to the non-enriched counterpart (> 0.05). All formulations were sufficient in terms of sensory properties; colour shift occurred in the direction from standard yellow to the dark brown area. The results showed that even the maximal tested dosage of the CMP equal to 10.0% could produce pasta with satisfying overall quality.

Effect of the disinfectant benzalkonium chloride on Listeria monocytogenes biofilmOriginal Paper

Chao Yang, Xiaochen Zhang, Tao Yu, Lin Wang, Zichuan Zhu, Xinjie Fan

Czech J. Food Sci., 2024, 42(4):295-304 | DOI: 10.17221/44/2024-CJFS


Listeria monocytogenes is capable of forming biofilms on the food contact surfaces, increasing the risk of food contamination by this pathogen. The disinfectant benzalkonium chloride (BC) is commonly used to control L. monocytogenes in the food industry. This study aimed to investigate effects of BC on L. monocytogenes biofilms. Biofilm biomass was measured by the microplate method with crystal violet staining. Results from the broth microdilution method showed that the minimum inhibitory concentration (MIC) of BC against L. monocytogenes 10403S was 8 μg·mL–1. Sub-MICs of BC inhibited the biofilm formation and lethal concentrations of BC removed mature biofilms of L. monocytogenes 10403S. The presence of BC reduced extracellular proteins and exopolysaccharides in biofilms. Additionally, upregulation of quorum sensing gene luxS and agrBDCA and downregulation of flagellum motility genes flaA, motA, and motB were observed in the presence of BC. The BC disinfectant has an excellent anti-biofilm activity against L. monocytogenes.

Prebiotic and antioxidant effects of the extracts from fruits and flowers of Cereus hildmannianusOriginal Paper

Everton da Silva Santos, Gabriela Krausová, Ivana Hyr¹lová, Maria de Fátima Pires da Silva Machado, Arildo José Braz de Oliveira, Gizem Özlük, Regina Aparecida Correia Gonçalves

Czech J. Food Sci., 2024, 42(6):415-422 | DOI: 10.17221/128/2024-CJFS


Cereus hildmannianus is a species with various nutritional and medicinal properties; however, the fruits and flowers have scarcely been explored. In this regard, the study investigated the bioproduction of total sugar content (TSC), total phenolic content (TPC), and total flavonoid content (TFC), antioxidant [DPPH – 2,2-diphenyl-1-picrylhydrazyl and ABTS – 2,2'-azino-bis-(-3-ethylbenzothiazoline-6-sulfonic acid)], iron chelation, and prebiotic activities of methanolic extracts from fruits (epicarps – EE, mesocarps – ME) and flowers (sepals – SE, petals – PE) of C. hildmannianus. The chemical profiles of the extracts were determined by ultra-high-performance liquid chromatography coupled with mass spectrometry. The highest accumulations of TSC were observed in the ME (64%), while the SE also had a high TFC (17 µg QE per mg DW; QE – quercetin equivalents, DW – dry weight) and the EE had a high TPC (646 µg GAE per mg DW; GAE – gallic acid equivalents). A total of 24 compounds (phenolic and organic acids; and glycosylated flavonoids) were putatively identified. The greatest antioxidant activities were obtained with the PE (DPPH: 199 µmol Trolox per mg DW; and ABTS: 59 µmol Trolox per mg DW), while the highest prebiotic effect was obtained with ME and EE regarding both fermentability and production of lactic and acetic acids by multiple species of Lactobacillus and Bifidobacterium. These promising results of bioactive compounds in the fruits and flowers of C. hildmannianus have potential applications for food and pharmaceutical purposes.

Modelling of desorption isotherms for dried meat: New approach and newly applied modelOriginal Paper

Pøemysl Richtr, Josef Bauer, Svatopluk Henke, Rudolf ©evèík

Czech J. Food Sci., 2024, 42(1):55-63 | DOI: 10.17221/170/2023-CJFS


In this paper, desorption isotherms of two jerky products were studied (whole-muscle jerky – sample 1 and minced jerky – sample 2). The work focused on the comparison of the Dynamic Dewpoint Isotherm (DDI) method and the Saturated Salt Slurry (SSS) method and testing the newly applied model for modelling desorption isotherms for dried meat. Data were statistically processed using 8 models [Guggenheim-Anderson-de Boer (GAB), Double Log Polynomial (DLP), Henderson, Chin, Smith, Oswin, Hasley, and newly applied model] and statistically evaluated using coefficient of determination (R2), root mean squared error (RMSE) and mean relative percentage deviation (P-value). The DLP model (25 °C) reached R2 ≥ 0.999, P-value ≤ 1.84 for DDI, and R2 ≥ 0.998, P-value ≤ 4.37 for SSS method. The GAB model reached R2 ≥ 0.997, P-value ≤ 2.58 for DDI, and for SSS method the GAB model reached R2 ≥ 0.998, P-value ≤ 5.47. The new model reached P-value ≤ 5.73 for DDI and P-value ≤ 3.48 for SSS method. All models reached the P-value < 10% except for Smith and Chin models. The DDI method and newly applied model prove to be a suitable and precise approach to the evaluation of isotherms of dried meat products.

Chokeberry (Aronia melanocarpa) as natural antioxidant for the meat industryOriginal Paper

Andrea Mesáro¹ová, Marek Bobko, Luká¹ Jurèaga, Alica Bobková, Katarína Poláková, Al¾beta Demianová, Judita Lidiková, Ondøej Buèko, Andrea Mendelová, Tomá¹ Tóth

Czech J. Food Sci., 2024, 42(3):184-191 | DOI: 10.17221/38/2024-CJFS

Aronia melanocarpa is one of the many fruit types rich in polyphenolic compounds. Therefore, we used this fruit in our research as a possible natural antioxidant, which was added to pork sausages. Four groups were prepared: control group, a group with ascorbic acid, and groups with 3 and 5 mL·kg–1 of chokeberry extract. During storage, we monitored changes in pH, colour, texture and oxidative stability of pork sausages and sensory evaluation. We did not observe any negative effects of the extract on the quality of pork sausages during storage. Regarding oxidative stability, the lowest increase in malondialdehyde (MDA) was observed in the group with 5 mL·kg–1 of chokeberry extract, which was comparable to the group with ascorbic acid.

Nanocellulose as a fat substitute to improve the quality of emulsified sausages: Effects of morphology and contentOriginal Paper

Hongzhen Guo, Xiaolan Shang, Yunping Cheng, Qiuling Li

Czech J. Food Sci., 2024, 42(5):364-371 | DOI: 10.17221/114/2024-CJFS

Two different morphologies of nanocellulose – cellulose nanofibres (CNFs) and cellulose nanocrystals (CNCs) with different contents were added to emulsified sausages to replace pork back fat in different proportions (10%, 30%, and 50%), and the colour, emulsion stability, texture characteristics and dynamic rheological behaviour of emulsified sausages were analysed. The results indicate substituting fat with nanocellulose led the L* (lightness) and a* (redness) values increased and the b* (yellowness) values decreased of the emulsified sausages. Increasing nanocellulose concentration improved the emulsion stability of the sausages. In terms of emulsion stability, the use of CNFs outperformed CNCs, especially for samples substituted with 50% fat. In terms of texture, emulsified sausages where CNCs replaced fat showed lower hardness, viscosity, and chewiness compared to those with CNFs. The dynamic rheological results indicated that when the fat replacement levels were 10% and 30%, samples using CNFs as fat substitute had slightly higher storage modulus (G') values than those using CNCs. However, for 50% fat replacement, samples using CNFs as fat substitute had significantly higher G' values than those using CNCs, which demonstrates that higher CNFs concentrations are more conducive to the formation of a three-dimensional network structure.

Assessing essential oil composition in Cinnamomum cassia leaves from different regions of China using GC-MS and FTIR spectroscopyOriginal Paper

Yan Huang, Yujie Liu, Huiping Tan, Yanrong Cheng, Kunyang Tao, Dingze Gu, Huaizu Cai, Chengjie Li, Kaiyi Guo, Cheng Wu, Hong Wu, Yanqun Li

Czech J. Food Sci., 2024, 42(3):151-152 | DOI: 10.17221/197/2023-CJFS

In this study, volatile compounds from Cinnamomum cassia Presl. leaves from different regions of China were identified using gas chromatography coupled with mass spectrometry (GC-MS) and Fourier-transform infrared (FTIR) spectroscopy combined with chemometrics. The results showed that the essential oil yields greatly varied across regions, with the density of oil cells at the accumulation and saturation stages playing a key role in this yield. GC-MS analysis revealed a higher content of trans-cinnamaldehyde in samples from the Xijiang River basin (No. 1–8) than in those from Baise Guangxi (No. 9). Variable importance in projection analysis identified five differential marker components for assessing the geographical origin of C. cassia leaves: trans-cinnamaldehyde, acetophenone, cis-cinnamaldehyde, camphor, and α-thujene. Hierarchical cluster analysis, similarity evaluation, and principal component analysis from FTIR fingerprinting indicated that essential oil compositions of samples No. 1–6 from the Xijiang River basin were closely related. In contrast, the Baise sample (Western Guangxi) significantly differed from the other eight, likely due to the geographical distance. Our results indicate that the methods employed are effective for determining the geographical distribution and assessing the quality of raw cinnamon in herbal medicine.

Quality characteristics of Hokkaido brown bear meat sauces prepared with rice koji mold and food enzymesOriginal Paper

Azusa Takeda, Masataka Saito, Takeshi Nagai

Czech J. Food Sci., 2024, 42(5):372-381 | DOI: 10.17221/49/2024-CJFS


Hokkaido brown bear (Ursus arctos yesoensis) meats are used as ingredients of game cuisines. In contrast, shank meats are unsuitable as edible meats due to gamy tastes and tough meats. Here, new meat sauces were developed using glutinous rice koji and food enzymes for the application of the underutilised meat i.e. shank meat. The proximate analysis showed that the obtained sauces were reduced-salt sauces at approximately 6.4–7.7 g·(100 g)–1 as salt equivalent. The sauces had a light colour, no unacceptable odours, and strong sweetness and umami taste. The sauce with good sensory acceptability was rich in glutamic acid, leucine, lysine, and alanine. Besides, the essential amino acid contents were remarkably high at approximately 55.6%. In addition, the tested sauces had good antioxidative activities, scavenging activities against reactive oxygen species such as superoxide anion radicals and hydroxyl radicals, and angiotensin I-converting enzyme and hyaluronidase inhibitory activities. These results suggested that Hokkaido brown bear shank meat sauces, which had positive effects for human health, could be used as one of novel condiment with consumer demands.

Influence of the storage duration on the health promoting tyrosine, tryptophan, and total phenolics in potato tubersOriginal Paper

Rita Asakaviciute, Zita Maknickiene

Czech J. Food Sci., 2024, 42(2):93-99 | DOI: 10.17221/161/2023-CJFS

This research investigated the influence of the storage duration on the health promoting tyrosine, tryptophan and total phenolics in potato tubers. In the course of storage, the total amount of accumulated compounds in the dry mass of organically grown potato tubers increases. This is determined by individual properties of potato variety, storage time, and interaction of these two factors (P < 0.05). Organic potato tubers show increased total phenolic compounds in their dry matter during storage. This is due to a variety of characteristics, storage time and the interaction of these two factors (P < 0.05). A more pronounced increase in total phenolic compounds during storage was observed in 2022 than in 2021.

Effect of rosemary and clove essential oils on lipid oxidation, microbial, sensorial properties and storage stability of kavurma, a cooked meat productOriginal Paper

Sezen Harmankaya, Ahmet Harmankaya, Koray ݺbarali, Özlem İstanbullu Paksoy

Czech J. Food Sci., 2024, 42(4):251-262 | DOI: 10.17221/56/2024-CJFS


Kavurma is a traditional cooked meat product of Türkiye containing a high percentage of animal fat (30–40%). Therefore, kavurma can undergo lipid oxidation easily. This may cause a major problem in the storage and marketing of the product. Synthetic additives used in foods cause anxiety in consumers and this situation increases the search for natural alternatives. Plant essential oils can be reliable additives to extend the shelf life of foods. The protective effect of rosemary and clove essential oils on kavurma meat against microbiological and oxidative deterioration was investigated in this study. For this purpose, kavurma samples were divided into five groups after being produced by standard methods, the essential oils (rosemary and clove) obtained by distillation method were added to the kavurma fat in various proportions, alone or in combination. At the end of the study, the thiobarbituric acid-reactive substance (TBARS) and peroxide values of the groups containing plant essential oils were found to be lower than the control groups. The groups containing rosemary and clove essential oil showed that microbiological deterioration was delayed and, the sensory evaluation scores were higher than the control groups at the end of the cold storage period.

Effects of hydroxyl radical oxidation on the structural and functional properties of mutton myosinOriginal Paper

Yingying Cao, Huaiyu Li, Fubing Wang

Czech J. Food Sci., 2024, 42(6):423-434 | DOI: 10.17221/133/2024-CJFS


To research the impact of free radical oxidation on myosin, we established a hydroxyl radical oxidation system using iron/hydrogen peroxide/ascorbic acid. By varying hydrogen peroxide concentrations (0, 0.5, 1, 5, 10, 20 mmol·L–1), we achieved different oxidation levels of myosin and investigated the effects on its structural and functional characteristics. The results showed that when the H2O2 concentration was 20 mmol·L–1, compared with the control group, the carbonyl content of myosin was 2.376 times higher, the sulfhydryl content was decreased by 37.02%, the surface hydrophobicity was increased by 59.13%, the solubility was decreased by 19.54%, and the turbidity was significantly increased (P < 0.05). Myosin emulsification, emulsification stability, and foaming capacity initially increased and then they diminished, and the maximum value was reached when the H2O2 concentration was 5 mmol·L–1, whereas foaming stability remained relatively unchanged. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis research revealed increased crosslinking and protein polymerisation in oxidised myosin. The secondary structure of myosin measured by Fourier infrared spectroscopy showed that the α-helix content decreased by 14.41% and the β-fold content increased by 44.50%. These results suggested that oxidative modification alters the structural and functional properties of myosin, providing valuable insights for its structural and functional analyses.

Study of substitution of beef and tapioca flour with tuna meat and purslane flour on meatball qualityOriginal Paper

Nafly Comilo Tiven, Tienni Mariana Simanjorang

Czech J. Food Sci., 2024, 42(1):64-70 | DOI: 10.17221/196/2023-CJFS


Tuna meat (Thunnus atlanticus – blackfin tuna) and purslane flour (Portulaca oleracea L.), which contain high protein and polyunsaturated fatty acids but are low fat and cholesterol, are used to substitute beef and tapioca flour to produce quality meatballs. This study aims to determine the effect of substituting beef and tapioca flour with tuna meat and purslane flour on meatballs' chemical, physical, and sensory quality. The beef was substituted with 40% tuna meat, and tapioca flour was substituted with 0, 10, and 20% purslane flour. The data obtained were analysed using a complete randomised design, with three treatments and five replications, respectively, and further tested with the Duncan test. The results showed that increasing the level of purslane flour can increase (P < 0.01) the chemical quality (water, protein, fat, ash, and omega-3) but decrease (< 0.01) the cholesterol of the meatballs. Physical quality (water holding capacity and sensory quality (colour) of meatballs were increased (P < 0.01), but taste and acceptability were decreased (< 0.01). It can be concluded that substituting beef and tapioca flour with tuna meat and purslane flour can increase the chemical and physical quality.

Harnessing nature's secrets: Silver nanoparticles from Withania coagulans fruit and root extracts unveil exceptional antioxidant and antimicrobial propertiesOriginal Paper

Farwa Iftikhar, Rahmatullah Qureshi, Ayesha Siddiqa, Khursid Anwar, Fizza Arshad, Zia-ur-Rehman Mashwani, Aayesha Riaz, Safir Ullah Khan, Amir Ali, Shahzad Iqbal, Ajaz Ahmad, Melissa Danae Bejarano Gómez

Czech J. Food Sci., 2024, 42(3):192-206 | DOI: 10.17221/39/2024-CJFS

Nanotechnology, an emerging field, holds significant promise with applications across diverse sectors, including medicine, agriculture, and the biological sciences. To address environmental concerns, the green biosynthesis of silver nanoparticles (AgNPs) using plant extracts is favoured. This study focuses on the formulation and characterisation of AgNPs using extracts from Withania coagulans (Stocks) Dunal, a medicinal plant that holds a unique phytochemical profile. The AgNPs derived from W. coagulans root (WcAgNPR) and fruit (WcAgNPF) extracts were characterised using ultraviolet and visible light (UV-Vis) spectral analysis, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and Fourier-transform infrared spectroscopy (FTIR) spectroscopy. The findings reveal that both WcAgNPR and WcAgNPF exhibit substantial antioxidant potential, with robust iron reducing capabilities and potent 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity. Additionally, they demonstrate strong hydrogen peroxide scavenging abilities. Notably, WcAgNPR outperforms WcAgNPF in the phosphomolybdate assay for antioxidant potential. Both AgNPs display remarkable antimicrobial efficacy, with minimal inhibitory concentrations (MIC) below 10 µg·mL–1 against gram-positive bacteria (Staphylococcus aureus) and noteworthy activity against gram-negative Escherichia coli (WcAgNPF with a MIC of 30 µg·mL–1 and WcAgNPR with a MIC of 60 µg·mL–1). These findings highlight the silver nanoparticles' significant antioxidant and antimicrobial potential, suggesting their potential for in vivo use as antimicrobial agents with minimal oxidative damage.

Impacts of exopolysaccharides producing probiotic bacteria on the physicochemical and sensory properties of fermented goat yoghurt under chilled storageOriginal Paper

Han Wu, Xiayidan Maimaiti, Ying Wang, Anthony Pius Bassey, Nurgvl Rahman, Xiaoli Liu

Czech J. Food Sci., 2024, 42(5):305-316 | DOI: 10.17221/125/2024-CJFS

This study focused on the co-fermentation of goat milk with functional lactic acid bacteria (LAB) and traditional yoghurt starter culture. The fermentation process was optimised by single factor experiment and response surface methodology (RSM). The physicochemical and sensory properties of goat milk yoghurt were evaluated under chilled (4 °C) storage for 21 days. The optimised conditions were selected as the inoculum amount of Lactobacillus paracasei NM-8 (1.1 × 107 CFU·mL–1; CFU – colony forming unit), sucrose addition (6.8%) and fermentation temperature (41 °C). During milk coagulation, the pH declined to be 4.45 and the viable LAB number arrived at 8.77 log CFU·mL–1. The content of exopolysaccharides (EPS) increased to be 2.13 g·L–1. These changes led to the better viscosity (941.33–792.33 cP) and higher water holding capacity (63.24–56.20%) of yoghurt fermented using L. paracasei NM-8 in storage, compared with those of yoghurt without L. paracasei NM-8. This study provided a theoretical basis for eliminating the whey precipitation and rough texture of goat milk yoghurt.

Promotional effects on naturally occurring lactic acid bacteria without impairing chickpea germinationOriginal Paper

Eli¹ka Kováøíková, Veit Ny, Miloslav ©ulc, Jana Rysová, Natálie Peèenková, Milan Hou¹ka

Czech J. Food Sci., 2024, 42(2):85-92 | DOI: 10.17221/12/2024-CJFS


Sprouting has been used widely to enrich the nutritional quality of cereals and legumes. It improves the bioavailability of nutrients, especially those bound to phytic acid. However, sprouting is a good medium for microbial growth; thus, producing safe sprouts from harmful microbial growth is challenging. In food biotechnology, lactic acid bacteria (LAB) can be potentially used to improve nutrition and play a vital role as competitive microbes in food preservation. Therefore, supporting natural LAB growth by adding glucose sources during sprouting can produce a safer sprouting medium. Chickpeas (Cicer arietinum L.) sprouted for up to 50 h with glucose (0.1% and 1%) under aero-anaerobic conditions, with recycled water periodically spraying on the sprouts to support the natural LAB growth. Results show increased LAB counts, lactic acid and acetic acid, and decreased pH. Moreover, the addition of glucose had no significant detrimental effects on sprout quality compared to the control sample relative to nutritional compounds, such as saccharides, which remained similar. This sprouting method can be scaled up to production levels and is considerably cheaper than other treatments.

Comprehensive nutritional profiling and antioxidant capacity assessment of indigenous mushrooms Pleurotus ostreatus and Agaricus bisporusOriginal Paper

Touseef Iqbal, Muhammad Sohaib, Sanaullah Iqbal, Habib Rehman

Czech J. Food Sci., 2024, 42(3):174-183 | DOI: 10.17221/158/2023-CJFS


The global demand for high-quality, nutritious food is increasing, and mushrooms have gained popularity as a healthy dietary option; mushroom consumption is increasing in Pakistan owing to their rich nutritional profile, phytochemicals presence and antioxidant capacity. This study was carried out to determine comprehensive nutritional analysis, antioxidant parameters, amino acids, and fatty acid composition of commonly grown mushroom varieties oysters (Pleurotus ostreatus) and white buttons (Agaricus bisporus) in Pakistan. The study results indicated mushrooms are perishable, high in protein and fibre content, along with a low caloric value. Also, they are rich in essential minerals like potassium, phosphorus, iron, and water-soluble vitamins. In addition, both mushrooms demonstrated significant antioxidant activity, with oyster mushrooms having a higher potential. Additionally, profiling of fatty acids and amino acids showed mushrooms having low caloric value and powerful nutrition composition that makes them suitable for developing healthy dietary choices for better human health.

The relationship between large deformation rheology of wheat flour dough with protein quantity and aggregate stretching degree of milling streams flour based on regression analysisOriginal Paper

Ziyan Dong, Ting Su, Meiyao Dai, Clyde Don, Boli Guo, Shuangkui Du, Bo Zhang

Czech J. Food Sci., 2024, 42(5):353-363 | DOI: 10.17221/64/2024-CJFS

The aim of this study was to compare the role of protein quantity and aggregate stretching degree in predicting dough stability and extensibility using the regression analysis, and to explore a more effective way of conducting the prediction. Flours from 28 milling streams of the wheat cultivar Shiluan 02-1 were collected as experimental material. Using the value of (ash content/L*) (L* – lightness), we sorted the milling streams flour from the inner layer to the outer layer of wheat kernel, which was divided into early reduction, later reduction, and break flours. Three regression models, quantity-based, stretching-degree-based and (quantity × stretching-degree)-based model for predicting dough stability and extensibility were evaluated in each category of milling streams through their coefficient of determination (R2). Certain patterns were observed in physicochemical properties of flour from different categories of milling streams. Despite those considerable changes, the quantity-based model broadly produced greater R2 values than the stretching-degree-based model, and the (quantity × stretching-degree)-based model could in general provide higher R2 values than the other two models on predicting dough stability and extensibility. The results suggest that measuring the protein quantity and aggregate stretching degree at the same time is of practical improvement in dough rheology evaluation, compared to focusing on either factor alone.

A frontier approach for the production of enteric soft capsules containing omega-3 fatty acids and probioticsOriginal Paper

Hayoung Kim, Won Yeong Bang, Boyoung Choi, Han Bin Lee, Jungwoo Yang

Czech J. Food Sci., 2024, 42(2):127-135 | DOI: 10.17221/181/2023-CJFS


The study investigated whether omega-3 fatty acids could promote bacterial growth, acid and bile tolerance, and cell adhesion onto Caco-2 cells to develop a multifunctional enteric soft capsule containing probiotics and omega-3 fatty acids. The probiotic strains used were Enterococcus faecium IDCC 2102 and Bacillus coagulans IDCC 1201. Supplementation with omega-3 fatty acids did not significantly affect the growth and viability of either strain at lower concentrations (i.e. 0.5–1.0 w/w %). In comparison, the adhesion ability to Caco-2 cells of both strains was significantly increased (up to 107.5%). Furthermore, Bacillus coagulans IDCC 1201 [1 × 1010 CFU (colony forming unit) per capsule] contained together with omega-3 fatty acids (600 mg per capsule) in the enteric soft capsules showed a stability of over 95% during 12 months of storage at room temperature, which was similar to that of unencapsulated lyophilised probiotics. Thus, these results indicate that multifunctional food supplements in the form of enteric soft capsules are feasible.

Phytochemical, antioxidant activity, and thermal stability of Clitoria ternatea flower extractsOriginal Paper

Sy-Yu Shiau, Yuhan Wang, Yanli Yu, Songling Cai, Qian Liu

Czech J. Food Sci., 2024, 42(4):284-294 | DOI: 10.17221/68/2024-CJFS


The demand for beneficial, safe natural pigments is growing. Clitoria ternatea (CT) flowers are a promising source of natural blue colours and bioactive compounds. This study extracted intact CT flowers (CTFs) and their powders (CTFPs) with distilled water at various temperatures (30–90 °C) and durations (30–180 min). The total anthocyanin content (TAC) and total phenolic content (TPC) of the CT extracts were analysed by using the pH differential and Folin-Ciocalteu methods, respectively. The antioxidant activity was expressed as the ability to scavenge DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals. The results showed that different sample types significantly (P < 0.05) influenced the TAC, TPC, and antioxidant activity. The optimal TAC and TPC extraction for CTF was at 90 °C for 90 min, and for CTFP at 90 °C for 30 min. Using hot water instead of 60% alcohol organic solvent was feasible for extracting the phytochemicals, particularly with CTF. Ultrasound-assisted extraction was notably effective for anthocyanins from intact flowers. Higher heating temperatures and pH values increased the anthocyanin degradation rate constants, while a higher pH decreased the activation energy. Thus, blue aqueous CT flower extracts, rich in phytochemicals and antioxidants, have the potential for use in foods and nutraceuticals with neutral and acidic pH values.

Diversity of cultivable lactic acid bacteria and bacilli in traditional fermented foods in VietnamOriginal Paper

Giang Phan Thi Hang, Markéta Husáková, Petr Ka¹tánek, Petra Patakova

Czech J. Food Sci., 2024, 42(6):435-446 | DOI: 10.17221/162/2024-CJFS


Lactic acid bacteria (LAB) are commonly used in many European and Asian traditional fermented foods such as yogurt, cheese, sourdough, meat, fruit, vegetables, cereal products, sour spring rolls, fish sauce, sour shrimp, chao, ruou nep, tofu. They not only improve the flavour and texture of fermented products but also they inhibit the development of spoilage bacteria as antimicrobial agents. In this study, thirty-five traditional Vietnamese fermented products were collected for isolation, identification, and characterisation of LAB and bacilli. There were fifty-three species of LAB isolated from samples such as Lactococcus lactis, Lactiplantibacillus plantarum, Limosilactobacillus fermentum, Liquorilactobacillus nagelli, Companilactobacillus farciminis, Levilactobacillus brevis, Lactiplantibacillus pentosus, Lactococcus garvieae, Lactilactobacillus sakei, and twenty-one species of bacilli such as Priestia megaterium, Bacillus cereus, Bacillus pumilus, Metabacillus indicus. This study aimed to provide information about the occurrence of LAB and bacilli in traditional fermented foods in Vietnam and their brief characterisation.

Effect of debranching enzyme hydrolysis and microwave treatments on the resistant starch enrichment of breadfruitOriginal Paper

Thanh Le, Trang Tran, Tuyen Kha*

Czech J. Food Sci., 2024, 42(1):1-9 | DOI: 10.17221/136/2023-CJFS


Breadfruit's substantial carbohydrate content makes it a viable starch source, specifically resistant starch (RS) that helps prevent chronic diseases. This study investigated the effects of enzyme hydrolysis and microwave treatment (MT) on enriching type III RS in breadfruit. It also determined its structural and functional properties, including swelling power, solubility index, water absorption capacity, oil binding capacity, and syneresis. MT at 30 W·g–1 for 3 min resulted in the highest RS content of 74.8%, significantly surpassing pullulanase hydrolysis (1.0 U·g–1 dry basis for 12 h) at 17.3% RS. The breadfruit starch granules exhibited a regular shape, approximately 7.9 µm in length, whereas modified granules were less than 11 µm, along with observable deformation in their structural shape. In conclusion, the study demonstrates the efficacy of MT for enhancing RS content in breadfruit, highlighting its potential as a healthy functional ingredient and starch substitute.

Cup viscometer – A practical analytical toolShort Communication

Milan Hou¹ka

Czech J. Food Sci., 2024, 42(1):71-76 | DOI: 10.17221/159/2023-CJFS


This paper focuses on helping smaller companies in the manufacturing industry who need to know the viscosity of their products or raw materials and do not have the funds to invest in expensive rotary rheometers. We developed a calibrated simple cup. It has replaceable nozzles designed so that dripping liquids cannot distort discharge times. The calibration of the cup is based on the relationship between kinematic viscosity and outflow time, which is valid for the laminar flow regimes. Here we described calibration and measurement procedures and methods for detecting non-Newtonian flow behaviour and the viscoelasticity of measured liquids. The maximum measurement error of 3% is defined for cases where all distractions are removed.

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