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Results 151 to 180 of 583:

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

Monika Tomczyk, Maria Tarapatskyy, Ma³gorzata D¿ugan

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 and FRAP tests, as well as photochemiluminescence method). Moreover, total phenolics compounds and flavonoids content were determined. The most significant differences (P < 0.05) between Polish and Slovak counterparts were found for tilia while the lowest for rape honeys. The impact of geographical origin on overall quality of honey was proved by PCA statistical tool.

Palm date (Phoenix dactylifera) seeds: A rich source of antioxidant and antibacterial activitiesOriginal Paper

Abuelgassim Omer Abuelgassim, Mohamed Abdellatif Eltayeb, Farid Shokry Ataya

Czech J. Food Sci., 2020, 38(3):171-178 | DOI: 10.17221/269/2019-CJFS

Two varieties of palm date seeds (PDS), Sukkari and Khalas, were examined for their antioxidant and antibacterial activities. Total phenol content was 2 014.37 ± 212.05 and 2 060.40 ± 176.0 mg GAE 100 g-1 dry weight (DW); and total flavonoid content was 83.98 ± 1.10 and 94.97 ± 1.36 mg QE 100 g-1 DW for Sukkari and Khalas, respectively. PDS extracts showed potential scavenging activity against ABTS, DDPH, and hydroxyl radical; the calculated IC50s were 431.17 ± 12.45, 400 ± 10.87 and 680 ± 18.12 µg for Sukkari, and 476 ± 20.25, 302.24 ± 14.08 and 284.18 ± 11.62 µg for Khalas, respectively. PDS extracts did not show potential activity against superoxide anion. Both extracts showed a high percentage of reducing power as the calculated FRAP (ferric reducing antioxidant power) concentrations were 12.66 ± 1.08 and 16.14 ± 1.94 mmol ascorbic acid equivalent 100 g-1 for Sukkari and Khalas, respectively. Bacillus subtilis showed a remarkable sensitivity to PDS extracts; the inhibition zones were 21 ± 0.82 and 22 ± 0.67 mm for Sukkari and Khalas, respectively. PDS extracts possess good antioxidant and antibacterial activity, and therefore PDS could be effectively used as a natural source of antioxidants and to be detected against gram-positive bacteria.

Phloridzin as a marker for evaluation of fruit products authenticityOriginal Paper

Magdaléna Hrubá, Josef Baxant, Helena Èí¾ková, Veronika Smutná, Franti¹ek Kovaøík, Rudolf ©evèík, Kristýna Hanu¹ová, Ale¹ Rajchl

Czech J. Food Sci., 2021, 39(1):49-57 | DOI: 10.17221/239/2020-CJFS

Abstract: Phloridzin (phloretin-2'-O-glucoside) is a phenolic compound characteristic of the genus Malus. This study aimed to evaluate phloridzin as a marker of undeclared addition of apples in fruit products. To test this proposal, the heat and oxidation stability of phloridzin was firstly confirmed. Then the distribution and variability of phloridzin in apples were studied, showing no difference between the tested apple varieties (Golden Delicious, Granny Smith, Rubin and Champion) but a significant difference in phloridzin content in seeds (2 380 ± 755 mg kg-1) compared to peel, flesh and core, which contained less than 70 mg kg-1. The effects of different stages of apple purée production at an industrial scale were also investigated. The kinetics of phloridzin diffusion from seeds to apple homogenate played an important role in the final phloridzin content in 16 analysed apple purées (26-39 mg kg-1). Finally, the survey of phloridzin content in 31 fruit products in the market was carried out. Phloridzin was also measured in eight jams and fillings which did not declare the presence of apples on their labels; findings from 2 to 6 mg kg-1 indicate the addition of apples from 5% to 20%. It was confirmed that phloridzin appears to be a suitable marker for detecting the undeclared presence of apples, which are a cheap substitute for the declared fruit types.

Chemical, nutritional, and bioactive compositions of fresh, washed, and blanched shiitakeOriginal Paper

Jeng-Leun Mau, Jim Tseng, Cheng-Rong Wu, Chien-Hung Chen, Sheng-Dun Lin

Czech J. Food Sci., 2021, 39(6):426-434 | DOI: 10.17221/214/2020-CJFS

Washing and blanching are two important steps for the processing of fresh good grade small shiitake into casual snacks and prepared foods. This study explored their effects on the dimensions, weights, proximate compositions, taste and bioactive compounds of the shiitake caps and stipes. Results showed that the dimensions and weights of the caps and stipes increased after washing but decreased after blanching. On a dry basis, washing did not affect the nutrients and bioactive compounds contents of shiitake except sugars and polyols compared to fresh samples. However, blanching greatly reduced all the quality contents of the shiitake. The major minerals in the caps and stipes were potassium, magnesium and calcium. The main polyol, sugar, free amino acid, and 5'-nucleotide of shiitake were mannitol, trehalose, glutamine and 5'-adenosine monophosphate, respectively. Equivalent umami concentration (EUC) in the caps was three-fold higher than that in the stipes. Ergosterol, ergothioneine, γ-aminobutyric acid (GABA), and total phenols contents in the caps were significantly higher than those of the stipes, but the polysaccharides showed the reversed. Overall, both caps and stipes contain the necessary nutrients and bioactive compounds, and the blanching significantly affected the above-mentioned components of all tested samples.

Isolation of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus from nature: Technological characterisation and antibiotic resistanceOriginal Paper

Hakan Tavsanli, Tülay Elal Mus, Figen Cetinkaya, Ergün Ayanoglu, Recep Cibik

Czech J. Food Sci., 2021, 39(4):305-311 | DOI: 10.17221/296/2020-CJFS

Yoghurt fermenting bacteria were isolated from natural sources including plants, dew, and rain samples (total of 300 samples) by the same methods nomadic peoples used for several centuries in Turkey. Inoculation into the reconstituted skim milk followed by planting on specific media and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) analysis allowed for the identification of 18 Lactobacillus delbrueckii subsp. and 26 Streptococcus thermophilus. A multiplex polymerase chain reaction (PCR) assay applied to lactobacilli enabled the identification of 5 isolates as L. delbrueckii subsp. bulgaricus. The isolates showed a varying range of acidification rates and proteolytic activity in reconstituted skimmed milk (RSM). S. thermophilus isolates showed a broader range of resistance and the most frequent resistance was observed for streptomycin (69.2%), gentamycin (65.3%), clindamycin (61.5%), ampicillin (61.5%), kanamycin (53.8%), and erythromycin (50%). For L. delbrueckii subsp. the highest resistance was determined for vancomycin (38.8%), ciprofloxacin (33.3%), and penicillin (27.8%). The frequency of multiple resistance was tested on 14 different antimicrobials determining that 19 S. thermophilus (73%) and 3 L. delbrueckii subsp. (16.7%) demonstrated resistance to more than three different antibiotics. In contrast to this wide-ranging resistance, five isolates from each genus were found to be susceptible to all tested antibiotics. The present study indicates that lactic acid bacteria (LAB) isolated from nature may have broad-range of resistance to antibiotics and could be a source for the transfer of resistance.

Challenging the problematic detection of clostridial isolates causing late-blowing defect with MALDI–TOF MSOriginal Paper

Pelin Ertürkmen, Zübeyde Öner

Czech J. Food Sci., 2023, 41(1):36-43 | DOI: 10.17221/199/2022-CJFS

The present study aimed to evaluate the Clostridium spp. counts in corn silage, raw milk and Kaºar cheese and to identify the clostridial isolates causing a late-blowing defect (LBD) potential using matrix-assisted laser desorption-ionization-time of flight mass spectrometry (MALDI-TOF MS). Lactate-fermenting clostridial spores (LFCS) were determined by the most probable number method (MPN) in 14 samples of corn silage, 12 samples of raw milk and 20 samples of Kaºar cheese. 181 isolates were obtained from MPN gas-positive tubes. Gram staining, catalase and oxidase activity, anaerobic development tests and Scanning Electron Microscopy (SEM) imaging showed that 95 isolates were typical clostridial bacteria. Sixty-six isolates could maintain viability during the passage and stock stages. A confirmatory identification technique was then performed using MALDI-TOF MS. The results revealed that (49 out of 66 isolates) of bacteria were correctly identified as 38 (77.55%) Clostridium sporogenes, 6 (12.24%) Clostridium butyricum, 3 (6.12%) Clostridium beijerinckii, 1 (2.04%) Clostridium bifermentans and 1 (2.04%) Clostridium sartagoforme. This study determined that clostridial isolates that cause LBD can be identified successfully and quickly by MALDI-TOF MS, a novel method for detecting anaerobic bacteria.

Sensitivity of Listeria innocua to high hydrostatic pressure at low temperature in Ringer's solution and milkOriginal Paper

Osman Erkmen

Czech J. Food Sci., 2023, 41(3):189-195 | DOI: 10.17221/121/2022-CJFS


The research was performed to investigate the effect of high hydrostatic pressure low temperature (HHPLT) on Listeria innocua in Ringer's solution (RS) and raw milk (RM). The physicochemical properties of RM were studied at 300 MPa and 10 °C. Compared with the control, protein and lipase activities were reduced at HHPLT in RM. The L-values (luminance) of LHPLT applied RM were significantly (< 0.05) decreased for colour Pressure application at 300 MPa for 90 min totally inactivated L. innocua at –20 °C in both RS and RM. L. innocua showed resistance to low pressure (200 MPa) in RM. Overall, increasing the pressure with applications at –20 and –30 °C resulted in a higher (< 0.05) inactivation of L. innocua than at 10 and 20 °C. HHPLT applications to frozen RM resulted in the retention of textural characteristics.

Classification of hazelnuts according to their quality using deep learning algorithmsOriginal Paper

Nizamettin Erbaº, Gökalp Çinarer, Kazim Kiliç

Czech J. Food Sci., 2022, 40(3):240-248 | DOI: 10.17221/21/2022-CJFS

Hazelnut is a product with high nutritional and economic value. In maintaining the quality value of hazelnut, the classification process is of great importance. In the present day, the quality classification of hazelnuts and other crops is performed in general manually, and so it is difficult and costly. Performing this classification with modern agricultural techniques is much more important in terms of quality. This study was based on a model intended to detect hazelnut quality. The model is about the establishment of an artificial intelligence-based classification system that can detect the hidden defects of hazelnuts. In the developed model, the visuals used in the dataset are divided into training and test groups. In the model, hazelnuts are divided into 5 classes according to their quality using AlexNet architecture and modern deep learning (DL) techniques instead of traditional hazelnut classification methods. In this model developed based on artificial intelligence, a very good approach was presented with the accurate classification of 99%. Moreover, the values regarding precision and recall were also determined at 98.7% and 99.6%, respectively. This study is important in terms of becoming widespread information technology use and computer-assisted applications in the agricultural economics field such as product classification, quality, and control.

Determination of some heavy metals in different wheat flour brands in Sulaimani, Kurdistan Region – IraqOriginal Paper

Muhammad Faruq Wahab, Dara Muhamed Jamil

Czech J. Food Sci., 2023, 41(6):455-461 | DOI: 10.17221/85/2023-CJFS

Wheat flour is one of the most important sources of nutrients, and it is widely consumed worldwide as a raw ingredient in bread and other pastries. High heavy metal concentrations in the consumed wheat products could induce higher health risks. This study evaluated the heavy metal concentrations in the most available foreign and domestic wheat flour in Sulaimani, Kurdistan Iraq. The wheat flour samples were collected from different locations, and the heavy metal concentration was measured by inductively coupled plasma optical emission spectrometry (ICP-OES). The mean values in wheat flour samples were roughly within the permissible limit set by Iraqi standard (IQS), GCC Standardization Organization (GSO) (GCC – Gulf Cooperation Council), Codex, and FAO/WHO. Heavy metals were detected in the descending order copper (Cu) > lead (Pb) > arsenic (As) > chromium (Cr) > nickel (Ni) > cadmium (Cd) > cobalt (Co). The results showed that wheat flour samples from the Sulaimani markets were slightly contaminated with Ni, and one domestic wheat flour sample with Pb was probably linked to fertiliser and soil contamination. It is concluded that wheat flour could be a source of chronic exposure to toxic heavy metals such as nickel and lead, resulting in adverse health issues later. Consequently, regular monitoring of soil contamination, water quality, and use of recommended levels of fertilisers and pesticides in the agricultural areas of Sulaimani are recommended.

Rapid non-destructive identification of selenium-enriched millet based on hyperspectral imaging technologyOriginal Paper

Fu Zhang, Xiahua Cui, Chaochen Zhang, Weihua Cao, Xinyue Wang, Sanling Fu, Shuai Teng

Czech J. Food Sci., 2022, 40(6):445-455 | DOI: 10.17221/129/2022-CJFS

To meet rapid and non-destructive identification of selenium-enriched agricultural products selenium-enriched millet and ordinary millet were taken as objects. Image regions of interest (ROI) were selected to extract the spectral average value based on hyperspectral imaging technology. Reducing noise by the Savitzky-Golay (SG) smoothing algorithm, variables were used as inputs that were screened by successive projections algorithm (SPA), competitive adaptive reweighted sampling (CARS), uninformative variable elimination (UVE), CARS-SPA, UVE-SPA, and UVE-CARS, while sample variables were used as outputs to build support vector machine (SVM) models. The results showed that the accuracy of CARS-SPA-SVM was 100% in the training set and 99.58% in the test set equivalent to that of CARS-SVM and UVE-CARS-SVM, which was higher than that of SPA-SVM, UVE-SPA-SVM, and UVE-SVM. Therefore, the method of CARS-SPA had superiority, and CARS-SPA-SVM was suitable to identify selenium-enriched millet. Finally, 454.57 nm, 484.98 nm, 885.34 nm, and 937.1 nm, which were obtained by wavelength extraction algorithms, were considered as the sensitive wavelengths of selenium information. This study provided a reference for the identification of selenium-enriched agricultural products.

Nutritional composition analysis and quality evaluation of cattle in different regions of Guizhou Province (China)Original Paper

HaoXiang Xu, WenJu Luo, Lu Lei, JiuLing Long, Bo Yu, YuanFeng Zhao, Rong Ai, Jiang Lingling, Jiang Ran, JingRui Zhou (email: 296655827@qq.co

Czech J. Food Sci., 2023, 41(6):455-472 | DOI: 10.17221/133/2023-CJFS

This study aimed to investigate the variations in nutritional composition among different breeds of cattle in Guizhou. Specifically, this study selected Guanling, Weining, Sinan, Wuchuan, and Simmental cattle as experimental subjects. Assessing the nutritional quality of the longissimus dorsi muscle involves evaluating various parameters, including ultimate pH (pHu), meat colour, water-holding capacity, shear force, protein and fat content, levels of organic acids and amino acid composition. The study's findings indicated notable variations among the muscles of different cattle breeds tested. Guanling, Wuchuan, and Simmental cattle exhibited the highest water-holding capacity, while Wuchuan cattle displayed the highest shear forces. Guanling cattle and Simmental cattle had the highest levels of protein and fat. Weining cattle and Simmental cattle demonstrated the highest concentrations of lactic acid and oxalic acid. Guanling cattle exhibited the highest total amino acid and essential amino acid content. Moreover, Guanling cattle and Weining cattle showed the highest lightness (L*) and yellowness (b*) values, indicating lighter meat colour, while Weining cattle had the highest redness (a*) value, indicating redder meat colour. No significant differences among the five cattle breeds were observed in pHu and propionic acid content. These results provide a theoretical basis and serve as a data reference for assessing the suitability of different beef varieties for various processing purposes.

Food safety inspection of tas kebab and salad processing line in a catering companyOriginal Paper

Gul Ece Soyutemiz, Figen Cetinkaya, Basak Sunguc Cinar, Tulay Elal Mus, Artun Yibar, Merve Dogan

Czech J. Food Sci., 2022, 40(2):147-153 | DOI: 10.17221/142/2021-CJFS

This study was conducted to evaluate the sufficiency of food safety practices in a catering company. The presence of some pathogenic and indicator bacteria was monitored in the samples collected from raw materials, food, food contact surfaces and workers' hands and various steps of the tas kebab (a Turkish meat stew) and salad processing lines. Bacillus cereus was found in ready-to-eat (RTE) tas kebab and RTE salad, while Listeria monocytogenes was isolated from RTE salad. Furthermore, it was observed that RTE salad contained coagulase-positive Staphylococcus aureus without staphylococcal enterotoxin production. The swab samples obtained from cutting board surfaces, knives and workers' hands contained high counts of total aerobic bacteria and some samples were contaminated with coliforms and coagulase-positive/negative staphylococci. The presence of B. cereus and L. monocytogenes in RTE foods is a serious threat to public health, especially in the catering business. Preventing the presence of toxin-producing bacteria in RTE food is a fundamental action. Also, the occurrence of L. monocytogenes in RTE salad and B. cereus in RTE tas kebab/salad samples showed insufficient cleaning/disinfection practices. As a result, hygiene practices and regular monitoring in the catering business are necessary for food safety.

Yogurt fortified with GABA-producing strain and Ganoderma lucidum industrial wasteOriginal Paper

Marina Jovanoviæ, Petar Vojvodiæ, Marija Petroviæ, Danka Radiæ, Dragana Mitiæ-Æulafiæ, Marija Kostiæ, Sonja Veljoviæ

Czech J. Food Sci., 2022, 40(6):456-464 | DOI: 10.17221/164/2022-CJFS

This study aimed to produce yogurt with Ganoderma lucidum residues and selected probiotic bacteria. To select the most potent GABA-producing strain (GABA - γ-aminobutyric acid), nine probiotic bacteria were subjected to the glutamate decarboxylase (GAD) activity assay. Limosilactobacillus reuteri DSM 17938 was selected and used in preparing fresh yogurts, with and without supplementation of Ganoderma residues obtained after water extraction [GW (Ganoderma waste) 2% (w/v)]. A decrease in pH during fermentation and the occurrence of syneresis were investigated. Lactic acid bacteria (LAB) viability and anti-Escherichia activity were estimated. Further, the cytotoxic effect of yogurt extracts on the human colon cancer cell line (HCT116) was surveyed. Besides functionality, the sensory attributes were evaluated. The pH values did not significantly change with the GW addition while increasing the LAB counts [up to 9.76 ± 0.11 log colony-forming units (CFU) mL-1] and the cytotoxic effect on HCT116 cells. Yogurt produced with selected bacteria and GW had the most valuable anti-coli effect against E. coli 0157: H7 and E. coli ATCC 35218 (American Type Culture Collection, Rockville, Maryland) (4.81 ± 0.62 and 5.64 ± 0.29 CFU mL-1, respectively). Although the added GW increased the yogurt functionality, it had a slightly negative effect on the taste and texture of the partially modified recipe. Yogurts fortified with GABA-producing strain and GW could potentially reduce relapse rates of depressive disorders.

Influence of the surface/volume ratio on the rheological properties of starch dispersionsOriginal Paper

Gerardo Lopez-Echevarria, Jorge Adalberto Huerta-Ruelas, Gonzalo Velazquez, Martin Jesús Nieto-Perez, Guadalupe Mendez-Montealvo

Czech J. Food Sci., 2023, 41(1):54-63 | DOI: 10.17221/155/2022-CJFS


This study aims to evaluate the influence of the surface/volume granule ratio of amaranth, corn, and potato starches on the rheological properties of pastes and gels obtained at 5 and 10% solids concentration through granulometry, scanning electron microscopy, rotational, and dynamic rheological measurements. The granule size distribution and the surface/volume ratio drove the rheological behaviour as a function of temperature and concentration. At a concentration of 10%, the consistency index of corn starch (CS) paste was 147.25 Pa·sn (n – flow behavior index), a higher value compared to pastes from potato starch (PS), 86.54 Pa·sn, and amaranth starch (AS), 44.48 Pa·sn. The lowest values of the loss angle tangent (Tan δ) in CS (0.052 and 0.035) at both solids concentrations suggested a better gel conformation. Noticeable changes in consistency index and storage modulus were observed in CS. A theoretical analysis of the surface/volume ratio change showed that CS reached a 2.2 value, much lower than the 4.5 and 5.8 values for PS and AS, respectively. These findings provide additional criteria for the food industry when choosing starches with suitable rheological behaviour as a function of surface/volume granule ratio and solids concentration.

Optimising consumer acceptability of Cauca specialty coffee through roasting profiles on acidity and body sensory attributesOriginal Paper

Diego Andrés Campo-Ceballos, Carlos Alberto Gaviria-López

Czech J. Food Sci., 2023, 41(1):64-72 | DOI: 10.17221/181/2022-CJFS

The roasting coffee process is the compilation of time-temperature-dependent physical and chemical transformations induced by heat. Through the study of the time-temperature curve, the correct definition of the degree of roasting of coffee is an area of active and non-trivial research, which intervenes in obtaining consistent roasting profiles reflected in the acceptability of the drink perceived by consumers. This paper used the methodology of response surfaces (RSM) with the central composite design (CCD). A consumer study was conducted with 104 individuals, each tasting 13 cups of specialty coffee from Cauca-Colombia. Predictive equations for acidity and body perception were obtained. The roasting profile points in charge, turning point, yellow, brown, first crack, and drop step were included. Mathematical models predict the acidity and body perceptions by integrating the roasting profile points characteristics of coffee. The Cauca coffee beans produced using the optimied conditions contribute to obtaining a roasting time/temperature of 468 s at 192 °C, respectively, with acidity (9/15) and body (5.5/15) in the (0–15) intensity consumer's perception scale.

Effect of buckwheat flour on microelements and proteins contents in gluten-free bread

Urszula Krupa-Kozak, Ma³gorzata Wronkowska, Maria Soral-¦mietana

Czech J. Food Sci., 2011, 29(2):103-108 | DOI: 10.17221/136/2010-CJFS

Coeliac disease is an autoimmune gluten-sensitive entheropathy. The only available treatment for it is the life-long adherence to a gluten-free diet although these products are often poor in proteins, minerals, and vitamins. The current study was designed to investigate the effect of buckwheat flour incorporation to a gluten-free experimental formulation on the size-related parameters, and microelements and proteins contents. Buckwheat flour affected positively the technological quality of bread, like bread specific volume index and loaf size. Increasing concentration of buckwheat flour (10-40%) in bread affected the proportional enrichment in proteins and microelements, especially in copper and manganese.

Potential of moringa (Moringa oleifera) leaf powder for functional food ingredients: A reviewReview

Lina Novi Ariani, Teti Estiasih, Wenny Bekti Sunarharum, Alfi Khatib

Czech J. Food Sci., 2023, 41(1):8-20 | DOI: 10.17221/221/2022-CJFS


One of the efforts to produce functional foods is using ingredients containing health-beneficial bioactive compounds. Another way to produce functional foods is fermentation generating bioactive compounds or fortification with the bioactive compound extract. An ingredient historically believed to have benefits on health is moringa (Moringa oleifera) leaf powder. Moringa leaf powder is a valuable source of functional ingredients, including protein, vitamins, minerals, and phytonutrients such as carotenoids, tocopherols, polyphenols, flavonoids, alkaloids, and tannins. However, moringa is a plant that is distributed in various tropical countries in the world. Its quality depends on geographical differences, cultivars, environmental conditions, seasons, genotypes, and varieties. This article reviews the bioactive compounds of moringa leaf powder and the characteristics of moringa leaf powder extract. The effect of moringa leaf powder fortification on food product characteristics is also discussed. Moringa leaf powder possesses many pharmacological properties, such as anticancer, anti-inflammatory, hepatoprotective, cardioprotective, and antioxidant ones. The bioactivity of leaf extract is extracting solvent dependent. Therefore, fortification results in nutritional improvement and increasing health benefits of food products. However, the adverse effect is found in sensory. Thus properties, thus the moringa leaf powder fortification level usually is less than 10%. Changes in the functional properties of foods due to moringa leaf powder fortification have been studied to a limited extent. A low level of fortification might not affect the properties of food products. Therefore, moringa leaf powder is potentially used as a functional food ingredient. Some studies reported the toxicological effects of moringa leaf powder and the use of this ingredient, should be below the harmful doses.

The use of modern fermentation techniques in the production of traditional wheat breadOriginal Paper

Pavel Skøivan, Marcela Sluková, Ivan ©vec, Helena Èí¾ková, Iveta Horsáková, Eli¹ka Rezková

Czech J. Food Sci., 2023, 41(3):173-181 | DOI: 10.17221/39/2023-CJFS

A traditional Czech bakery white bread product is commonly made with directly mixed dough with the addition of yeast. In order to be able to reduce the salt content of the final product without compromising its acceptability to consumers, the dough was prepared with the addition of pre-ferments and wheat sourdoughs. The aim was to deepen the flavour background of the product and thus have a positive effect on its sensory properties. Wheat sourdoughs were prepared and tested using starter cultures and matured under different conditions. The resulting products were tested both sensorially and by means of precise physical methods.

Ultra-high-pressure technology for preservation of fresh aquatic foods: A reviewReview

Jiakun Peng, Chune Liu, Kaikai Bai, Shaohua Xing, Feng Liu

Czech J. Food Sci., 2023, 41(5):313-322 | DOI: 10.17221/87/2023-CJFS


Aquatic foods such as fish, shrimp, and shellfish are important human nutrient sources. However, aquatic foods spoil quickly during processing and storage due to spoilage bacteria and endogenous enzymes. Ultra-high-pressure (UHP) technology, as an advanced non-thermal treatment method, is an effective preservation technique for aquatic foods. The mechanism of UHP technology is to destroy non-covalent bonds by UHP, which leads to the change of cell membrane permeability and the destruction of high-level structure of proteins, making apoptosis and enzyme inactivation. The technology can effectively sterilise and preserve food's colour, taste and nutritional value. The paper provides an introduction to the working principles, types, sources and equipment and describes the progress of the research and application of UHP technology in pascalisation, enzyme inactivation, parasite inactivation and quality modification of aquatic products. Potential limitations and prospects of the technology are also outlined. We hope to lay the theoretical groundwork for using this technique in aquatic product processing and provide guidance for its application in industrial production.

Development of a novel invA gene-based real-time PCR assay for the detection of Salmonella in foodOriginal Paper

Marko Dmitric, Dejan Vidanovic, Kazimir Matovic, Bojana Tesovic, Milanko Sekler, Ivan Vicic, Nedjeljko Karabasil

Czech J. Food Sci., 2023, 41(4):287-294 | DOI: 10.17221/114/2022-CJFS


In this study, the primers and the probe were designed, and a completely new real-time polymerase chain reaction (PCR) protocol for detecting the invA gene of Salmonella in food was optimised and validated in-house. The inclusivity test used 76 different Salmonella isolates with no false-negative results. The exclusivity was tested using 45 non-Salmonella microorganisms with no false-positive results. The method was also successfully applied while examining five different artificially contaminated food categories. The results were compared to the standard method (ISO 6579-1) and two previously validated real-time PCR methods. The developed assay is sensitive and specific for rapidly detecting Salmonella in food.

Common bean (Phaseolus vulgaris L.) seed germination improves the essential amino acid profile, flavonoid content and expansion indexShort Communication

Luis Díaz-Batalla, Karina Aguilar-Arteaga, Javier Castro-Rosas, Reyna Nallely Falfán-Cortés, Ricardo Omar Navarro-Cortez, Carlos Alberto Gómez-Aldapa

Czech J. Food Sci., 2023, 41(1):73-77 | DOI: 10.17221/5/2022-CJFS

Common bean (Phaseolus vulgaris L.) is one of the most important grain legume foods for the human diet. Common bean seed is gaining attention due to its content of secondary metabolites with positive effects on human health. The present work analysed the effect of common bean germination on the essential amino acid profile, active compound content, and expansion index after extrusion processing. The content of tryptophan (Trp) in raw common bean (RCB) and in germinated common bean (GCB) seeds was 6.1 and 7.9 mg·g–1 of protein, respectively. The limiting amino acids in RCB were sulphur amino acids and Trp, and in GCB only the sulphur amino acids were the limiting amino acids. The germination process in beans increases the levels of quercetin and kaempferol and allows the synthesis of daidzein and genistein, and significantly increases the expansion index after extrusion processing. The germination of common bean could be used as a strategy to improve nutritional, nutraceutical, and processing properties.


The effects of heat treatment on the quality of fat in flaxseeds and chia seedsOriginal Paper

Matej Brestenský, Soòa Nitrayová, Peter Patrá¹

Czech J. Food Sci., 2023, 41(1):21-28 | DOI: 10.17221/159/2022-CJFS


Flaxseeds (Linum usitatissimum L.) (FS) and chia seeds (Salvia hispanica L.) (ChS) contain fatty acids (FA) with beneficial health effect for the human body. Some people often use them as part of boiled or baked dishes. Therefore, the aim of this study was to observe the effect of FS and ChS heat treatments at 40 °C and 150 °C for 20 min on the content of fat, FA, atherogenicity index (AI) and thrombogenicity index (TI), and total antioxidant activity (TAA) in comparison with heat treatments at 20 °C. The content of fat in FS was higher in comparison with ChS (P < 0.05). Similarly, the content of alpha-linolenic acid, oleic acid, polyunsaturated FA, and monounsaturated FA was greater (P < 0.05) in FS when compared with ChS. However, n6 : n3 ratio [n6 – omega 6 polyunsaturated FA (PUFA), with first double bound on 6th carbon; n3 – omega 3 PUFA, with first double bound on 3rd carbon], AI and TI were lower (P < 0.05) in FS in comparison with ChS. The TAA in FS was 37% lower (P < 0.05) compared to ChS, moreover TAA in FS decreased (P < 0.05) at 150 °C in comparison with 20 °C and 40 °C. No effect of different heat treatments was observed on the content of FA or AI and TI in FS and ChS.

Investigate the mystery of Baijiu production region – Environmental factors for Luzhou (Sichuan, China)Review

Guo Qingyan, Tang Yurun, Zhao Fan, Liu Ying, Tian Lei, He Zongjun, Guan Tongwei

Czech J. Food Sci., 2023, 41(5):323-339 | DOI: 10.17221/72/2023-CJFS


With a long tradition of brewing history, Chinese strong-flavour Baijiu (SFB) developed prosperously in the southwest, especially in Luzhou, and has existed for more than 300 years building craftwork and brewing techniques. As a product of the distillation of fermented grains, its production involves many microbial communities. During this time, microbial communities within production have burgeoned and evolved throughout the development history, enhancing unique texture and flavour. Meanwhile, environmental factors are critical constituents in the production, which provide the optimal conditions for processing procedures and various microorganisms, including externally controlled macro-environment and micro-environment of fermentation. By studying the correlation with environmental factors from macro and micro perspectives, we illustrated the bond with environmental symbiotic and holistic patterns of the intrinsic microbial community and fermentation characteristics. This review is essential to study and control the whole ecological conditions of the Baijiu fermentation process, aiming to gain insight into the dynamics of the microorganisms and ensure a traditional fermentation environment for quality control.

Packaging types as influencing seed quality in some soybean [Glycine max (L.) Merr.] varieties during storage periodOriginal Paper

Ratna Wylis Arief, Robet Asnawi, Reny Debora Tambunan, Nila Wardani, Dewi Rumbaina Mustikawati, Made Jana Mejaya

Czech J. Food Sci., 2022, 40(3):229-239 | DOI: 10.17221/119/2021-CJFS

The post-harvest process at the storage stage is one of the most critical processes for maintaining soybean seed quality. The type of packaging and the type of material stored will affect its shelf life. One type of packaging has specific properties that are different from other types of packaging. Therefore, this study used several types of packaging materials and soybean varieties to determine changes in its quality during storage. The treatments were arranged in a 5 × 4 × 7 factorial experiment in a randomised block design (RBD) with three replications, consisting of totally 140 treatment combinations involving five different types of packaging materials. Water content, the weight of 100 grains, seedling dry weight, electrical conductivity (EC), and germination percentage were assessed monthly. The factorial analysis of variance (ANOVA) was used to compare water content, the weight of 100 grains, EC, germination, and seedling dry weight. A qualitative descriptive analysis method was employed for the temperature and relative humidity of the storage room. The results showed that Grobogan had the lowest germination percentage of 84.85% compared to the other varieties (86.97-90.82%). Plastic sack resulted in the most inferior seed quality (82.00% for plastic sack vs. 88.23-90.17% for the other containers). A more extended storage period of soybean seeds caused a decrease in soybean quality for all varieties and packaging materials. Up to 6 months of storage at room temperature, the quality of soybean seeds remained high, with the lowest germination of 80%.

Correlation between acrylamide content and colour in some baked productsOriginal Paper

Zana Mohammed Abdulazeez, Abdel Moniem Ibrahim Mustafa, Fehmi Yazici

Czech J. Food Sci., 2023, 41(2):137-143 | DOI: 10.17221/244/2022-CJFS

The objective of this study was to quantify the concentration of acrylamide in biscuits, bread, and cake obtained from industrial and local bakeries, classified based on their colour intensity as light, medium, or dark. The analysis was performed using gas chromatography-mass spectrometry (GC-MS). Sugar, moisture, and asparagine analyses were also carried out simultaneously. The results demonstrated that the acrylamide content in biscuits, bread, and cakes varied according to the colour (light 109.9 ± 7.95, 214.7 ± 27.40, and 128.6 ± 7.05; medium 176.3 ± 15.16, 387.0 ± 87.71, and 804.3 ± 17.16; and dark 407.6 ± 105.13, 555.8 ± 16.20, and 1 015.0 ± 83.68 µg·kg–1, respectively). Statistically, significant differences were observed between acrylamide content and product colour density (P < 0.05). It can be concluded that the acrylamide content increases as the product colour intensity rises due to the increased baking temperature at which the reaction between reducing sugars and asparagine takes place, resulting in the formation of acrylamide. The results suggest that selecting commercial bakery products based on colour may be beneficial for reducing the daily intake of acrylamide by consumers. Therefore, it is recommended to avoid dark-coloured bakery products.

Characteristics of cases with foodborne diarrheagenic Escherichia coli infection in Huzhou, ChinaOriginal Paper

Deshun Xu, Lei Ji, Wei Yan, Yuehua Shen

Czech J. Food Sci., 2023, 41(6):446-454 | DOI: 10.17221/151/2023-CJFS


Diarrheagenic Escherichia coli (DEC) is a common pathogen around the world that can cause disease with symptoms of diarrhoea. We collected all clinical DEC isolates from diarrhoea samples in three sentinel hospitals for active surveillance of foodborne diseases in Huzhou, China, between 2020 and 2022. The isolates were characterised according to demographic characteristics, time distribution, distribution of suspected culprit foods, antimicrobial results of susceptibility testing, analysis of virulence genes, and pulsed-field gel electrophoresis (PFGE) typing. The positive detection rate was 7.28%, the highest for enteroaggregative E. coli (EAEC) strains, followed by enterotoxic E. coli (ETEC) strains. The predominant virulence genes were astA/pic in EAEC (57.25%) and estIa/estIb in ETEC (17.94%) strains. The proportion of cases was relatively high in children aged 6 years old (15.27%), and the peak of incidence was between June and September. The rates of drug resistance in DEC were high in Huzhou, and the spectrum of drug resistance was wide. The highest rate of drug resistance was for AMP (63.51%), and multiple drug resistance was common. The household was the leading site of DEC infection, and meat and meat products were the main suspected culprit foods (18.15%). EAEC strains showed 52.4–100.00% sequence identity, and ETEC strains showed 52.2–100.00% sequence identity. All cases of DEC infection in Huzhou were sporadic between 2020 and 2022. Strengthening continuous surveillance will be useful in the risk assessment of foodborne diseases caused by DEC.

Analysis of chemical and sensory parameters in different kinds of escolar (Lepidocybium flavobrunneum) productsFood Analysis, Food Quality and Nutrition

Hana BUCHTOVÁ, Ðani ÐORÐEVIÆ, Stanislav KOÈÁREK, Petr CHOMÁT

Czech J. Food Sci., 2015, 33(4):346-353 | DOI: 10.17221/435/2014-CJFS

The chemical composition (nutritional and freshness parameters) and sensory characteristics were evaluated of escolar (Lepidocybium flavobrunneum) defrosted raw fillets and steaks that were marinated differently (pepper, onion, chilly, herbs, knusper, and hot) and packaged in a manner suitable for microwave heating (Darfresh® Simple Steps®). The study was carried out by using 8 skinless fillets of Lepidocybium flavobrunneum. The selected 18 parameters, i.e. dry matter/moisture, crude protein, net protein, collagen, net muscle protein, lipid, ash, saccharide, energy value, pH, water activity, salt content, total volatile basic nitrogen, trimethylamine, free fatty acids, peroxide value, and thiobarbituric acid assay were evaluated. The results indicate that the sample of Chilly marinated steaks was evaluated as the best one (90.29 ± 9.82), however, the samples of Herbs (89.6 ± 13.89) and Knusper (88.64 ± 15.59) marinated steaks also received more than 85 points for the overall impression. Control sample received the smallest number of points (71.7 ± 26.54) for the overall impression.

Influence of co-encapsulation of Bifidobacterium animalis subsp. lactis Bb12 with inulin and ascorbic acid on its viabilityOriginal Paper

Monika Kumherová, Kristina Veselá, Kateøina Joke¹ová, Iveta Klojdová, ©árka Horáèková

Czech J. Food Sci., 2020, 38(1):57-62 | DOI: 10.17221/292/2019-CJFS

Eight types of capsules containing Bifidobacterium animalis subsp. lactis Bb12 with addition of inulin and/or ascorbic acid were prepared by emulsion method with milk protein matrix or by extrusion method with alginate matrix. The size of protein and alginate capsules containing only Bb12 was 204 ± 18 µm and 1.7 ± 0.1 mm, respectively. Addition of both inulin (1% w/w) and ascorbic acid (0.5% w/w) increased the size of alginate capsules. Both methods of encapsulation prevented efficiently the manifestation of Bb12 cell metabolic activity. All types of encapsulation provided higher resistance of Bb12 cells to the conditions of a model gastrointestinal tract (GIT) compared to free cells. The influence of co-encapsulation with inulin (1% w/w) and ascorbic acid (0.5% w/w) on viability in model GIT was not demonstrable in alginate capsules but it was significant in protein capsules. The most efficient was co-encapsulation in a protein matrix with 1% w/w inulin and 0.5% w/w ascorbic acid.

Grapevine extracts and their effect on selected gut-associated microbiota: In vitro studyOriginal Paper

Michaela Rollová, Lucia Gharwalová, Ale¹ Krmela, Vìra Schulzová, Jana Haj¹lová, Petr Jaro¹, Irena Kolouchová, Olga Ma»átková

Czech J. Food Sci., 2020, 38(3):137-143 | DOI: 10.17221/308/2019-CJFS

The biological activity of polyphenol substances contained in food supplements prepared from Vitis vinifera can affect the microorganisms present in the digestive tract in terms of their representation and activity of the individual species. This study deals with resveratrol and two polyphenol-rich extracts (extract from V. vinifera canes and the commercial product Regrapex-R-forte) and their effect on selected gut microbiota (Bifidobacterium animalis subsp. lactis Bb-12, Lactobacillus acidophilus LA-5, Lactobacillus casei Lafti L-26, Citrobacter freundii DBM 3127, Escherichia coli DBM 3125). The effect of the studied agents on planktonic and biofilm growth of the microorganisms was determined as minimum inhibitory concentration (MIC80) and minimum biofilm inhibitory concentration (MBIC80), respectively. The extracts induced metabolic activity as well as total biofilm biomass production in probiotic strain L. acidophilus LA-5 while successfully inhibiting the growth of opportunistic pathogenic microorganisms C. freundii DBM 3127 and E. coli DBM 3125.

Attitude of assessors in the Czech Republic to the consumption of house cricket Acheta domestica L. - A preliminary studyShort Communication

Lenka Kouøimská, Veronika Kotrbová, Martin Kulma, Anna Adámková, Jiøí Mlèek, Monika Sabolová, Dana Homolková

Czech J. Food Sci., 2020, 38(1):72-76 | DOI: 10.17221/49/2019-CJFS

Sensory acceptability of the consumption of whole baked house crickets by assessors in the Czech Republic was investigated. The main aim was to observe attitudes to eating edible insects before and after their tasting and to assess the extent of the effect of prejudices. Hedonic evaluation of the overall acceptability of edible insects was carried out under laboratory conditions by trained assessors. Of the 98 panellists, 68 were willing to evaluate the sample visually and then by tasting. They showed statistically significant differences (P < 0.0001) in overall pleasantness before tasting (40 ± 22%) and after tasting (61 ± 17%). No statistically significant differences between male and female assessors were observed, either before or after tasting. Women and younger assessors were slightly more open to entomophagy, but there were no statistically significant differences between males and females or between the two age categories (18-25 and 26-45 years of age) in the results. The preferred methods of culinary preparation of edible insects that the respondents would choose were baking, roasting and frying.

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