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Results 121 to 150 of 583:

Free amino acids, fatty acids and phenolic compounds in Tartary buckwheat of different hull colourFood Analysis, Food Quality and Nutrition

Lian-Xin Peng, Liang Zou, Mao-Ling Tan, Yuan-Yuan Deng, Juan Yan, Zhu-Yun Yan, Gang Zhao

Czech J. Food Sci., 2017, 35(3):214-222 | DOI: 10.17221/185/2016-CJFS

In this paper, free amino acids, fatty acids, and phenolic compounds in buckwheat of different hull colour were quantified by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), gas chromatography-mass spectrometry (GC-MS), and high performance liquid chromatography-ultraviolet detector (HPLC-UV), respectively. A total of 20 free amino acids, 8 fatty acids, and 6 phenolic compounds were detected in Tartary buckwheat flour and bran. The data on concentrations were subjected to common chemometric analyses, including principal component analysis (PCA) and hierarchical cluster analysis (HCA), to gain better understanding of the differences between the tested samples. Results indicated that most of the free amino acids, fatty acids, and phenolic compounds were higher in bran than in flour, and there is no significant difference in respect to the hull colour. Our results may be helpful for quality control in Tartary buckwheat and its products in the future.

Nine-year statistics of Czech honey carbohydrate profiles in the Czech RepublicOriginal Paper

Helena Èí¾ková, Dalibor Titìra, Pavel Hrabec, Matej Pospiech

Czech J. Food Sci., 2022, 40(2):85-92 | DOI: 10.17221/213/2021-CJFS

Honey is composed mainly of carbohydrates which are represented by mono-, di-, tri-, tetra-, pentasaccharides, and oligosaccharides. The content and proportions of individual carbohydrates reveal information about the origin and technological properties of honey. A total of 5 987 samples of natural honeys originating from the Czech Republic and harvested during a period of nine consecutive years were analysed to research their carbohydrate content, sum of fructose and glucose (Fru + Glc), fructose and glucose ratio (Fru/Glc), and electrical conductivity (Ec). Monosaccharides, melezitose (Mel), and Ec varied according to the source of nectar or honeydew. Sucrose (Suc) content was low 0.87 ± 1.26 g (100 g)-1 and did not exceed 15 g (100 g)-1.

Water activity of Czech dry-cured meat products: Influence of sampling point and sample preparation methodOriginal Paper

Filip Beòo*, Jan Kostlán, Jan Pivoòka, Václav Pohùnek, Rudolf ©evèík

Czech J. Food Sci., 2023, 41(5):340-347 | DOI: 10.17221/99/2023-CJFS


Water activity (aw) is a key factor influencing dry-cured meat products' safety. However, the standards for determining aw do not specify how the laboratory sample for self-analysis should be prepared and adjusted for determination in this type of food. This work aimed to verify whether the place of sampling and method of sample preparation of dry-cured meat products can influence the measured value of aw. For this purpose, samples of dry-cured heat-treated and fermented meat products were purchased from the local market. Samples before analysis were taken from the edges and centre of the meat products, and preparation consisted of: i) homogenisation; ii) dicing (4 × 4 × 4 mm); iii) slicing. The results of this work indicate that aw is significantly affected by both the part of the product from which the sample is taken and the method of preparation of the sample itself (P < 0.05). The highest measured values of aw were determined in samples prepared by slicing, and the lowest values were determined in homogenised samples. The place of sampling significantly affects the aw, especially for dry-cured heat-treated products.


Chemical composition, antimicrobial activities, and molecular docking studies of Turkish propolis ethanol extractOriginal Paper

Gokben Ozbey, Mustafa Necati Muz, Elif Seren Tanriverdi, Sultan Erkan, Niyazi Bulut, Baris Otlu, Franti¹ek Zigo

Czech J. Food Sci., 2023, 41(2):144-154 | DOI: 10.17221/100/2022-CJFS


The purpose of the present study was to investigate the antimicrobial effect of propolis ethanol extract collected from the Tarsus district of Mersin province, Kilis province, Yayladagi district of Hatay province in southern Türkiye and Sarkoy district of Tekirdag province of northwestern Türkiye against Escherichia coli (ATCC 25922), Helicobacter pylori (ATCC 43504), Pseudomonas aeruginosa (ATCC 27853), and Staphylococcus aureus (ATCC 29213). Their chemical constituents were detected via liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). They were used in a molecular docking approach to search the interactions between the propolis compounds. A total of 24 phenolic compounds were detected in all samples. 3–4 dimethoxycinnamic acid, caffeic acid and genistein were indicated to be the predominant phenolic compounds in propolis extracts by LC-MS/MS, while rutin was found in the lowest concentration. Phenolic compounds were detected in a high concentration of the propolis samples collected from the Tarsus district of Mersin province. The broth microdilution method determined minimum inhibition concentration (MIC) values. MIC values ranged from 0.02 to 14 mg·mL–1. E. coli and S. aureus examined were as susceptible to the propolis extracts except for Mersin and Tekirdag propolis samples. The propolis sample collected from the Tarsus district of Mersin province presented the highest antibacterial activity on P. aeruginosa with MIC values of 1 mg·mL–1. Active substances in propolis were docked to the relevant target proteins (5LMM, 4NX9, 5YHG, and 5FXT) representing E. coli (ATCC 25922), H. pylori (ATCC 43504), P. aeruginosa (ATCC 27853), and S. aureus (ATCC 29213), and with the help of molecular simulation. With this study, we indicated that the ethanol extract of propolis had a stronger antibacterial activity on S. aureus isolates than that of E. coli, H. pylori, and P. aeruginosa. Although each component of propolis contributed to the antibacterial activity, the contribution of the vitexin component to the antibacterial activity was found to be quite significant.

Extraction and enzymatic modification of dietary fibre from purple aubergineOriginal Paper

Suwalee Fong-in, Kamonlak Wicharaew, Pattaramon Phalapan, Trakul Prommajak

Czech J. Food Sci., 2023, 41(4):304-312 | DOI: 10.17221/84/2023-CJFS

This research scrutinised the opportunity of upcycling waste from the food industry by extracting dietary fibre from purple aubergine. One of the challenges addressed was enzymatic browning, which negatively influenced the quality of the fibre extracted from fresh aubergine. Various pre-treatment procedures were assessed, including using citric acid, sulphite immersion, peeling and thermal processing, to determine their effects on extraction yield, colour, and the functionality of the resultant dietary fibre. Findings indicated that a pre-treatment method involving aubergine peeling, sulphite solution immersion, and subsequent steaming before extraction produced optimal results, enhancing both whiteness index and water-holding capacity. Experiments were conducted with traditional enzymes supplemented with cellulase, xylanase, and lipase for enzymatic extraction. The addition of lipase notably elevated the extraction yield and water-holding capacity, albeit with an undesired darkening effect on the dietary fibre. In contrast, the application of xylanase emerged as the most effective treatment, delivering the highest overall quality for the derived dietary fibre.

Nutritional evaluation of the full-day dietOriginal Paper

Barbora Pohoøelá, Andrea Poláchová, Markéta Rù¾ièková, Marek Dole¾al, Jana Pulkrabová, Jan Pánek

Czech J. Food Sci., 2022, 40(2):118-129 | DOI: 10.17221/273/2021-CJFS

Nutrition plays an important role in human life. So far, there have been discussions focusing on the nutritional value of individual foods, separate dishes, or daily meals. However, they have not taken into account the composition of the diet in the longer term. The aim of this work was to evaluate a full-day diet from a currently renowned company that is producing box diets on the Czech market against a full-day diet of twenty randomly selected students. The results showed that the box diet met the required amount of protein, fat, vitamin E, cholesterol, and also the optimal intake of n-6 and n-3 fatty acids. The amount of saturated fatty acids (SFA) was only slightly increased. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) content averaged 38 mg day-1, which did not meet the current requirements. The students' full-day diet was variable, the individual differences were large. Protein intake could be assessed as sufficient in most cases. The total fat intake ranged from 21 g day-1 to 126 g day-1. Seven out of twenty samples would satisfy the recommendation for SFA. The content of the essential acids EPA and DHA was below the detection limit with the exception of one sample (containing herring fillets).

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.

Biodiversity of Vitis vinifera endophytes in conventional and biodynamic vineyardOriginal Paper

Maria Vrublevskaya, Thi Tra My Nguyenová, Lucie Drábová, Petra Lovecká, Blanka Vrchotová, Olga Ma»átková, Markéta Kuli¹ová, Irena Jaro¹ová Kolouchová

Czech J. Food Sci., 2023, 41(1):44-53 | DOI: 10.17221/200/2022-CJFS


Plants are permanently exposed to biotic and abiotic stress and have therefore developed intricate resistance mechanisms, consequently. These include the presence of microbial endophytes, which can promote plant growth and ensure better resilience against unfavourable conditions. These microorganisms colonising plant tissues can directly affect plant growth by producing phytohormones, antioxidants, 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, or indirectly by the production of siderophores and antifungal agents. To the best of our knowledge, this is the first study devoted to assessing bacterial endophyte diversity and their plant growth-promoting properties in two utterly distinct vineyards in view of agricultural management (conventional, biodynamic) in the Czech Republic. With these different agricultural approaches, we hypothesised different numerical representations of bacterial endophytes acquired from vine shoots and leaves, which was not proved (P = 0.743, F = 0.129). A total of 470 distinct bacterial endophytes were isolated from the Vitis vinifera plants from the conventional and biodynamic vineyard and from which over 80% were identified by the matrix-assisted laser desorption-time-of-flight mass spectrometry (MALDI-TOF MS). In both vineyards, the dominant bacterial genus was Bacillus, followed by Pantoea, Pseudomonas and Staphylococcus. Plant-promoting endophyte properties varied with respect to the season and type of vineyard. The ability to produce indole-3-acetic acid (IAA) and ACC deaminase was higher in the biodynamic vineyard, in comparison with antioxidant activity, which was found in a higher proportion in isolates from the conventional vineyard.

Impact of lard-based diacylglycerols on the quality and sensory characteristics of emulsion-type sausageOriginal Paper

Xiaoqin Diao, Weiting Sun, Dengyong Liu*, Haining Guan*, Ruixin Jia, Ying Wang

Czech J. Food Sci., 2023, 41(3):196-203 | DOI: 10.17221/111/2022-CJFS


The objective of this study was to evaluate the effects of fat levels (200 g·kg–1 meat and 500 g·kg–1 meat) and types [lard, glycerolised lard (GL), and purified glycerolised lard (PGL)] on the quality and sensory characteristics of emulsion-type sausages. As observed, at the same type of fat, the low-fat sausage (200 g·kg–1 meat) had a significantly higher L*-value (lightness) and lower cooking loss and total expressible fluid (P < 0.05) than the high-fat sausage (500 g·kg–1 meat) and exhibited a denser and more homogeneous microstructure. Additionally, T23 (relaxation time) of the low-fat sausage shifted toward a slower relaxation time, and higher A23 (peak area) was found, which suggested the water mobility was restricted. However, at the same fat content, the low-GL and low-PGL sausages showed better textural properties and superior overall acceptability from sensory evaluation compared with the low-lard sausage (P < 0.05). Still, they have no significant differences (P > 0.05). Therefore, lard-based diacylglycerol could be effectively applied as a fat replacer in emulsion-type sausages with low-fat contents to produce healthier meat products.

Improving the nutritional quality of cereals and legumes by germinationOriginal Paper

Ayºe Seda ªenlik, Derya Alkan*

Czech J. Food Sci., 2023, 41(5):348-357 | DOI: 10.17221/44/2023-CJFS

Cereal and legume grains are germinated to improve their nutritional and sensory qualities. This study investigated the effect of germination on the physicochemical properties of some grains and legumes grown in Türkiye. At the end of the germination for 48 h and 96 h at 24 ± 1 °C, carbohydrate, protein, lipid, dietary fibre, dry matter, ash, total phenolic content, antioxidant capacity and colour analyses of the germinated grains were determined. The results indicated that the germination process increased the phenolic content of all samples. The legume seeds' 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity significantly increased with germination. The germination process significantly decreased the total carbohydrate contents of the samples. A statistically significant decrease was found for the protein content of barley and corn, especially by 48 h of germination. The lipid content of cereal grains decreased as germination progressed. It might be recommended to improve the functional properties of cereals and legumes by germination and their use in the food industry.

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.

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.

Effects of the addition of gluten with different disulfide bonds and sulfhydryl concentrations on Chinese white noodle qualityFood Technology and Economy, Engineering and Physical Properties

Cuicui LI, Qiyu LU, Zipeng LIU, Huili YAN

Czech J. Food Sci., 2018, 36(3):246-254 | DOI: 10.17221/326/2017-CJFS

The disulfide bonds and sulfhydryl in gluten were evaluated to investigate the effects of structural characteristics on the quality of white noodles. The free sulfhydryl concentration increased significantly, but disulphide bonds decreased initially, and then became stable with increasing sodium sulfite concentration. With a decrease in disulfide bond concentration from 56.78 μmol/g to 20.01 μmol/g in gluten added to noodles, microstructural graphs verified that the cross-section and surface of noodles became rougher and looser with more holes generated; optimal cooking time decreased from 4.4 min to 3.3 min for fresh noodles and from 10.11 min to 9.19 min for dried samples; water absorption and cooking loss increased from 159% to 203% and from 5.26% to 9.06%, respectively. A decreasing trend and marked differences were observed for hardness, springiness, chewiness as well as resilience of fresh and cooked noodles, but the cohesiveness of fresh noodles exhibited no significant changes (P < 0.05).

High pressure processing for the production of vegetable baby puree with enhanced nutritional, microbial, and sensory qualitiesOriginal Paper

Farah Javed, Hafiz Muhammad Shahbaz, Waqas Ahmed, Habib ur Rehman

Czech J. Food Sci., 2023, 41(4):263-270 | DOI: 10.17221/2/2023-CJFS


High-pressure processing (HPP) was used as a post-processing treatment for vegetable puree. Microbiological, physicochemical, nutritional, and sensory analyses of puree were investigated at room temperature. HPP (600 MPa, 5 min) was compared with thermal treatment (117 °C, 30 min) and fresh samples. Treatments did not change pH or total soluble solids. For both methods treated samples exhibited a lower microbial count (< 1.0 log CFU·g–1) over storage, compared with fresh puree. During storage, other parameters, including total phenolic contents and antioxidants also demonstrated similar or better performance than controls (P < 0.05). Overall, HPP-treated puree received a higher sensory evaluation score. Thus, HPP can be used as an alternative processing technology to improve nutritional quality and microbial safety.

Comparison of physicochemical properties, phenolic profiles and antioxidant capacity of hawthorn berries stored at different temperatures and timeOriginal Paper

Xueyan Wei, Yanjing Yin, Kang Xu, Tao Wang, Chuanhe Zhu, Wen Liu, Mengmeng Guo

Czech J. Food Sci., 2023, 41(6):419-427 | DOI: 10.17221/112/2023-CJFS

This research investigated the effect of different storage temperatures on the compositional changes, physicochemical characteristics, and functional properties of hawthorn berries. Storage at 25 °C resulted in the gradual decrease of the moisture, hardness, sugar, titratable acid, and colour of hawthorn berries. These changes decreased with decreasing storage temperature, and the minimal changes happened at frozen storage (–18 °C). Similarly, the decreasing rate of ascorbic acid, extractable polyphenol (EPP), and flavonoids during storage also decreased with reducing storage temperature (25 °C > 4 °C > –18 °C). Hydrolysable polyphenol (HPP) was relatively stable during the hawthorn storage, and non-extractable proanthocyanidins (NEPA) increased with decreasing temperature. Ferric reducing antioxidant power (FRAP) of EPP and HPP decreased at 25 °C, while polyphenolic oxidase (PPO) and peroxidase (POD) activities decreased. Decreasing the storage temperature can improve the stability of the nutritional properties, antioxidant capacity, and enzyme activity of hawthorn. The specific storage temperature depends on the final processing conditions and the purposes of the hawthorn berries.

Comparative study of physicochemical and hedonic response of ginger rhizome and leaves enriched pattiesOriginal Paper

Saira Tanweer, Muhammad Farhan Jahangir Chughtai, Saadia Zainab, Tariq Mehmood, Adnan Khaliq, Syed Junaid-Ur-Rahman, Rabia Iqbal, Atif Liaqat, Samreen Ahsan, Zulfiqar Ahmad, Aamir Shehzad

Czech J. Food Sci., 2021, 39(5):402-409 | DOI: 10.17221/261/2020-CJFS

The present investigation was an attempt to compare the phytoceutic potential of ginger rhizome and ginger leaves of the Suravi variety. For this purpose, both rhizome and leaves were dried and used for the preparation of patties. After that, patties were assessed for colour tonality, texture, total phenolic content and hedonic response such as colour, taste, flavour, texture and overall acceptability. The results depicted that L* and b* values changed significantly during the storage interval; however, b* value was also affected by treatments whilst L* and a* values did not impart any momentous effect. For texture, the highest value was observed for patties with ginger rhizome powder (0.067 ± 0.0032 N) followed by patties with ginger leaf powder (0.060 ± 0.0029 N) and then control patties (0.057 ± 0.0026 N). For total phenolic content (TPC), maximum phenolic contents were observed as 84.80 ± 3.31 mg GAE 100 g-1 in treatment T2 followed by 75.68 ± 2.95 mg GAE 100 g-1 in T1 and 61.70 ± 2.41 mg GAE 100 g-1 in T0. For hedonic response, all the parameters changed significantly during the storage interval; however, flavour, taste and overall acceptability changed momentously with treatments. The findings of the current investigation demonstrated that ginger leaves have a higher antioxidant potential as compared to the ginger rhizome and control patties, and they should be incorporated into food products.

Optimisation of experimental variables for extracellular amylase production by Bacillus cereus AS2Original Paper

Aneela Rehman, Asma Saeed, Wajeeha Asad, Ibrar Khan, Mujaddadur Rehman, Azam Hayat, Tawaf Ali Shah, Turki Mohammed Dawoud, Mohammed Bourhia

Czech J. Food Sci., 2024, 42(4):225-234 | DOI: 10.17221/193/2023-CJFS


Amylases are one of the biotechnologically important enzymes that have multiple applications in the food, pharmaceutical, cosmetics, textile, detergent, paper and pulp, bioremediation and nano-biotechnology industries. Amylases can be isolated from animals, plants and microbial regions, but nowadays enzymes from prokaryotic species have gained more importance. Among the microbes, amylases from Bacillus cereus have gained considerable demand in various industrial sectors. Growing industrial demand for enzymes compels the availability of enzymes in large quantities that can only be achieved by employing efficient fermentation techniques. Therefore, the current study is aimed at the statistical optimisation of the production conditions for extracellular amylase production from Bacillus strain AS2. In a recent study, the optimum amylase producing AS2 strain was identified on a molecular level, and it was found that it has close relation with the already reported strains of Bacillus cereus. The further enzyme production was optimised by using a statistical optimisation tool. A full-factorial central composite design (CCD) consisting of 53 experiments was designed using six significant variables (incubation period, pH, temperature, carbon and nitrogen source and metal ion). The analysis revealed that the optimal media concentrations were 54.34 g·L–1 starch, 0.63 g·L–1 CaCl2, 1 g·L–1 glycine, pH 7.0, 76 h, and 40 °C, respectively. A 1.23-fold increase in the enzyme yield (1 050 IU·mL–1·min–1) was noticed as compared to the original production level. The statistical optimisation approach gives the exact variables that influence the enzyme production and, hence, offers the best way to optimise the bioprocess. The optimised enzyme can be used in industries for various purposes such as de-sizing, de-inking, hydrolysing starch residues, etc.


Formation of sensory active substances during ripening of Dutch-type cheese with reduced salt contentOriginal Paper

Irena Nìmeèková, ©árka Tre¹lová, Helena Èí¾ková, Tereza Rambousková, Jan Forejt, Zdenìk ©vandrlík, Vojtìch Kru¾ík, Dana Gabrovská

Czech J. Food Sci., 2023, 41(2):103-110 | DOI: 10.17221/239/2022-CJFS

The reduction of NaCl content in cheeses is nutritionally desirable but quite challenging due to NaCl's key role during cheese production and ripening. We focused on reformulated Dutch-type cheeses ripened for 120 days and their microbiological and sensory characteristics, including of determining organic acids (electrophoresis) and volatile substances (SPME-GC-MS analysis). Experimental batches contained 0.64, 0.90, and 1.19% NaCl or 0.77% NaCl together with 0.33% KCl. The influence of salts on lactose and citrate metabolism (the formation of lactic, acetic, and formic acid, ethanol, diacetyl, acetoin and 2,3-butanediol), proteolysis (the formation of glutamic acid), lipolysis and β-oxidation of fatty acids (the formation of 2-butanone, 2-butanol, hexanal, hexanoic and octanoic acid) was undetected. Contrarily, brining conditions affected the contamination of cheese surfaces with yeasts and halotolerant microorganisms and cheese consistency. While a typical consistency was formed only in the cheeses with 1.19% NaCl acceptable saltiness was declared in the cheeses with the content of salts 0.90% or higher. The partial replacement of NaCl with KCl caused metallic off-taste in the cheeses that ripened longer than Consistent acceptance seems to be the most limiting factor for the tested reformulation appears.

Utilisation of chicken eggshell nanopowder on physicochemical quality, microstructure, and amino acid profile of beef pattiesOriginal Paper

Herly Evanuarini, Agus Susilo, Uun Yanuhar, Adelya Desi Kurniawati

Czech J. Food Sci., 2023, 41(6):428-435 | DOI: 10.17221/156/2023-CJFS

Chicken eggshells are a source of calcium and protein that can be added to restructured meat products, including patties. This study aimed to improve the chemical quality of beef patties with the addition of chicken eggshell nanopowder, including pH, protein content, ash content, fat content, antioxidant activity, calcium, microstructural quality, and identification of amino acid profiles. The method used in this study was a laboratory experiment arranged in a completely randomised design with five treatments: without the addition of chicken eggshell nanopowder as a control, the addition of chicken eggshell nanopowder 0.1, 0.3, 0.5, and 0.7% (w/w) with five replications. Data were analysed using the analysis of variance. It was followed by Duncan's multi-range test when the differences were significant or very significant. The research results show that the addition of chicken eggshell nanopowder to beef patties had a very significant effect (P < 0.01%) on pH, protein content, ash content, fat content, antioxidant activity, calcium, microstructural quality through scanning electron microscopy, and several amino acids. The addition of 0.7% chicken eggshell nanopowder could improve the chemical quality of the beef patties. The patty matrix was uniform and compact, and the air voids were getting tighter with the addition of chicken eggshell nanopowder, which was increasing based on scanning electron microscopy observations. Moreover, beef patties had various types of amino acids to achieve the best treatment.

The effect of different cooking methods on the antioxidant activity of wild Swiss chard (Beta vulgaris L. var. cicla)Original Paper

Yagmur Demirel Ozbek*, Ozlem Saral

Czech J. Food Sci., 2023, 41(5):375-381 | DOI: 10.17221/114/2023-CJFS


This study aimed to investigate the effects of different cooking methods (boiling for 5 min and 8 min, microwave cooking for 3.5 min and 6.5 min, and stir-fry for 5 min and 10 min) on wild chard's antioxidant activity and total phenolic content. It was determined that the total phenolic content [1 552.00 ± 299.82 mg GAE·(100 g)–1, GAE – gallic acid equivalents] increased in 3.5 min in the microwave [2 611.33 ± 311.76 mg GAE·(100 g)–1] and 5 min in stir-frying [2 434.33 ± 197.75 mg GAE·(100 g)–1] compared to the raw chard samples (P < 0.05). Two different antioxidant activity determination methods [2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and ferric reducing antioxidant power (FRAP)] were used in the study. In both methods, it was determined that antioxidant activity decreased in the 10-min application of stir-frying. In contrast, the antioxidant activity increased by applying 3.5 min and 6.5 min in the microwave (P < 0.05). As a result, it was found that the antioxidant activity and total phenol content of wild chard changed when the cooking method and time were changed.

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.


Fermentation of pineapple juice with Lactiplantibacillus plantarum subsp. plantarum Dad-13: Sensory and microbiological characteristicsOriginal Paper

Fariz Nurmita Aziz, Tyas Utami, Dian Anggraini Suroto, Rini Yanti, Endang Sutriswati Rahayu

Czech J. Food Sci., 2023, 41(3):221-229 | DOI: 10.17221/243/2022-CJFS


Among the varieties of pineapples, honey pineapple is suitable to be processed as a probiotic beverage. The study aimed to evaluate the honey pineapple juice as a growth medium for Lactiplantibacillus plantarum subsp. plantarum Dad-13 probiotic strain. The pineapple juice was fermented by adding a starter culture of L. plantarum Dad-13. The fermentation time (0, 4, 8, 12, 16, 20, and 24 h) was used as a variable. The number of L. plantarum Dad-13 cells increased significantly after fermentation (P < 0.05). In acidic pineapple juice L. plantarum Dad-13 can still grow more than 2 log cycles. After 16 h, the results showed the best characteristics with cell count (8.86 log CFU·mL–1), pH (3.52), and titratable acidity (0.59%). To balance the sour taste, the 8% sucrose addition was the most preferred by the panellists (n = 67), with a 5.74 (slightly like) overall acceptance score. After 42 days, there was no significant decrease in cell viability. The number of cells on day 42 was 8.81 log CFU·mL–1 with significant changes in pH and titratable acidity. The study showed that honey pineapple juice is a suitable growth medium for Lplantarum Dad-13.

Evaluation of protein quality of wheat-rye flour blends by use of two small-scale analytical methodsOriginal Paper

Ivan ©vec, Petra Smrèková

Czech J. Food Sci., 2024, 42(2):118-126 | DOI: 10.17221/187/2023-CJFS


The technological quality of the protein fraction of wheat white flour (WW) was determined by the lactic acid Solvent Retention Capacity and by the Gluten Performance Index (LA-SRC and GPI; AACC method 56-11.01). Parallelly, Perten's standard Gluten Index test (GI; AACC method 38-12.02) was performed with that wheat control. Consequently, the same methods were applied to 9 bi-composite blends mixed at ratios of 90 : 10, 80 : 20, 70 : 30, 60 : 40, 50 : 50, …, and 10 : 90 as WW replacement with one of the rye bread flours (RB), and the RB control itself. Unlike successful measurements in the case of the LA-SRC and GPI, washing gluten from the first 90 WW : 10 RB blend led to the clogging of the Glutomatic sieve, likely due to the interaction of wheat gluten with rye arabinoxylans. The discrepancy induced the development of a modification of the standard GI procedure; clogging was avoided by precipitating flour and centrifuging the swollen solid from suspension, similarly like in the SRC method. The settled residue transported to a standard sieve cassette was secondly centrifuged in the original apparatus Perten CF2015. The weighing of the overflow and underflow of the sieve and the calculation of the results were performed according to the original GI method. For the WW control, the standard GI value was 90% and the modified Gluten Index value (GImodif) was 82%. As expected for WW-RB counterparts, the higher the portion of rye in the bi-composite blend, the lower the value of the GImodif. For the 50 WW : 50 RB blend and the RB itself, the GImodif values were 47% and 18% (the GPI values 0.66, 0.45, and 0.39, respectively). On the contrary, the LA-SRC demonstrated a convex course (118, 104, and 123%, respectively). In the plane of the principal components (PC), namely PC1 and PC2, the variables related to gluten quality formed 4 groups as a function of the stepwise change in the mixing ratio of WW and RB: i) flour protein content, GPI, and GImodif; iiLA-SRC; iii) dietary fibre content and ash content; iv) water, sucrose, and sodium carbohydrate SRCs. However, the modified test procedure should be revised in wheat varieties characterised by a wider spectrum of protein quality, mixed with different types of rye flour (especially wholegrain one).

Effect of onion waste powder on the rheological characteristics, sensory attributes, and antioxidant properties of mayonnaiseOriginal Paper

Tsvetko Prokopov, Kremena Nikovska, Milena Nikolova, Pavel Merdzhanov, Mina Dzhivoderova-Zarcheva

Czech J. Food Sci., 2023, 41(3):182-188 | DOI: 10.17221/19/2023-CJFS


The recovery and utilization of onion processing waste would contribute to the solution of environmental problems. This research presents the way of successful supplementation of onion processing waste in mayonnaise. Different levels (0, 1, 2, and 3%) of onion waste powder (OWP) were used as an additive to mayonnaise, based on sunflower oil. The final mayonnaise formulations were evaluated for sensory properties, rheological behaviour, oxidative stability, total phenolic content, total flavonoids, and antioxidant activity. The results indicated that OWP could be used as a potential health-promoting functional ingredient in amounts of 2% to produce mayonnaise enriched with total phenolic compounds and flavonoids, having high antioxidant activity, acceptable quality, and overall consumer preference.

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 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.

Determination of flavonoids and total polyphenol contents in commercial apple juicesFood Analysis, Food Quality and Nutrition

Leposava PAVUN, Sne¾ana USKOKOVIÆ-MARKOVIÆ, Milena JELIKIÆ-STANKOV, Daniela ÐIKANOVIÆ, Predrag ÐURÐEVIÆ

Czech J. Food Sci., 2018, 36(3):233-238 | DOI: 10.17221/211/2017-CJFS

We propose a sensitive and selective spectrofluorimetric method for the determination of flavonoids as expressed in 'quercetin equivalent' in apple juices. The method is based on the strong emission of the aluminium(III)-quercetin complex at 480 nm with excitation at 420 nm, and it is successfully applied for the determination of flavonoids in commercial apple juices and compared with results obtained in reference spectrophotometric determination. The flavonoid content in commercial apple juices was found to range from 5.53 to 15.55 mg/l quercetin equivalent. The very good agreement between the two methods indicates the suitability of the proposed spectrofluorimetric method for the precise and accurate determination of flavonoids. In addition, the total polyphenol content was determined spectrophotometrically using the Folin-Ciocalteu (FC) method and the antioxidative activity of the tested juices was tested in a DPPH assay and these values were correlated with each other. The obtained profiles of compounds with antioxidative ability lead us to conclude that fruit juice labels based only on fruit % might sometimes misinform consumers.

Selection of drying technology based on dynamic effects on physicochemical properties and flavours of mulberryOriginal Paper

Baolin Han, Shulin Tian, Rong Fan, Rangfang Chen, Yu Wang, Hucheng Gong, Minghong Bian

Czech J. Food Sci., 2023, 41(4):295-303 | DOI: 10.17221/82/2023-CJFS


Mulberry is gaining attention for its potential health benefits. However, post-harvest deterioration of quality necessitates drying to prolong storage. This study aimed to investigate the effects of natural drying (ND), hot air drying (HAD), and vacuum freeze drying (VFD) on bioactive compounds and volatile organic compounds of fresh mulberries. The results showed that VFD had the highest retention of total phenols (5 553.87 ± 744.97 µg GAE·g–1), total flavonoids (3 575.51 ± 465.98 µg rutin·g–1), and total anthocyanins (64.98 ± 13.15 µg C3C·g–1) after prolonged drying. Additionally, flavour was identified as the most important indicator influencing consumer preference for dried mulberries, and VFD was found to be effective in retaining the natural flavours of mulberries. Although thermal treatment leads to a significant loss of organic compounds, HAD showed good retention of active substances and lower energy consumption in a shorter processing time.

Endocrine disruptors in foods: Overlooked factors contributing to the prevalence of obesityReview

Wenli Wu, Yang Yang, Bee KangTan, Shaoling Lin, Yaping Chen, Jiamiao Hu

Czech J. Food Sci., 2023, 41(6):393-405 | DOI: 10.17221/80/2023-CJFS


Endocrine disruptors, also known as endocrine-disrupting chemicals, could mimic or interfere with the body's hormones. Indeed, naturally occurring endocrine disruptors have been widely identified in daily foods. Moreover, industrialisation has resulted in increasing synthetic endocrine disruptors being produced and used as food additives or in food package materials, which makes exposure to endocrine disruptors become more common. Although the safety of synthetic chemicals has been extensively evaluated before entering into the food industry, increasing evidence has also highlighted that long-lasting exposure might influence long-term metabolic outcomes and be associated with the prevalence of obesity. Therefore, this review summarised the sources, detection methods, obesogenic effects and possible mechanisms of endocrine disruptors commonly found in foods, as well as discussed possible underlying mechanisms by which endocrine disruptors contribute to the increased risk of obesity. In conclusion, the review may provide useful information for understanding the association between endocrine disruptors and obesity, which could provide a new angle of view for preventing obesity prevalence.

The state of water is associated with the viability and acidification capacity of Lactobacilli in frozen sourdoughOriginal Paper

Di Chen, Qiang Cheng, Xinxin Xia, Shihua Chen, Changqing Shao, Jing Li, Jinshui Wang, Xingquan Wu

Czech J. Food Sci., 2021, 39(6):435-443 | DOI: 10.17221/82/2021-CJFS

The correlations between water state and the key factors affecting sourdough quality, including cell activity and acidification capacity of lactic acid bacteria (LAB), were established in this study. Results revealed that with the increase of frozen storage time, the cell density (CD), total titratable acidity (TTA), and organic acids content declined, whereas the pH value rose. Further, the freezable water content (FWC) and free water quantity (FWQ) decreased, but the total water loss rate (WLR) and immobilised water quantity (IWQ) increased. The CD showed a highly inversely correlation with WLR, and the pH value was strongly inversely correlated to the FWQ. The confocal laser scanning microscopy (CLSM) observed that the ice crystals had larger volumes during frozen storage. Our data, for the first time, disclosed that the total water content and the FWQ may play a crucial role in maintaining the viability and acidification capacity of LAB in frozen sourdough.

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