Fulltext search in archive



« advanced mode »

 previous    1   2   3   4   5  6   7   8   9   10   11   ...    next 

Results 121 to 150 of 434:

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.

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).

Development of a layered double hydroxides-based air-assisted D-μSPE method in combination with HPLC for the determination of gallic acid in honeyOriginal Paper

Yumei Xiao, Yang Jiang, Tian Liu, Yuanyi Wu, Jialin He, Tian Liu, Yi Yang

Czech J. Food Sci., 2024, 42(2):100-108 | DOI: 10.17221/222/2023-CJFS


Determining gallic acid in honey can provide information for assessing the nutritional value and tracing the source of honey. However, the complex matrix of honey and the low content of gallic acid may hamper the detection. Therefore, it is important to select an appropriate sample preparation method. This work established an air-assisted dispersive micro-solid phase extraction combined with a high-performance liquid chromatography method to determine gallic acid in honey. Zinc/nickel/aluminium layered double hydroxides were selected as the adsorbent to extract gallic acids in diluted honey samples. Under air-assisted extraction, the adsorbents adsorbed gallic acid in honey via anion exchange. Subsequently, the isolated adsorbents were dissolved in a 1% phosphoric acid solution. A high-performance liquid chromatography-UV-Vis detector was used for gallic acid detection. Under the optimised conditions, gallic acid showed good linearity over the concentration range of 0.005–10.0 mg·L–1 with a coefficient of determination greater than 0.999. The detection limit and quantification limit were 13.5 and 45 ng·g–1, respectively. The recoveries were 89.8–93.4%, with the intra-day and inter-day relative standard deviations in the range of 0.71–1.17% and 0.76–1.27%, respectively. The method possesses the advantages of simplicity, rapidity, economy and environmental friendliness and is suitable for detecting gallic acid in honey.

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.

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.

Influence of calcium fortification on the stability of anthocyanins in strawberry pureeOriginal Paper

Eugene Okraku Asare, Novel Kishor Bhujel, Adam Tobolka, Tereza ©korpilová, Helena Èí¾ková, Ale¹ Rajchl

Czech J. Food Sci., 2024, 42(3):207-215 | DOI: 10.17221/164/2023-CJFS

Anthocyanins have received an increased attention not only because of its antioxidant activity; but because fortification of food products by minerals is important due to the lack of some minerals in population. The addition of these minerals can affect the sensorial and nutritional composition of food. The influence of calcium fortification on anthocyanins and colour changes in strawberry puree were assessed by accelerated storage test. The quantification of anthocyanins was performed by high-performance liquid chromatography with diode-array detection (HPLC-DAD) and colour changes were measured spectrophotometrically (CIE L* – lightness, a* – redness, b* – yellowness). The kinetical parameters (velocity constants and activation energies) were calculated. The activation energies of degradation of anthocyanins were calculated as pelargonidin-3-glucoside (26.24 ± 0.57, 21.18 ± 1.07, and 24.53 ± 1.33 kJ·mol–1), cyanidin-3-glucoside (16.10 ± 0.96, 11.61 ± 0.74, and 13.34 ± 1.72 kJ·mol–1), and pelargonidin-3-rutinoside (8.91 ± 0.17, 7.39 ± 0.98, and 8.23 ± 1.72 kJ·mol–1) of the control sample, calcium carbonate and calcium citrate respectively. The results showed that the addition of calcium salt had a statistically significant (P ≤ 0.05) effect on the degradation of anthocyanins.

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.

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.

Quality characterisation of cake glazes containing tropical fruit seed powdersOriginal Paper

Nurulhuda Md. Salleh, Norazlin Abdullah, Nurulain Syuhada Mohamad Yazid, Norhayati Muhammad

Czech J. Food Sci., 2024, 42(4):235-242 | DOI: 10.17221/54/2024-CJFS


This study aims to characterise the physicochemical properties and stability of confectionery glazes made from various tropical fruit seed powders during storage. Physicochemical properties were evaluated at regular intervals throughout frozen storage to monitor quality changes. The mango seed glaze is slightly acidic, and significantly darker, with tones of green and blue. The glaze has a total soluble solid content of 73.37 °Brix, a moisture content of 19%, hardness of 46.69 g, and sagging capacity of 18.33 mm, which ensures both structural integrity and sensory appeal. Its highest viscosity among formulations suggested possible thickening and improved stability. Over 28 days, significant changes occur, with the pH stabilising to a near-neutral 6.8. The hue changes over time, migrating towards reddish tone as indicated by increasing positive a* values, while maintaining a consistent preference for blue-toned hues with continuously negative b* values. Moisture levels remained stable at 18.71% during storage, with minimal total soluble solid content changes, indicating sustained quality. The findings suggest that mango seed glazing is a viable option for quality preservation during storage. This study provides essential empirical insights into the potential changes in the quality characteristics of various fruit seed glazes when subjected to freezing.

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.

Enriching wheat flour with grape pomace powder impacts a snack's chemical, nutritional, and sensory characteristicsOriginal Paper

Amal Hassan Alshawi

Czech J. Food Sci., 2024, 42(4):243-250 | DOI: 10.17221/103/2024-CJFS


Because grape pomace powder (GPP) contains abundant phenolic chemicals and fibres, GPPs can serve as a filler in developing novel food products. This study examined how the GPP amounts affected a composite flour's physicochemical properties and bakery snacks' chemical, technical, and sensory properties. The experimental procedure involved replacing wheat flour (WF) with GPP at 5–20% while maintaining 100% WF as the control. The addition of GPP resulted in a significant decrease in the oil absorption capacity (P ≤ 0.05), while the rehydration index and water absorption capacity increased (P ≤ 0.05). The peak length (5.44–5.90 min), pasting temperature (70.20–80.92 °C), peak viscosity (124.72–172.80 RVU; RVU – relative value unit), trough viscosity (60.76–82.04 RVU), breakdown viscosity (69.56–93.74 RVU), final viscosity (162.70–222.30 RVU), and setback viscosity were measured. The addition of GPP to the composite flour and snacks decreased the lightness (L*) and increased the redness (a*) and yellowness (b*). The items' higher dietary fibre (DF) allowed them to claim 'high fibre content' when the maximum GPP was added. The GPP also increased the snacks' total solids, protein, ash, fibre, total phenolics content (TPC), and antioxidant capacity. The sensory acceptability of the snacks made with 5–10% GPP instead of WF was higher.

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.

Optimisation of the inhibitory effect of Lactiplantibacillus plantarum, nisin, and lysozyme to prevent the late blowing defect in a cheese modelOriginal Paper

Sinan Akbal, Zübeyde Öner

Czech J. Food Sci., 2024, 42(5):330-339 | DOI: 10.17221/78/2024-CJFS


The present study employed response surface methodology (RSM) to optimise the prevention of late blowing defects in cheese during storage. The aim was to enhance the inhibition of Clostridium sporogenes in cheese by manipulating three independent variables: Lactiplantibacillus plantarum (utilising two different strains, labelled as A and B, the total cheese inoculation rate was 2% overall and the A : B ratio ranging from 25% to 75%), and lysozyme (ranging from 0 to 0.2 mg·L–1). The response variables considered in this model cheese study included the Clostridium count, pH, and titratable acidity. The results showed that the optimal conditions for inhibiting C. sporogenes and preventing late blowing defects in cheese were achieved with an L. plantarum A : B ratio of 49.54 : 50.46%, nisin at a concentration of 1.762 mg·L–1, and lysozyme at 0.2 mg·L–1. These results demonstrated not only effective inhibition of C. sporogenes, a pivotal contributor to late blowing defects in cheese but also indicated favourable outcomes in terms of acidity parameters, which are crucial quality criteria for cheese production. The application of Response Surface Methodology revealed that late blowing defects can be prevented using relatively lower concentrations of antimicrobial agents, along with a judicious selection of appropriate cultures. This research highlights the potential for more efficient and cost-effective strategies to maintain cheese quality by minimising the risk of late blowing defects.

Edible chitosan in preserving the quality and shelf life of fresh-cut mango (Mangifera indica L.)Original Paper

Afrina Rahman, Nehar Parvin, Md. Harun Rashid, Jayanta Roy, Md. Arif Sakil, Farzana Ferdoush, Samar Kumar Guha, Nigar Sultana Parvin, Mubarak Ahmad Khan, Md. Abdul Kader

Czech J. Food Sci., 2024, 42(5):340-352 | DOI: 10.17221/104/2024-CJFS


Mango (Mangifera indica) is extremely perishable with a short shelf life that limits its marketability. Chitosan may extend mango storage by preventing moisture loss and gaseous exchange while preserving the nutritional quality. Therefore, the current study was designed to assess the effect of chitosan on the shelf life and quality of fresh-cut mangoes. Manually cubed mango was dipped into 0 (control), 10, 15, 20, 30, and 50 ppm chitosan solution in airtight jar and stored at ambient (25–28 °C) and refrigeration (4 °C) condition. Changes in various microbial, physical, and chemical characteristics were documented to evaluate the effectiveness of treatments in prolonging and sustaining the freshness and quality of mango. Treated mangoes significantly retarded growth of total mold and bacterial counts compared to the control sample in both storage conditions and found it lower under refrigeration. Likewise, chitosan also preserved various fruit quality attributes to a significant extent by retaining vitamin C, fat, titratable acidity, soluble sugar, and protein. However, the refrigerator stored mangoes have better ability to retard moisture loss and drop in sensory quality. Among the other solutions, 10 ppm chitosan solution exhibited better performance in reducing perishability of mango while maintaining prolonged shelf life and quality attributes. Overall, the findings revealed that chitosan solution at low temperature effectively preserves mango quality during storage and offers promising approach for the successful commercialisation of chitosan as a natural preserver for mango sellers and consumers to prolong shelf life.

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.

Effect of acetic acid immersion on the taste and aroma quality of immature Robusta coffee beansOriginal Paper

Deden Fardenan, Dian Angraini Suroto, Supriyadi Supriyadi

Czech J. Food Sci., 2024, 42(6):391-404 | DOI: 10.17221/60/2024-CJFS


The presence of immature coffee beans reduces the quality of the coffee brew. This study evaluated how the acetic acid affected the aroma and taste of immature compared to mature Robusta coffee. The naturally processed immature Robusta green beans were immersed in acetic acid (0–5%) for 30–90 min. The naturally processed mature Robusta green beans were used as a control treatment. The samples were roasted at a medium level (240 °C, 14 min). The sensory analysis was evaluated by the cupping test by a trained and certified panellist (Q-Grader). Acetic acid immersion significantly improved the sensory quality of immature beans (P < 0.05). Specifically, immersion in 3% acetic acid for 90 min yielded the highest sensory score of 84.92. According to the Coffee Quality Institute (CQI) classification, this score falls into the 'Fine' Robusta classification. The 0% 30-min, 3% 30-min, and 3% 90-min treated immature samples and an untreated control mature sample were analysed for pH, caffeine, chlorogenic acid, and volatile compounds. The treatment significantly decreased the chlorogenic acid (P < 0.05) and increased the volatile compound concentration of furans, ketone, pyrrole, aldehyde, and ester while decreasing pyrazines, sulphur, phenol, and alcohol. This study effectively enhanced immature Robusta taste and aroma quality to a degree comparable with mature Robusta coffee beans.

Kinetics and mathematical models of date paste dried using a convective infrared dryerOriginal Paper

Mahmoud Younis, Khaled Abdel Wahed Ahmed, Isam Ali Mohamed Ahmed, Hany Mohamed Yehia, Diaeldin Omer Abdelkarim, Ahmed Elfeky

Czech J. Food Sci., 2024, 42(6):465-475 | DOI: 10.17221/66/2024-CJFS


Achieving the desired level of caramelisation in a date powder requires considerable effort. Consequently, an assessment was conducted on efficacy of thin-layer infrared dehydration for date paste. Various parameters were considered, including airflow velocities of 0.5, 1.0, and 1.5 m·s–1, radiation intensities of 0.076, 0.1528, and 0.228 W·cm–2, and date paste layer thicknesses of 3 mm and 5 mm. The study's findings indicated a positive correlation between drying rate and lowering airflow velocity and a negative correlation between drying time and decreasing airflow velocity, the thickness of date paste, and rising intensity of infrared. The effective moisture diffusivity (Deff) was caculated by employing Fick's diffusion equation. For all situations under investigation, the mean values were within the range of 3.94 × 10–11 m2·s–1 to 6.01 × 10–10 m2·s–1. A relationship has been established between Deff and moisture content. Seven distinct mathematical models were subjected to rigorous validation by applying non-linear regression analysis, aiming to accurately characterise the drying process of date paste. The modified two-term model provided the most accurate forecast of the drying process for date paste layers.

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.

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.

Application predictive modelling of Penicillium roqueforti germination in environmental conditions in cakeOriginal Paper

Hassan Nakhchian, Farideh Tabatabaee Yazdi, Seyed Ali Mortazavi, Mohebat Mohebi

Czech J. Food Sci., 2025, 43(1):8-16 | DOI: 10.17221/84/2024-CJFS

This study aimed to predict the germination of Penicillium roqueforti as one of the most important moulds in cake in certain environmental conditions that lead to cake spoilage. The germination rate of P. roqueforti was evaluated by culturing in the Yeast Extract Glucose Chloramphenicol Agar medium with different pH, water activity (aw), and inoculum size at three levels of temperature (15, 25, 30 °C) during 60 days by the factorial experiment. The results of analysis of variance (ANOVA) proved that environmental conditions affect germination significantly (P < 0.05). Predictive modelling illustrated that the temperature did not affect germination significantly, while no germination was seen at aw = 0.65. The minimum lag phase of germination was observed at aw = 0.9, pH = 6.5, and inoculum size of 1 000 spores per mL. The logistic model was found to be more precise for fitting the data of P. roqueforti in cakes.

Influence of the tea polyphenol treatment on the colour, texture, and antioxidant activity in fresh-cut potatoesOriginal Paper

Yang Gao, Yu-Chao Zhao, Cheng-Kun Jiang, Chao-Nan Kan

Czech J. Food Sci., 2025, 43(1):29-36 | DOI: 10.17221/139/2024-CJFS


This study evaluated the quality changes of fresh-cut potatoes during storage by treating with different concentrations of tea polyphenol (0.125, 0.25, 0.5, and 1.0 g·L–1). During the storage, the ∆E value (colour change of fresh-cut potatoes), browning degree, chewiness, malondialdehyde (MDA) content, polyphenol oxidase (PPO) and peroxidase (POD) activity gradually increased. But the hardness and elasticity first increased and then decreased. Compared with the control, the tea polyphenol treatment could effectively inhibit the increase of ∆E value, browning degree, chewiness, MDA content, PPO and POD activity of potato slices, and delay the decrease of slice hardness, elasticity and brittleness in the later storage period. Among them, 0.25 g·L–1 tea polyphenol has the best effect. It can maintain the colour of fresh-cut potatoes, inhibit the increase of PPO and POD active enzyme activities, reduce the production of browning substances, and improve the storage quality of fresh-cut potatoes.

Studies on some engineering properties of breadfruit (Artocarpus altilis) starch flourOriginal Paper

Waliu Adewale Adebayo, Mercy Oluwakemi Ademiju, Dahunsi Olamide Fajobi

Czech J. Food Sci., 2025, 43(2):105-111 | DOI: 10.17221/40/2023-CJFS

This research work evaluated some engineering properties of breadfruit starch flour following standard procedures with the aim of providing engineering data that would help its usage in food processed industries. Starch was extracted from matured breadfruit fruits, modified using acid and engineering properties were examined following standard procedures. Results of moisture contents, loose and packed bulk densities, density ratio and porosity were ranged from 8.23–9.13% dry basis (DB); 0.44–0.51 g·mL–1; 0.60–0.66 g·mL–1; 70.01–80.14% and 19.87–29.99%, respectively. Similarly, Carr index values ranged from 19.44–30.61% and Hausner ratio values ranged from 1.25–1.43, indicating that the flour samples investigated had poor (native), fair (modified) and good (potato) flow properties, using Carr index standard. Amylose, amylopectin and amylose-amylopectin ratio contents values ranged from 21.52–29.77%; 70.23–78.48% and 0.28–0.42%, respectively. Also, the flour samples thermal properties values using Differential Scanning Calorimeter (DSC) ranged from 106.4–129.09 °C; 31.93–78.36 °C; 106.2–175.75 °C; 214.90–278.6 J·g–1; 35.5–148.82 °C; 2.26–10.95 J·g–1·K–1; 0.305–3.0 (×10–6) W·m–1· °C–1, and 0.095–1.32 (×10–6) m2·s–1 for peak temperature, onset temperature, end temperature, enthalpy, temperature range, specific heat capacity, thermal conductivity and thermal diffusivity, respectively. Viscosity values as influenced by concentration and temperature ranged from 25.8–149 mPas for native starch and 41.9–109.6 mPas for modified starches. Hence, this research work provides engineering data that would help in process control, process design and bulk handling of breadfruit starch flour so as to promote its usage in food process industries.

Sensory properties of pork sausage after sea buckthorn extract additionOriginal Paper

Marek Bobko, Luká¹ Jurèaga, Alica Bobková, Al¾beta Demianová, Melina Korèok, Judita Lidiková, Miroslav Kroèko, Ondøej Buèko, Andrea Mendelová, Terézia ©vecová, Andrea Mesáro¹ová

Czech J. Food Sci., 2025, 43(5):320-325 | DOI: 10.17221/11/2025-CJFS

The meat industry is actively trying to replace synthetic antioxidants with natural counterparts. Sea buckthorn is an excellent source of polyphenols and its high antioxidant properties. Various authors tested the antioxidation effect of sea buckthorn on lipids in meat products. The problem of sea buckthorn addition to food is its effect on sensory parameters. Our study incorporated sea buckthorn extract into pork sausage, stored for 21 days, and observed sensory properties and their changes. We mechanically measured the pH, colour, and textural properties of pork sausage samples with minimal variability observed. Also, sensory analysis by informed panellists was conducted on multiple storage days. Sensory evaluation revealed significant deterioration of sensory quality. Sea buckthorn remains an interesting option for the meat industry. However, further multidisciplinary research is still needed.

Gastric survival of lactic acid bacteria in probiotic-labelled products from the Turkish market: An in vitro studyOriginal Paper

Gizem Özlük, Gabriela Krausová

Czech J. Food Sci., 2025, 43(5):344-351 | DOI: 10.17221/36/2025-CJFS

The resilience of lactic acid bacteria (LAB) in commercial probiotic products remains a critical area of investigation, particularly regarding their capacity to survive the harsh gastric environment. Scientific guidelines indicate that at least 6 log CFU·g–1 of viable probiotics must reach the intestines to achieve therapeutic benefits, which often requires an initial concentration of 8–9 log CFU·g–1 in the product. However, national regulations may specify lower thresholds; for example, Turkish Food Legislation requires 6 log CFU·g–1 for probiotic products and 7 log CFU·g–1 for kefir products. This study evaluates the in vitro gastric survival of LAB in 20 probiotic-labelled foods and 5 supplements available in the Turkish market using a simulated gastric model. Results reveal that 75% of the marketed probiotic-labelled foods comply with their label claims. Additionally, 55% of the samples demonstrate LAB strains fully resistant to gastric acidity. Dairy-based products exhibit significantly better survival rates under simulated gastric conditions compared to supplements, highlighting their potential for enhanced therapeutic efficacy.

Enhancing rheological properties of dough and quality of potato fibre-enriched breadOriginal Paper

Omar Saleh, Hossam S. El-Beltagi, Abdelrahman R. Ahmed, Hefnawy Taha, Haiam O. Elkatary, Abdalla El‐Hadary, Hoda A.S. Farag, Mahmoud Sitohy, Ahmed Mahmoud Ismail, Ali Osman

Czech J. Food Sci., 2025, 43(6):462-469 | DOI: 10.17221/29/2025-CJFS

This study investigates the effect of varying concentrations of potato fibre (PF) (1, 2, and 3%) on wheat flour (WF) dough rheological properties and the resultant pan bread quality. Chemical analysis, physical characteristics (weight, loaf volume, and specific volume), and colour attributes were estimated to assess bread quality. The impact of PF on bread sensory evaluation was estimated. The addition of PF significantly affected the properties of the dough. Moreover, the data indicated a substantial increase in water absorption (P ≤ 0.05) from 57.2% for the control to 65.5, 73.3, and 77.6% with the addition of 1, 2, and 3% PF to WF, respectively. Protein, crude fibre, and ash levels significantly increased (P ≤ 0.05) with higher PF ratios. Moisture and carbohydrate contents were markedly reduced (P ≤ 0.05). The specific volume considerably decreased from 3.15 cm3·g–1 in the control to 2.9, 2.74, and 2.53 cm3·g–1 with the addition of 1, 2, and 3% PF to WF, respectively. All replacement samples exhibited no significant alterations (P ≤ 0.05) in L* values and substantially (P ≤ 0.05) increased values of yellowness (b*) in all fortified samples relative to the control. Sensory assessments revealed that PF can be incorporated into WF at concentrations of 1% and 2% without compromising the overall acceptability of bread compared to the control.

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.

Monitoring of gluten in Czech commercial beersShort Communication

Marek Pernica, Rastislav Bo¹ko, Zdenìk Svoboda, Karolína Bene¹ová, Sylvie Bìláková

Czech J. Food Sci., 2020, 38(4):255-258 | DOI: 10.17221/61/2020-CJFS

Between 2014 and 2019, a total of 361 commercially available Czech beer samples (103 brands) were analysed for gluten content using a competitive enzyme immunoassay. The gluten levels in different types of beers ranged from < 10 mg L-1 to 3 380.0 mg L-1. The percentage of samples that can claim the gluten-free status (< 20 mg L-1) were in categories gluten-free (99%), radler (84.6%), non-alcoholic beer (44.2%), lager beer group I (16.6%), lager beer group II (16.3%), special beer (25%) and wheat beer (0%). The important finding from this work was that 2 out of 196 beer samples with a gluten-free label contained more gluten than allowed under the guidelines established by the European Union and the Codex Alimentarius Standard. From a consumer point of view, it is also significant that in addition to gluten-free samples, 15.4% of radlers, 55.8% of non-alcoholic beers, 71.4 to 75.5% of all lagers and 66.6% of special beer samples could be labelled as very low gluten (21-100 mg L-1).

Appraisal of antioxidant potential and biological studies of bogan bail (Bougainvillea glabra) leaf extracts using different solventsOriginal Paper

Muhammad Riaz, Humaira Fatima, Muhammad Misbah ur Rehman, Rahman Qadir, Shabbir Hussain, Abdul Hafeez, Abu Bakar Siddique

Czech J. Food Sci., 2021, 39(3):176-180 | DOI: 10.17221/273/2020-CJFS

Current research work was performed to evaluate the antioxidant, antidiabetic, thrombolytic, and cytotoxic potential of Bougainvillea glabra leaf extracts with different solvents. Extraction of leaves was carried out by maceration using solvents of various polarity such as n-hexane, chloroform, ethyl acetate, n-butanol, and methanol. The highest values of total phenolic and flavonoid contents were assessed in methanolic extract, such as 58.57% and 29.41%, respectively. Antioxidant potential was measured by DPPH free radical, showing 65.16% scavenging activity in methanolic extract. Similarly, the reducing power of methanolic extract was also measured. Hemolytic activity of B. glabra leaf extracts was evaluated, and maximum percentage lysis was found as 6.86% in chloroform extract. The thrombolytic activity of B. glabra leaf extracts was evaluated against human red blood cells, and the maximum percentage of clot lysis was 59.10% in chloroform extract. Maximum antidiabetic activity (16.20%) was observed in methanolic extract. Overall, the presented results reveal that bogan bail extract is capable of being employed in nutra-pharmaceutical industry.

Chemical comparison of 100% apple, orange and grapefruit juices directly pressed and made from concentrateOriginal Paper

Ivo Soural, Petr ©nurkoviè, Monika Bieniasz

Czech J. Food Sci., 2022, 40(1):69-75 | DOI: 10.17221/194/2021-CJFS

One hundred per cent apple, orange and grapefruit juices were analysed for ascorbic acid (AA) content, total polyphenolic content (TPC), and other parameters: titratable acids (TA), malic acid (MA), citric acid (CA), volatile acid (VA), soluble solids (SS), density, and the content of free amino acid as formol number (FN). Some apple juices on the Czech market contain added vitamin C, and the AA content of such juices (268-632 mg L-1) is several times higher than that of apple juices without added vitamin C (around 50 mg L-1). Therefore, the enriched apple juices had a vitamin C content comparable to citrus fruit juices (orange and grapefruit). All contents were compared separately for juices made from concentrate and for directly pressed juices. The effect of the production method was statistically significant (P < 0.05) only for TPC in apple juices, where it was major [473 ± 136 mg gallic acid equivalents (GAE) L-1 from concentrate vs. about twice the value of 798 ± 193 mg GAE L-1 in directly pressed juice], and only to a smaller extent for TA in grapefruit juices (12.5 ± 0.8 g L-1 from concentrate, which was about 30% more than in directly pressed juice).

Polyamines in plasma membrane function in melatonin-mediated tolerance of apricot fruit to chilling stressOriginal Paper

Qiyao Dong, Huaipan Liu, Ronald Kurtenbach

Czech J. Food Sci., 2022, 40(4):313-322 | DOI: 10.17221/74/2022-CJFS

Polyamines are closely associated with environmental stresses and melatonin pretreatment enhances the resistance of fruit to chilling stress. However, a mechanism underlying melatonin-mediated chilling resistance remains to be answered. This research aimed to illuminate whether polyamines would be involved in melatonin-mediated chilling resistance. Therefore, in the experiment, the polyamines conjugated to the plasma membrane from the melatonin-pretreated apricot flesh cell were examined under chilling stress. Chilling resistance was judged by four parameters: fruit browning degree, plasma membrane permeability, malondialdehyde content and plasma membrane protein sulfhydryl level. Results showed melatonin pretreatment led to obvious rises in the levels of non-covalently conjugated spermine and spermidine, and covalently conjugated putrescine and spermidine in the plasma membrane. Methylglyoxyl-bis (guanylhydrazone) pretreatment could inhibit the melatonin-induced increases of non-covalently conjugated spermidine and spermine by inhibiting S-adenosylmethionine decarboxylase (SAMDC) activity and free spermidine and spermine contents in flesh, coupled with the decrease in chilling resistance. Similarly, phenanthroline pretreatment could inhibit the melatonin-induced increases in covalently conjugated putrescine and spermidine in the plasma membrane through inhibiting transglutaminase (TGase) activity and simultaneously could aggravate chilling damage. The results suggested melatonin pretreatment could enhance chilling resistance by increasing non-covalently conjugated spermidine and spermine, as well as covalently conjugated putrescine and spermidine in the plasma membrane of apricot fruit.

 previous    1   2   3   4   5  6   7   8   9   10   11   ...    next