Effect of milk origin on proteolysis and accumulation of biogenic amine during ripening of Dutch-type cheese

Dairy products from goat's milk are characterized by their distinctive aroma and their specific taste. However, the strong aroma can discourage some consumers. Properties of cheese can be modified by the combination of goat's and cow's milk. On the other hand, chemical diversity from different milk origin may affect the changes during ripening. The aim of the study was to compare the intensity of changes during ripening of model cheese samples produced with various ratios of goat's and cow's milk. The combinations 100:0 (100% goat's milk), 75:25, 50:50, 25:75 and 0:100 (100% cow's milk) were used for the manufacture of Dutch-type cheeses, which were ripened during a period of 84 days. Protein profile, free amino acid content and biogenic amine content were used for the description of cheese properties during storage. Cluster analysis showed different changes in the protein matrix of the examined samples. The results indicated that even low addition of cow's milk significantly affected the protein profile. However, the homology of protein profiles rose with the increasing ripening time. More intensive proteolysis occured in the samples with predominance of goat's milk. Moreover, cheese samples produced only from goat's milk presented a significant increase inthe amount of free amino acids after 14 days of ripening. The effect of milk origin on the production of biogenic amines was also examined. However, higher concentrations of biogenic amines were detected in samples manufactured from goat's milk. Tyramine, putrescine, histamine and phenylethylamine were detected during the storage of the samples. The total biogenic amine content exceeded 100 mg/kg in samples with predominance of goat's milk. © 2017 Potravinarstvo Slovak Journal of Food Sciences

Preparation of malts for production of special beers

The article deals with production of various malts intended for manufacture of special types of beer. The malts were used to brew samples of beer with alcoholic strength ranging between 8 - 12% EPM. The above range of original wort content was chosen due to its suitability for sensory evaluation and properties; in stronger types of beer, (more than 12% EPM), nature of the beverage can be drown by mashy flavour. In the experimental samples, the actual residual extract oscillated between 4.0 - 6.5%. The content of ethanol corresponded to the degree of fermentation and thereby also to the residual actual extract in balance equilibrium specifying that higher residual extract corresponds to lower content of alcohol by volume. It ranged between 2.5 - 5.0%. The sample 1 contained the highest amount of ethanol by mass (3.9%) and the sample 13 showed the lowest one (1.9%); alike trend of ethanol content by volume was revealed (5 and 2.44%, respectively). The highest content of actual and apparent extract was found in the sample 2 (6.6 and 5.2%, respectively); the sample 13 showed the lowest levels (4.0 and 3.1%, respectively). The original wort extract content averaged 9.9% in most of the samples; the sample 1 showed distinctly higher value (12.6%) and, on the contrary, the sample 13 demonstrated the lowest one (7.4%). The highest relative density was revealed in the sample 2 (1.02%) and the lowest one in the sample 13 (1.01%). Considering differences in osmotic pressure, the sample 1 exhibited the highest value (1045 mOs) and the sample 13 the lowest one (551 mOs). The highest level of fermentation was found in the sample 19 (61.7%), the lowest one was proved in the sample 19 (44.0%). Sensory analysis corresponded to originality and characteristics of each sample. The sample of beer made from spring barley was evaluated to be the best one. © 2017 Potravinarstvo Slovak Journal of Food Sciences

Facile HPLC technique for simultaneous detection of estrogentic hormones in wastewater

The ever-increasing population has aroused demand for contraceptive chemicals which pollute the water reservoirs through industrial effluents. This has caused a severe threat to marine life and high concern about the availability of fresh drinkable water for people all over the world. Not only this, the unwanted intake of these water containing hormones leads to fertility disorder, rapid femininity, loss in male sperm count, high chances of breast, and ovarian cancer. Therefore, in this study, a one-step high-pressure liquid chromatography (HPLC) technique was devised for simultaneous detection and quantification of various estrogenic hormones from wastewater. Four representative hormones Estrone (E1), β-Estradiol (E2), Estriol (E3), and 17a- Ethinylestradiol (EE2) were used. To address the solubility of these hormones, a study was conducted in three solvents systems viz. ethanol, ethanol: water (20:80), and water, respectively. Similarly, calibration curves were made for these three solvent systems with regression coefficients =0.99. Interestingly, it was found that water can be used as a solvent for the estrogenic hormones at a detection limit as low as 5 μg/L, which makes this study quite significant. © 2021 TANGER Ltd., Ostrava.Internal Grant Agency from the Centre of Polymer System (CPS), Tomas Bata University in Zlin, Czech Republic [IGACPS2020002]Univerzita Tomáše Bati ve Zlín

Green synthesis of titanium and zinc oxide nanoparticles for simultaneous photocatalytic removal of estrogens in wastewater

This study reports on the green synthesis of titanium and zinc oxide nanoparticles (ZnO-NPs) using lemon juice and peel extract, zinc acetate, ethylene glycol, and titanium IV isopropoxide as precursors. The prepared TiO2 and ZnO-NPs were characterized via X-ray Diffraction analysis, UV-vis spectroscopy, dynamic light scattering, scanning electron microscopy, and EDAX. The as-prepared samples, TiO2 and ZnO-NPs, were further subjected for the photocatalytic degradation of estrogenic hormones (Estrone, Estradiol, Ethinylestradiol, and Estriol) under UV light irradiation at 365 nm, which resulted in promising photocatalytic activity. All four hormones were significantly degraded owing to the photocatalytic activity combined with a slight contribution (4-11 %) from the hormonal adsorption onto the surface of the photocatalysts. Overall hormonal degradation rates in the range of 84-93 % and approximately 99 % were achieved in 60 minutes under UV light irradiation by ZnO and TiO2, respectively. © 2021 NANOCON Conference Proceedings - International Conference on Nanomaterials. All rights reserved.Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT: IGACPS2021002, RP/CPS/2020/002; Univerzita Tomáše Bati ve Zlín

Effect of an antioxidant based on red beetroot extract on the abiotic stability of polylactide and polycaprolactone

This study investigated the effect of natural antioxidants inherent to beetroot (Beta vulgaris var. Vulgaris) on the ageing of environmentally friendly plastics. Certain properties were examined in this context, comprising thermal, mechanical, and morphological properties. A visual evaluation of relevant changes in the given polymers (polylactide and polycaprolactone) was conducted during an ageing test in a UV chamber (45◦C, 70% humidity) for 720 h. The films were prepared by a casting process, in which samples with the extract of beetroot were additionally incorporated in a common filler (bentonite), this serving as a carrier for the extract. The results showed the effect of the incorporated antioxidant, which was added to stabilize the biodegradable films. Its efficiency during the ageing test in the polymers tended to exceed or be comparable to that of the reference sample. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Ministry of Education, Youth, and Sports of the Czech RepublicMinistry of Education, Youth & Sports - Czech Republic [RP/CPS/2020/002]; Internal Grant Agency of TBU in Zlin [IGA/CPS/2020/002]IGA/CPS/2020/002; Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT: RP/CPS/2020/00

Detection and relative quantification of amine oxidase gene (yobN) in Bacillus subtilis: application of real-time quantitative PCR

Degradation of undesirable biogenic amines (BAs) in foodstuffs by microorganisms is considered one of the most effective ways of eliminating their toxicity. In this study, we design two sets of primers for the detection and quantification of the amine oxidase gene (yobN) and endogenous (housekeeping) gene (gyrB) in Bacillus subtilis. Moreover, these sets can be used for relative quantification of yobN by real-time PCR (qPCR). We also tested the degradation of BAs by three bacterial strains (B. subtilis strains: IB1a, CCM 2216, CCM 2267) in a mineral medium over a two-day period. Their degradation abilities were verified by high performance liquid chromatography with UV detection (HPLC/UV). According to the results, two strains significantly (P < 0.05) reduced histamine, tyramine, putrescine, and cadaverine. Moreover, our results indicate that the degradation ability of B. subtilis strains could be limited by sporulation because the gene encoding amine oxidase (yobN) is no longer expressed in the spores. © 2021, Association of Food Scientists & Technologists (India).Grant Agency of the Czech Republic (GACR)Grant Agency of the Czech Republic [17-09594S]; Internal Grant Agency of the Tomas Bata University in Zlin [IGA/FT/2020/009]Grantová Agentura České Republiky, GA ČR: 17-09594S; Univerzita Tomáše Bati ve Zlíně: IGA/FT/2020/00

Non-edible parts of Solanum stramoniifolium Jacq. - a new potent source of bioactive extracts rich in phenolic compounds for functional foods

Extracts prepared from leaves, roots, and stems of Solanum stramoniifolium Jacq. (Solanaceae) in 80% ethanol have been tested for their in vitro antioxidant, anti-inflammatory, antimicrobial, and cytotoxic activities with an aim to find new sources of substances for functional foods and food additives. The root extract revealed the highest antioxidant activity in all assays exceeding the trolox capacity, and was the only extract that inhibited nitric oxide production in mouse macrophage cells, showing also the capacity to suppress the growth of all tested human tumor cell lines (MCF-7, NCI-H460, HeLa and HepG2). The leaf extract showed the strongest antimicrobial activity inhibiting all tested clinical isolates. To the author's best knowledge it was the first time that all individual parts of this plant were tested for biological activity together with the phenolic compound characterization.Foundation for Science and Technology (FCT, Portugal) [UID/AGR/00690/2013, SFRH/BPD/107855/2015, SFRH/BPD/101413/2014, SFRH/BPD/BPD/68344/2010]; FEDER [UID/AGR/00690/2013, SFRH/BPD/107855/2015, SFRH/BPD/101413/2014, SFRH/BPD/BPD/68344/2010]; FEDER, through POCI-COMPETE [POCI-01-0145-FEDER-006984]; FCT [POCI-01-0145-FEDER-006984]; Internal Grant Agency of Tomas Bata University in Zlin [IGA/FT/2016/003]POCI-01-0145-FEDER-006984, CIMO, Kansainvälisen Liikkuvuuden ja Yhteistyön Keskus; POCI-COMPETE2020, FCT, Fundació Catalana de Trasplantament; SFRH/BPD/101413/2014, CIMO, Kansainvälisen Liikkuvuuden ja Yhteistyön Keskus; SFRH/BPD/107855/2015, CIMO, Kansainvälisen Liikkuvuuden ja Yhteistyön Keskus; SFRH/BPD/BPD/68344/2010, CIMO, Kansainvälisen Liikkuvuuden ja Yhteistyön Keskus; UID/AGR/00690/2013, CIMO, Kansainvälisen Liikkuvuuden ja Yhteistyön Keskus; FEDER, Federación Española de Enfermedades Rara

Polylactide/polyvinylalcohol-based porous bioscaffold loaded with gentamicin for wound dressing applications

This study explores the feasibility of modifying the surface liquid spraying method to prepare porous bioscaffolds intended for wound dressing applications. For this purpose, gentamicin sulfate was loaded into polylactide-polyvinyl alcohol bioscaffolds as a highly soluble (hygroscopic) model drug for in vitro release study. Moreover, the influence of inorganic salts including NaCl (10 g/L) and KMnO4 (0.4 mg/L), and post-thermal treatment (T) (80◦ C for 2 min) on the properties of the bioscaffolds were studied. The bioscaffolds were characterized by scanning electron microscopy, Fourier Transform infrared spectroscopy, and differential scanning calorimetry. In addition, other properties including porosity, swelling degree, water vapor transmission rate, entrapment efficiency, and the release of gentamicin sulfate were investigated. Results showed that high concentrations of NaCl (10 g/L) in the aqueous phase led to an increase of around 68% in the initial burst release due to the increase in porosity. In fact, porosity increased from 68.1 ± 1.2 to 94.1 ± 1.5. Moreover, the thermal treatment of the Polylactide-polyvinyl alcohol/NaCl (PLA-PVA/NaCl) bioscaffolds above glass transition temperature (Tg ) reduced the initial burst release by approximately 11% and prolonged the release of the drug. These results suggest that thermal treatment of polymer above Tg can be an efficient approach for a sustained release. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Ministry of Education, Youth, and Sports of the Czech RepublicMinistry of Education, Youth & Sports - Czech Republic [RP/CPS/2020/002]; Internal Grant Agency of TBU in Zlin [IGA/CPS/2020/002]IGA/CPS/2020/002; Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT: RP/CPS/2020/00

ZnO/Cu2O heterojunctions treated glass surface for photocatalytic and self-cleaning applications

Here we report the synthesis route for glass surface functionalization by ZnO nanorods and nanowires-based Cu2O heterojunction. In the first step, ZnO elongated structures were grown on a seeded substrate following the classic hydrothermal method, and their thickness can be controlled by polyethyleneimine (PEI) concentration. In the second step, ZnO/Cu2O heterojunctions were fabricated by immersion of ZnO-grown substrate upside-down into the copper sulfate solution with glucose as a reducing agent. After characterization of prepared ZnO/Cu2O heterojunction by SEM, TEM, and XRD, its application capability for waste-water treatment was successfully demonstrated on Estriol (E3) hormone degradation under UV light by using a continuous Drip Flow Biofilm Reactor. Furthermore, functionalized glasses were shown to be effective for designing self-cleaning surfaces. The photocatalytic-induced self-cleaning ability was demonstrated by resazurin-based smart ink and tert-butyl alcohol-based methylene blue ink. © 2023 TANGER Ltd., Ostrava.Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT: LTT20010, RP/CPS/2022/00

Design and fabrication of electrospun PLA-based silica-modified composite nanofibers with antibacterial properties for perspective wound treatment

The aim of this study was to develop a novel amikacin (AMI) delivery system with prolonged release based on composite electrospun nanofibers of PLA supplemented with AMI-loaded Si nanoparticles of different morphology. The resultant materials were characterized in terms of their physical properties (scanning electron microscopy, Brunauer-Emmett-Teller analysis, thermogravimetric analysis, water contact angle). High-Performance Liquid Chromatography was used to determine the AMI content in the liquid fractions obtained from the release study. The results show that nanofibers of fumed silica exhibited an aggregated, highly porous structure, whereas nanofibers of mesoporous silica had a spherical morphology. Both silica nanoparticles had a significant effect on the hydrophilic properties of PLA nanofiber surfaces. The liquid fractions were investigated to gauge the encapsulation efficiency (EE) and loading efficiency (LE) of AMI, demonstrating 66% EE and 52% LE for nanofibers of fumed silica compared to nanofibers of mesoporous silica nanoparticles (52% EE and 12.7% LE). The antibacterial activity of the AMI-loaded nanofibers was determined by the Kirby-Bauer Method. These results demonstrated that the PLA-based silica nanofibers effectively enhanced the antibacterial properties against the Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae.TBU in Zlin, (IGA/CPS/2023/002); Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT, (RP/CPS/2022/002, RP/CPS/2022/007)Ministry of Education, Youth and Sports of the Czech Republic [RP/CPS/2022/002, RP/CPS/2022/007]; Internal Grant Agency of TBU in Zlin [IGA/CPS/2023/002