rss_2.0Industrial Chemistry FeedSciendo RSS Feed for Industrial Chemistry Chemistry Feed potential of lactic acid bacteria<abstract><title style='display:none'>Abstract</title><p>Acidification in lactic-fermented foods is realized by lactic acid bacteria as an added starter culture or by autochthonous strains. These microbial strains possess different prominent features that define the technological, organoleptic, nutritional, and microbial safety aspects of the product. The bioprotective effect of the bacterial strains may be related to antagonistic properties against food spoilage and/or pathogenic strains. The aim of the present study is to determine the antimicrobial properties of three different food-grade lactic acid bacteria in order to use them as bioprotective cultures. Our findings show that the <italic>Lactobacillus pentosus</italic>, <italic>Enterococcus faecalis</italic>, and <italic>Pediococcus parvulus</italic> exerted a bacteriostatic effect on <italic>Escherichia coli</italic> and <italic>Bacillus cereus</italic>, whereas the <italic>Saccharomyces cerevisiae</italic> growth was not inhibited, which made them susceptible agent for co-culture systems.</p></abstract>ARTICLE2020-11-05T00:00:00.000+00:00Antibacterial activity of plant extracts against isolated from ready-to-eat salads<abstract><title style='display:none'>Abstract</title><p>Ready-to-eat salads are becoming more and more popular. However, due to their ingredients, they represent a suitable growth environment for different microbes. In the prevention of foodborne diseases, hygienic food preparation and appropriate storage conditions are very important. During this study, ten different ready-to-eat salads were analysed for the presence of <italic>Listeria monocytogenes</italic>. Five different selective agar mediums were used for the enumeration and isolation of <italic>Listeria monocytogenes</italic>. The isolated bacterial strains were subjected to morphological and biochemical confirmation tests. The antibacterial effects of five different freshly squeezed vegetable juices (carrots, celery, beets, horseradish, and onions) and of five essential oils (dill, thyme, oregano, lemongrass, and sage) were determined against <italic>Listeria monocytogenes</italic>, <italic>Listeria innocua</italic>, and <italic>L. monocytogenes</italic> strains isolated from ready-to-eat salads. Based on the results obtained from fresh vegetable juices, carrot juice exerted the highest antibacterial effect, while the others showed no or slight inhibitory effect (horseradish, beets, onions) against <italic>Listeria</italic> species. Among the essential oils, thyme, lemongrass, and oregano showed the strongest antibacterial effect against the studied <italic>Listeria</italic> species.</p></abstract>ARTICLE2020-11-05T00:00:00.000+00:00Functional and pasting characteristics of and analogues from cassava () and breadfruit () blends<abstract><title style='display:none'>Abstract</title><p><italic>Pupuru</italic> and <italic>pupuru</italic> analogues are fermented, smoked food products usually produced from cassava or cassava substituted with a varying ratio of breadfruit. This study aims at determining and comparing the functional and pasting characteristics of <italic>pupuru</italic> and <italic>pupuru</italic> analogues with a view to expanding the utilization of breadfruit as <italic>pupuru</italic> analogue. The functional properties (water absorption capacity (%), swelling power (g/g), solubility (%)) and pasting characteristics were determined using standard methods. The results showed that the yield of the products ranged between 24.66 and 29.65%, and it was not affected by the amount of breadfruit substituted. The water absorption capacities of the <italic>pupuru</italic> and <italic>pupuru</italic> analogues ranged between 216.0 and 449.0%; this parameter increased with temperature increase. Both swelling power and solubility had a rapid increase from 80 °C to 90 °C. Pasting temperature ranged between 73.15 and 83.66 °C, with peak time between 4.58 and 5.33 min. The final viscosity ranged between 94.08 and 391.83 RVU, and it decreased with increase in breadfruit substitution. The study concluded that adding breadfruit to cassava in <italic>pupuru</italic> analogue production improved some of the functional and pasting properties of the product.</p></abstract>ARTICLE2020-11-05T00:00:00.000+00:00Biotic and abiotic risks of soil biochar treatment for food safety and human health<abstract><title style='display:none'>Abstract</title><p>Pyrolysis technology facilitates the heating of organic waste biomass in a very low oxygen environment to temperatures over 400 °C. The high carbon content and surface area of the char produced via slow pyrolysis makes it suitable for a range of purposes that would sequester the carbon it contains. For example, there is a growing interest in its use as a soil amendment, which enhances plant growth and nutrient use efficiency.</p></abstract>ARTICLE2020-11-05T00:00:00.000+00:00Characterization of some bottled Romanian mineral waters on the basis of the total mineral content<abstract><title style='display:none'>Abstract</title><p>Romania has many mineral water sources due to its geological features. In the present study, bottles of 26 Romanian mineral water brands were purchased from the market to make a characterization based on the pH, conductivity, and fixed residue content. Focusing on the total fixed residue, the distribution of low, medium, and highly mineralized water was 43.9%, 41.46%, and 14.63% respectively. The mean of fixed residue concentration was 763.3 mg/L, ranging from 40.37 mg/L to 2,603 mg/L. The pH values of the still mineral waters varied between 6.86 and 7.91, while the pH values of the sparkling mineral waters were the lowest (4.7). The conductivity was strongly related to the concentration of the ions, so the maximum measured conductivity for the still waters was 573 <italic>μ</italic>S/cm, for the partially sparkling waters 2,133 <italic>μ</italic>S/cm, and for the sparkling mineral waters 3,079 <italic>μ</italic>S/cm. The chemical composition of the mineral waters was highly dependent on the rock types. Using the hierarchical cluster analysis, two different clusters were detected according to the main characteristics of mineral waters.</p></abstract>ARTICLE2020-11-05T00:00:00.000+00:00The aflatoxin content of milk and dairy products as well as breast milk and the possibilities of detoxification<abstract><title style='display:none'>Abstract</title><p>Aflatoxins are fungal toxins produced by <italic>Aspergillus</italic> species, which, due to increasing temperature and climate change in the temperate zone, appeared in the most important feeding plant and food ingredients. The most toxic of them is aflatoxin B1 (AFB1), which hydroxylates to aflatoxin M1 in the body of dairy animals and humans, and excretes in the milk. With the development of analytical methods, researchers are now able to detect toxins with a concentration of ng/kg. It was found that in most countries in Europe both breast milk and cow’s milk may contain AFM1, and therefore increased attention should be paid to the toxin content of milk, and that those above the limit should be excluded from consumption. In addition to cow’s milk, the AFM1 toxin content of breast milk can also be significant, the precursors of which are introduced into the mother’s body with food. Aflatoxins are highly resistant to physical, chemical, and microbiological effects, so the detoxification of foods, especially milk, is almost impossible. The best solution appears to be feeding the animals with toxin-free feeds or feeds containing toxins below the permitted limit, without giving opportunity to the toxins to enter the milk from the feed and from there into the human body.</p></abstract>ARTICLE2020-11-05T00:00:00.000+00:00Physico-chemical and sensory properties of and analogues from co-fermented cassava () and breadfruit () blends<abstract><title style='display:none'>Abstract</title><p>The physico-chemical and sensory qualities of <italic>pupuru</italic> analogues produced from co-fermented cassava and breadfruit blends were investigated. Cassava and breadfruit were processed separately and cofermented at different proportions to produce <italic>pupuru</italic> and <italic>pupuru</italic> analogues. Seven different samples were produced with the ratios of 100:0, 90:10, 80:20, 50:50, 20:80, 10:90, and 0:100 cassava:breadfruit respectively. The proximate composition, bulk density, hydrogen cyanide, pH, TTA, and sensory properties of the sample were determined using standard methods. The results showed that the protein (2.86–6.41%), fat (0.43–2.05%), ash (0.36–1.17%), crude fibre (0.68–2.83%), and energy values (393.84 to 399.38 kcal/100 g) increased together with breadfruit substitution. The bulk density, pH, total titratable acidity, and hydrogen cyanide content of the sample was in the ranges of 0.47–0.60 g/ml, 4.30–5.30, 0.18–0.31%, and 0.56–1.68 mg/100 g respectively. The <italic>pupuru</italic> analogues had lower hydrogen cyanide content than <italic>pupuru</italic>. The <italic>pupuru</italic> analogues up to 50% breadfruit substitutions had acceptable sensory attributes, comparable to <italic>pupuru</italic>. The study concluded that <italic>pupuru</italic> analogues of acceptable quality can be produced from co-fermented cassava and breadfruit; this entails increasing the utilization of breadfruit.</p></abstract>ARTICLE2020-11-05T00:00:00.000+00:00Impact of refrigerated storage on the bioactive compounds and antioxidant capacity of two Algerian carrot varieties ( L.)<abstract><title style='display:none'>Abstract</title><p>Carrot (<italic>Daucus carota</italic> L.) is one of the main root vegetables rich in bioactive compounds with appreciable health-promoting properties, largely consumed in Algeria. In the current study, the storage effect (at 4 °C throughout 12 days) on bioactive compound stability and the antioxidant activity of two Algerian orange carrot varieties (Supermuscade and Touchon) were investigated. Total phenolic content of samples was determined by the Folin–Ciocâlteu method. Antioxidant capacity was determined spectrophotometrically, based on the evaluation of Free Radical Scavenging Activity (FRSA) using DPPH radical and Ferric Reducing Power (FRP). The results showed that the Touchon variety is richer in phenolics, flavonoids, and carotenoids and presents higher antioxidant activity in comparison with the Supermuscade variety. At the end of storage, the bioactive compound content and antiradical activity increased significantly (p &lt; 0.05). Also, an extremely significant correlation (p &lt; 0.001) was observed between the antioxidant contents and the antioxidant capacities of aqueous carrot extracts.</p></abstract>ARTICLE2020-11-05T00:00:00.000+00:00Improved rack and pinion drive<abstract> <title style='display:none'>Abstract</title> <p>A typical rack and pinion drive set is comprised of a rack and a pinion. There is an inter-tooth clearance between the mating teeth of the rack and the pinion, which has advantages and disadvantages. The disadvantage of this clearance is the errors that occur in the positioning of the machine tool during set-up. Elimination of clearance between teeth is possible by using a pinion drive with two pinions. This ensures continuous contact between the teeth, regardless of the direction of machine movement.</p> <p>These are found on new machines, while older machines do not have such a solution. This paper presents a solution with two pinions, which can be used in such older machines and which makes it possible to achieve qualitative parameters that were not possible before.</p> </abstract>ARTICLE2021-09-04T00:00:00.000+00:00Rzeszów as an example of a ‘new town’ tailored for the modern era<abstract> <title style='display:none'>Abstract</title> <p>The city life cycle is an issue that can be considered from many perspectives. Klaassen’s period cycle is the basic model of city life: urbanisation– suburbanisation–deurbanisation–reurbanisation. In each of these periods, cities develop by, building and transforming their structures. This article presents various approaches to shaping new urban spaces using the city of Rzeszów as an example. In the city’s history, three periods are distinguished during which structures referred to as the ‘new town’ were created in the 16<sup>th</sup> and 20<sup>th</sup> centuries and continue to be created now. After analysing the site-forming processes, the most important features of new-town urban systems are compared.</p> </abstract>ARTICLE2021-04-22T00:00:00.000+00:00The formation of zinc coatings in nanocrystallised zinc powders<abstract> <title style='display:none'>Abstract</title> <p>The kinetics of and mechanism for galvanising low-carbon steel (0.2% C) were examined in powder media which were pre-treated to obtain a fine nanostructured ZnO layer on the surface of zinc powder particles. The effective diffusion coefficient of Zn atoms through the ZnO shell was estimated to be in the order of 1·10<sup>−10</sup> m<sup>2</sup>·s<sup>−1</sup>. The contribution of the Zn-gas evaporation/condensation microprocesses, which could occur in relation to the above diffusion through a nanostructured surface layer, was evaluated with numerical calculations in the temperature range of 550–950 K and for an average particle size of ZnO up to 100 nm. Our results suggest that the outward diffusion of metallic zinc takes place from the core of powder microparticles across the nano-grain boundaries of their modified surface layer, and can be further intensified by the presence of other inter-phase defects, such as nano-porosity.</p> </abstract>ARTICLE2021-07-12T00:00:00.000+00:00The application of topological data analysis to human motion recognition<abstract> <title style='display:none'>Abstract</title> <p>Human motion analysis is a very important research topic in the field of computer vision, as evidenced by a wide range of applications such as video surveillance, medical assistance and virtual reality. Human motion analysis concerns the detection, tracking and recognition of human activities and behaviours. The development of low-cost range sensors enables the precise 3D tracking of body position. The aim of this paper is to present and evaluate a novel method based on topological data analysis (TDA) for motion capture (kinematic) processing and human action recognition. In contrast to existing methods of this type, we characterise human actions in terms of topological features. The recognition process is based on topological persistence which is stable to perturbations. The advantages of TDA are noise resistance and the ability to extract global structure from local information. The method we proposed in this paper deals very effectively with the task of human action recognition, even on the difficult classes of motion found in karate techniques. In order to evaluate our solution, we have performed three-fold cross-validation on a data set containing 360 recordings across twelve motion classes. The classification process does not require the use of machine learning and dynamical systems theory. The proposed classifier achieves a total recognition rate of 0.975 and outperforms the state-of-theart methods (Hachaj, 2019) that use support vector machines and principal component analysis-based feature generation.</p> </abstract>ARTICLE2021-08-18T00:00:00.000+00:00The influence of water price and the number of residents on the economic efficiency of water recovery from grey water<abstract> <title style='display:none'>Abstract</title> <p>This article presents the results of an analysis of the economic viability of using an installation for the treatment of grey water. Economic indicators in the form of simple payback time (SPBT) and net present value (NPV) were used in the analysis. The use of a dual water supply system should theoretically enable the reduction of the costs of both water supply and sewage disposal, ensuring investment profitability. The article presents the impact of the number of residents as well as the impact of water and sewage on the profitability of using example water-recovery systems. It was found that both factors have a huge impact on the result of the economic analysis. For a small number of residents and at a low price of water supply and sewage disposal, it is not profitable to invest in a water-recovery system. This is due to the high price of purification devices.</p> </abstract>ARTICLE2021-02-05T00:00:00.000+00:00Analysis of the possibility of employing 3D printing technology in crisis situations<abstract> <title style='display:none'>Abstract</title> <p>Events related to climate change and the increase in the occurrence of natural disasters, as well as the increasing incidence of new diseases, have all caused the prominence of regional security and crisis management around the world to rise. Three-dimensional printing, which has seen noteworthy developed in recent years, both in terms of print parameters, and the magnitude of the production potential, may prove helpful in this matter. Enormous opportunities have arisen which, if properly directed, can save human life and preserve health in crisis situations, when traditional supply chains could be disrupted or even prevented. The use of additive technologies, however, has its limitations and in order to be able to take full advantage of the opportunities they offer, a legitimate functional system should be created and embedded within proper structures to support crisis management. This paper presents the advantages and disadvantages of using 3D printers and the possibility of their implementation as part of the current crisis-response systems. The article proposes a model for incorporating additive technologies into the crisis-management system.</p> </abstract>ARTICLE2021-06-20T00:00:00.000+00:00A suitability assessment using an instrumented impact test of the use of selected structural steel grades on the basis of their changes in response to exposure to fire<abstract> <title style='display:none'>Abstract</title> <p>In this article, changes occurring in structural steel after exposure to fire are described and discussed. The steel structure before and after fire determines its susceptibility to brittle cracking. The individual phases of cracking are described and interpreted on the basis of a load-displacement graph, directly obtained from the Charpy impact test. The relationship between the intensity of individual fracture energies and the type and appearance of the sample fractures are demonstrated. The program of planned Charpy impact tests and expected hazards after the exposure to fire of selected steel grades are presented. Standard simplified load-displacement graphs are assigned to the steel transition curve. The course of various cracking mechanisms occurring in the case of brittle fractures and plastic fractures are discussed. The aim of this article is to evaluate the possibility of the assessment of structural steel after a fire based on results obtained during the Charpy impact test.</p> </abstract>ARTICLE2021-04-27T00:00:00.000+00:00Humic substances and significance of their application – a review<abstract> <title style='display:none'>Abstract</title> <p>This paper is based on recent articles regarding applications of humic substances (HSs). HSs are natural organic materials, which have a number of potential applications. Furthermore, HSs are cheap, widespread and obtainable from bio-waste materials. HSs can be used as organic compound sorbents or in detoxification. They are applied as organic additives due to their positive effect on soil and plants, even under stress conditions. HSs reduce water consumption and minimise environmental problems. HSs are utilised for the remediation of multi-metal contaminated soils and as substitutes for synthetic washing agents. From an environmental engineering point of view, it is beneficial to remove HSs from municipal management, where they are undesirable (by-products of disinfection) and to utilise them where they are valuable. The aim of this article is to provide a greater insight into research about the applications of HSs.</p> </abstract>ARTICLE2021-08-18T00:00:00.000+00:00A review of modern materials used in military camouflage within the radar frequency range<abstract> <title style='display:none'>Abstract</title> <p>The article presents an overview of materials which can be employed used to camouflage objects on the modern battlefield in the radar frequency range.</p> </abstract>ARTICLE2021-02-10T00:00:00.000+00:00Mixing effects in the river downstream from pollution discharge point<abstract> <title style='display:none'>Abstract</title> <p>This paper follows the propagation of pollution in a river with a rectangular cross-section of the river bed and a variable cross-sectional velocity. The calculations were made for steady flows and steady pollutant concentrations. To approximate the velocity distribution in the river bed a set of equations for current and vorticity functions was solved. The distribution of pollutant concentrations in the river was calculated from a bidirectional advection and turbulent diffusion equation. Analysis of the distribution of concentrations leads to the conclusion that the effects of transverse advection associated with a lateral inflow of pollutants disappear relatively quickly. Therefore, the distribution of concentrations in cross sections further downstream from the point of pollutant discharge can be determined quite accurately just from an advection-diffusion model, with no transverse advection effects included. Such a level of accuracy is usually sufficient to assess the impact of a pollution source on the aquatic environment. The transverse mixing of pollutants in the stream proceeds slowly and creates a large mixing zone in which the concentrations of pollutants (low but still significant for water quality) can be detected in cross-sections that are remote from the pollutant discharge point. Transverse advection may be ignored while calculating concentrations in remote cross sections at straight watercourse sections and in steady state conditions.</p> </abstract>ARTICLE2021-04-18T00:00:00.000+00:00Small Historical Centres: an opportunity for the “smart” revitalization of Inner Areas in the Post (post) COVID Era<abstract> <title style='display:none'>Abstract</title> <p>The Pandemic is forcing everyone to become aware of the need for a change in the cultural and socio-economic paradigms of recent decades.</p> <p>During the twentieth century, on the one hand, entire populations concentrated in urban areas with ever higher population densities, at the same time giving rise to the phenomenon of “urban sprawl” or “suburbanization”.</p> <p>On the other hand, entire territories have been abandoned (the so-called “inner areas”).</p> <p>Now, we can define territorial rebalancing strategies based precisely on the reactivation of “inner areas”. Strategies that, in the Post (post) COVID era will have to be not only resilient, but anti-fragile. And the key is precisely in the future of the smaller historical centres.</p> <p>This article aims to review the strengths and weaknesses of small historic centres, outlining possible scenarios for their “smart” revitalization and for a true sustainable and inclusive development.</p> </abstract>ARTICLE2021-04-18T00:00:00.000+00:00The new function of architectural monuments – a comparative analysis of two different cases: Palazzo Querini Stampalia and the Fondaco dei Tedeschi building<abstract> <title style='display:none'>Abstract</title> <p>This paper discusses the long-term vision of the historic city development, where buildings assume a new function over time. The discussion is based on the example of Palazzo Querini Stampalia and Fondaco dei Tedeschi – two monuments restored to Venice in a new, different role. In the comparative analysis of the transformation of the buildings, particular attention was paid to the cultural, social and economic context of the city. This article aims to review the strengths and weaknesses of the new-use scenarios, outlining the renovation of the monuments and its added value for cities. The author concluded that no matter what the new function of the building is, it is worth renovating them, because this way the heritage can survive and this should be the central objective of a long-term vision.</p> </abstract>ARTICLE2021-09-10T00:00:00.000+00:00en-us-1