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According to the long-term plan accepted by the Editorial Board, in the first days of July 2018 we present to our readers the 56th issue of the Polish Journal of Commodity Science. Continuing the efforts to widen the group of our readers all the papers are published in English. We would like to remind that now, only papers written in English are accepted by the editors. As before, each paper contains a wide summary in Polish and English. The summaries in both language versions of all the works published one can find on our web page Moreover, at the web page an open-access to all the papers published up to 2017 is offered. A series of 12 articles in the current issue of our magazine is opened by the work of Banach, Smoczyński and Żywica regarding the qualitative and environmental implications of conventional and organic food. The work discusses the essence of organic farming as well as specific rules and ways of obtaining food designated as organic. The authors indicate that the parameters characterizing the nutritional value of foods of vegetable origin are usually more favorable for organic products compared to foods produced by conventional methods. Attention is also drawn to the content of foreign chemical compounds that determine the health value of organic food, which according to the authors is usually lower than for conventional food. The object of the work of Lisińska-Kuśnierz and Kabaj is the usefulness and informability of the packaging of bag-in-box not from concentrate juices (NFC). The aim of the researchwas to determine the preferences of consumers and their opinions on the use of juices in bag-inbox packaging, as well as consumer and expert assessment of the packaging of selected apple juices. The research applied a modified TVScore method, which enabled the evaluation of the packaging in terms of visibility, legibility, understanding of obligatory marking and assessment of pictograms informing about the way of using the bag-in-box packaging. It was found that none of the apple juice packaging tested met the expectations of consumers fully, which indicated the need for research on new and modified bag-in-box packaging designs. Juice quality is the subject of research by Suwała and Halagarda. The authors discuss the results of their tests on the quality of pear juices in terms of absolute quality requirements agreed with the industry, as well as their authenticity and identity. On the basis of physicochemical and organoleptic tests of pear juices, no significant differences between the two groups of direct pear juices investigated were observed. It was found that the tested pear juices were characterized by a similar degree of non-compliance with the guidelines of the Code of Practice regarding the criteria of assessing their authenticity and identity. The subject of the research presented in the two subsequent papers is the quality of coffee. In the first of these, Turek presents the results of research on the role of the brand in assessing the quality of coffee. Based on the results of sensory tests regarding the quality of instant coffee and comparison of the results obtained with the results of studies on the preferences of selected coffee brands, the is trying to answer the question whether there is a compatibility in the perception of the tested coffee brand and the sensory evaluation carried out using a blind test. The results obtained by the author indicate that there is no significant compatibility of the idea of the quality of the coffee on the basis of its brand knowledge and the results of the sensory evaluation.
 In the second article, Dmowski, Śmiechowska and Pawłowska present the results  of their  research on the authenticity of selected coffees available in Tri-City. The aim of the study was to examine the authenticity of selected coffee beans on the basis of visual assessment of grains and in the case of roasted coffees - on caffeine content. There were numerous cases of lack of information that the product was a mixture of several types of coffee. In addition, it was found that the caffeine content could be employed in the process of testing the authenticity of coffee. In the paper by Bińczak and Zmudzinski research on the safety of tea drinks prepared with the addition of lemon juice was discussed. Citric acid introduced into tea contributes to the extraction of aluminum ions in the form of water-soluble and easily digestible aluminum citrate, which accumulates in tissues and thus, can cause many changes (mainly in the nervous system) including Parkinson's and Alzheimer's diseases. The paper presents the results of research on the effect of the presence of citric acid on the ability to extract aluminum from tea leaves. The maximal increase of extracted aluminum from tea as a result of the addition of citric acid was found in the case of red tea, while minimal - for green tea. In the next article, Kaczmarek and Zieliński present the results of research on the effect of the solvent composition used in the extraction of dried marjoram (Oreganum vulgare) on the antiradical activity of extracts with potential applications in cosmetic products. The work is a record of the results of the research on the duration of extraction of dried marjoram in wateralcoholic systems and on the effect of the composition of extractants applied on the values of qualitative determinants characterizing the antiradical activity of extracts obtained. It was found that in the tested systems containing aqueous solutions of ethyl alcohol, mixtures containing about 50% ethanol proved to be more effective extractants than single solvents. Halagarda and Miśniakiewicz present the results of research on the nutritional value and sensory quality of commercial rye bread and wheat-rye bread produced using traditional methods. Comparing the nutritional value of conventional bread and bakery products made by traditional methods, no significant differences were found, although the traditional mixed bread contained less salt. There were some differences in the calorific value as well as water and carbohydrate content between both types of bread. In the next paper, Pukszta, Ocieczek and Korpowska present the results of research on changes in the content of carotenoid pigments in red bell peppers depending on the duration of freezing storage and the method of thawing used. A significant influence of freezing storage duration and thawing method on the content of carotenoids in red bell peppers stored in a frozen state was demonstrated. It was found that thawing peppers at 5°C allowed to keep a higher content of carotenoid pigments than thawing at 20°C. Biofilms composed of a system of many species of microorganisms that show increased, as compared to planktonic cells, resistance to commonly used antimicrobial substances are a threat to maintaining the cleanliness of production lines during production processes. The research performed by Marchwińska, Gwiazdowska and Juś was aimed at the determination of the possibility of maintaining the microbiological safety of production lines. Antibiotic activity of commercial aqueous solutions containing nanocopper, nanosilver and nanogold particles was studied. The antibiophilic activity of the tested solutions was diverse, depending on the strain type, bacterial cell concentration, type and concentration of nanoparticles. The highest antibiophilicity was confirmed for solutions containing nanosilver particles. In the consecutive article Wolak and Zając present the results of the second part of engine oil operation tests. The authors determined changes in the dynamic viscosity of engine oils occurring during the operation of combustion engines. It was found that the results obtained could be helpful in making rational decisions regarding the service life of engine oils.
 In the last work, Popek presents the problems of sea transport from the point of view of its impact on the increase of air and water pollution. The aim of the work was to analyze the possibilities of providing ships with energy from renewable sources. The author states that sea transport has a significant impact on air quality through the emission of greenhouse gases (GHG) and particulate matter (PM) from exhaust gases, which can have serious consequences for human health and life expectancy, as well as for terrestrial and marine ecosystems. The paper discusses the possibilities of using biofuels, liquefied natural gas, methanol as well as solar and nuclear energy as an alternative fuel in sea transport. The 56th issue of the quarterly is closed by the columnt „PJCS Announcements”. One can find there a text on the achievements of prof. dr hab. inż. Jerzy Żuchowski from the University of Technology and Humanities in Radom on the occasion of the 50th jubilee of Professor's research work.
I wish you a nice reading
 PJCS Editor  Prof. dr hab. inż. Ryszard Zieliński




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