70 research outputs found

    An insight into curcumin-based photosensitization as a promising and green food preservation technology

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    Consumer awareness on the side effects of chemical preservatives has increased the demand for natural preservation technologies. An efficient and sustainable alternative to current conventional preservation techniques should guarantee food safety and retain its quality with minimal side effects. Photosensitization, utilizing light and a natural photosensitizer, has been postulated as a viable and green alternative to the current conventional preservation techniques. The potential of curcumin as a natural photosensitizer is reviewed in this paper as a practical guide to develop a safe and effective decontamination tool for industrial use. The fundamentals of the photosensitization mechanism are discussed, with the main emphasis on the natural photosensitizer, curcumin, and its application to inactivate microorganisms as well as to enhance the shelf life of foods. Photosensitization has shown promising results in inactivating a wide spectrum of microorganisms with no reported microbial resistance due to its particular lethal mode of targeting nucleic acids. Curcumin as a natural photosensitizer has recently been investigated and demonstrated efficacy in decontamination and delaying spoilage. Moreover, studies have shown the beneficial impact of an appropriate encapsulation technique to enhance the cellular uptake of photosensitizers, and therefore, the phototoxicity. Further studies relating to improved delivery of natural photosensitizers with inherent poor solubility should be conducted. Also, detailed studies on various food products are warranted to better understand the impact of encapsulation on curcumin photophysical properties, photo-driven release mechanism, and nutritional and organoleptic properties of treated foods

    Polymer application for separation/filtration of biological active compounds

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    AbstractMembrane technology is an important part of the engineer’s toolbox. This is especially true for industries that process food and other products with their primary source from nature. This review is focused on ongoing development work using membrane technologies for concentration and separation of biologically active compounds, such as polyphenols and flavonoids. We provide the readers not only with the last results achieve in this field but also, we deliver detailed information about the membrane types and polymers used for their preparation.</jats:p

    Biogenic amines in their role in living systems

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    Although polyamines (PA) belong to relatively simple aliphatic substances, their role in life processes of animals and plants is of key importance [1–5]. The group of the most important amines, called biogenic ones includes: Spermine (Spm): H2N(CH2)3NH(CH2)4NH(CH2)3NH2 Spermidine (Spd): H2N(CH2)3NH(CH2)4NH2 Putrescine (Put): H2N(CH2)4NH2. Of secondary importance are homologues of biogenic amines, occurring in lower contents in living organisms [2, 6–8]: 1,3-diaminopropan: H2N(CH2)3NH2 Cadaverine: H2N(CH2)5NH2 Homospermidine: H2N(CH2)4NH(CH2)4NH2 Norspermine (3,3,3-tet): H2N(CH2)3NH(CH2)3NH(CH2)3NH2 Thermospermine: H2N(CH2)3NH(CH2)4NH(CH2)4NH2 Caldopentamine: H2N(CH2)3NH(CH2)3NH(CH2)3NH(CH2)3NH2. The first polyamine discovered in a living organism was tetramine, a spermine crystallised out of sperm in 1678 by Van Leewenkeuk [9]. Putrescine was discovered in the end of the 19th century in microbes and then triamine: spermidine was discovered in the beginning of the 20th century [2]. Later studies have shown that in animal cells spermidine and spermine occur at elevated levels, while in prokaryotes spermidine and putrescine contents are dominant. Putrescine, spermidine, 1,3-diaminopropan, homospermidine, norspermidine, and norspermine have been found in many gramnegative bacteria and algae [7, 10, 11]. Total concentration of PA in living organisms is on the order of millimols, however, the concentration of free polyamines is much lower. A low level of free amines follows from the fact that they are involved in noncovalent interactions with biomolecules occurring in living organisms such as nucleic acids, proteins, or phospholipids. High concentrations of non-bonded polyamines have been detected first of all in young molecules in the process of growth, in particular in rapidly proliferating cancer cells [6, 12]. Elevated levels of free polyamines have been observed, e.g. in breast, colon, lung, prostate, and skin tumours, accompanied by changed levels of enzymes responsible for biosynthesis and catabolism of polyamines. Because of the increased level of free polyamines and a tendency of their interaction with nucleic acids and other bioligands, these compounds have become objects of intense study [1, 13–19]. There is no doubt that the regulation of biosynthesis of polyamines and catabolism is one of the most important pathways in the search strategy for chemoprevention and chemotherapeutic drugs [14, 15, 20–36]. The present state of knowledge of these processes, their significance in biological systems, and their application in medicine are presented in subsequent sections of this chapter

    Effect of acorn size and sowing depth on Quercus robur and Q. petraea seedling emergence and height

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    The aim of investigations was to establish the effect of sowing depth in the nursery on seedling quality and emergence, depending on weight of Quercus robur and Q. petraea acorns. Carried out researches had a preliminary character because seeds were collected separately only from 5 trees. We found no significant effect on seedling quality and emergence for Q. robur with the largest weight of acorns (mass of 1000 seeds equaling 6660 g) sown at the depth of 9 cm. Such relations had not occurred in Q. petraea. Sowing at the depth of 3−9 cm in the nursery had no significant effect on seedling height within each investigated seed lot. At the greater sowing depths, the dry weight of seedling roots was lower, while dry weight of shoots was higher

    Metals in Wastes

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    Metals in Wastes is an excellent guide for scientists, students, engineers, chemists, and industrial chemists who are looking for knowledge of the main sources of metals in industrial wastes. Metals are valuable materials that can be recycled again and again without degrading their properties. The recycling of metals enables us to preserve natural resources while requiring less energy to process than the manufacture of new products using virgin raw materials. A team of experts reviews the state-of-the-art and provides the readers not only with a comprehensive in-depth overview of the main composition of wastes but also discloses innovative methods which have been applied for recovery of critical and valuable metals in petrochemical industry, rubber, energy and automotive industries. This know-how could be considered as a useful reference tool for moving towards the zero-waste economy. Additionally, the book describes the economic aspects of metals recovery from various sources. This is essential for those alr"Металлы в отходах" - отличное руководство для ученых, студентов, инженеров, химиков и специалистов по промышленной химии, которые ищут знания об основных источниках металлов в промышленных отходах. Металлы - это ценные материалы, которые можно перерабатывать снова и снова, не ухудшая их свойств. Переработка металлов позволяет нам сохранять природные ресурсы, требуя при этом меньше энергии для переработки, чем при производстве новых продуктов из первичного сырья. Команда экспертов проводит обзор современного состояния и предоставляет читателям не только всесторонний углубленный обзор основного состава отходов, но и раскрывает инновационные методы, которые были применены для извлечения важнейших и ценных металлов в нефтехимической, резиновой, энергетической и автомобильной промышленности. Это ноу-хау можно было бы рассматривать как полезный справочный инструмент для перехода к экономике с нулевыми отходами. Кроме того, в книге описаны экономические аспекты извлечения металлов из различных источников. Это важноИспользуемые программы Adobe Acroba

    Photo-triggered release in polyamide nanosized capsules

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    In this work, nanosized capsules based on a lightly cross-linked polyamide containing azobenzene moieties in the main chain were synthesized by miniemulsion interfacial polymerization. The obtained nanocapsules were loaded either with toluene or with the fluorescent probe coumarin-6 as a core. Diameters of the nanocapsules were in the 100-900 nm range, depending on the selected emulsion conditions. The morphology and shape of the samples were observed by TEM and SEM while the emulsion droplets and nanocapsules size was measured by DLS. Under continuous UV irradiation the polymer underwent E-Z photoisomerization allowing the release of the encapsulated material. Variation in diameter of the nanocapsules with the time of UV irradiation was detected through DLS analysis. 10-30% growth was observed, depending on the sample. The kinetics of release of coumarin-6 was followed by spectrofluorimetry in ethanol. In absence of irradiation, the fluorescence intensity appeared to be constant over time, while it increased when the sample was irradiated with 360 nm UV light
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