1,721,041 research outputs found
Polymers and Food Packaging: A Short Overview
No full textA discussion on the state-of-the-art performance of biopolymers and functional biopolymers, focusing on food packaging applications, is presented in this chapter. An overview is given of the most important materials used for producing biobased films, their limitations, recycling pattern, and solutions thereof. Furthermore, transport phenomena and regulation concerns are extensively treated
Functional Polymers for Food Processing
No full textPolymeric materials can be used as functional elements for reaching an efficient food production and processing, with considerable advantages for the whole food industry. Among others, the applicability of polymers involves their use in agriculture, animal feed, modification of food rheology, and the development of functional food and nutraceutics
Post-Quantum Attribute-Based Encryption: Performance Evaluation and Improvement for Embedded Systems
No full textCiphertext-Policy Attribute-Based Encryption (CP-ABE) is an encryption paradigm that embeds access control func-tionalities within ciphertexts. It has shown to be useful for protecting privacy and intellectual property in embedded systems, especially when confidential data is temporarily stored on untrusted cloud or edge servers. However, current CP-ABE ciphers are generally based on pairing mathematics, which is broken if attacked by large-scale quantum computers. Thus, these ciphers will not be secure anymore in the future. In this paper, we focus on a RLWE-based CP-ABE cipher (namely the scheme proposed by Gür et al. in 2019 on IEEE Trans. on Computers), which is believed to be resistant to quantum attacks, so it is a candidate replacement of pairing-based ABE schemes in the future quantum world. Specifically, we measure its performance in terms of processing time and memory with reference to two embedded applications: smart home privacy and automotive FOTA intellectual property protection. We also propose a method to improve the encryption efficiency by dividing it into a slow offline phase and a fast online phase
Functional Polymers in Food Science: From Technology to Biology
No full textPolymers are an important part in everyday life; products made from polymers range from sophisticated articles, such as biomaterials, to aerospace materials. One of the reasons for the great popularity exhibited by polymers is their ease of processing. Polymer properties can be tailored to meet specific needs by varying the "atomic composition" of the repeat structure, by varying molecular weight and by the incorporation (via covalent and non-covalent interactions) of an enormous range of compounds to impart specific activities. In food science, the use of polymeric materials is widely explored, from both an engineering and a nutraceutical point of view. Regarding the engineering application, researchers have discovered the most suitable materials for intelligent packaging which preserves the food quality and prolongs the shelf-life of the products. Furthermore, in agriculture, specific functionalized polymers are used to increase the efficiency of treatments and reduce the environmental pollution. In the nutraceutical field, because consumers are increasingly conscious of the relationship between diet and health, the consumption of high quality foods has been growing continuously. Different compounds (e.g. high quality proteins, lipids and polysaccharides) are well known to contribute to the enhancement of human health by different mechanisms, reducing the risk of cardiovascular disease, coronary disease, and hypertension. This first volume, of this two volume book, concerns the application of polymers in food packaging
Antioxidant Polymers by Free Radical Grafting on Natural Polymers
No full textThis chapter presents an overview of the different antioxidant polymeric materials, based on natural macromolecules, which can be obtained by employing the free radical grafting procedure. Free radical grafting is a straightforward method which allows the covalent insertion of the antioxidant molecules onto the polymer backbone without the use of organic solvents or toxic radical initiators. Chitosan, starch, inulin and alginate are examples of polysaccharides widely used to obtain these kind of systems, while some gelatin-antioxidant materials will also be presented as representative examples of protein-based conjugates. The advantages to having these systems consist of their high stability, biocompatibility and good biological properties. All these characteristics make them suitable systems for several pharmaceutical and food applications, such as delivery devices of drugs, as preservatives and for food packaging
Multi-responsive hydrogels as biomedical devices
No full textPharmaceutical and biomedical application of hydrophilic materials has emerged as one of the most signifi cant
trends in the area of nanotechnology. “Intelligent” polymeric devices able to undergo morphological
modifi cations in response to an internal or external stimulus, such as pH, redox balance, temperature,
magnetic fi eld, and light have been actively pursued. In an effort to further improve the performances of the
biomedical device, novel dual and multistimuli-responsive hydrogels responding to a combination of two or
more signals have recently been developed by incorporating different stimulus-responsive elements into a
network via polymerization processes. Notably, these combined responses take place either simultaneously
at the pathological site, or sequentially from hydrogel preparation, hydrogel transporting pathways, to
cellular compartments. These dual and multistimuli-responsive polymeric materials lead to superior in
vitro and/or in vivo therapeutic effi cacy, with programmed site-specifi c feature and remarkable potential for
targeted therapy. This entry highlights the recent developments in the synthesis of dual and multistimuliresponsive
hydrogels for applications in the biomedical and pharmaceutical fi elds, with a particular focus on
the correlation between the hydrogel physical feature and the precision situ-controlled delivery of bioactive
compounds
Recent development in the synthesis of eco-friendly polymeric antioxidants
No full textThe growing impact of environmental concerns of industrial processes carried out to the development of the socalled “Green Chemistry” approaches. By these technologies, the use of any hazardous substances within the synthesis of chemicals, nutraceuticals or therapeutics, is avoided, and considerable safety and biocompatibility advantages are raised.Among the different products prepared by Green Chemistry, high molecular weight antioxidants show remarkable appeal within the scientific community by virtue of their advantageous chemical and biological properties. These functional materials have been prepared by different synthetic strategies, classified in condensation methods, radical grafting and enzymatic catalysis. This review summarizes the chemical mechanisms of these strategies, and elucidates some of the most significant applications of the obtained products.- See more at: http://www.eurekaselect.com/124858/article#sthash.FYdLDiDb.dpu
Biogenic amines profile and concentration in commercial milks for infants and young children
No full textCommercial milks for infants and young children (CMIYC) received much attention during last years for
their impact on the nutritional status, health and development of the new-born and babies. Among
possible contaminants contained in these foods, biogenic amines (BAs) have rarely been determined
although they can exert toxic effects in humans if ingested at high concentrations. Spermine, spermidine,
putrescine, histamine, tyramine, β-phenylethylamine and cadaverine have been quantified in
CMIYC samples by LC-UV after derivatisation with dansyl-chloride. Once optimised in terms of linearity
(R2 ≥ 0.989), recovery percentages (92.9–97.3), LOD (0.2–0.4 μg g−1 or 0.03–0.05 μgmL−1 depending on
the samples), LOQ (0.5–1.0 μg g−1 and 0.08–0.13 μgmL−1 depending on the samples) and repeatability
(0.1–0.2 intra-day; 0.2–0.4 inter-day), the method has been applied to real samples. Very low total BAs
concentrations have been found in reconstituted (1.18–3.12 mg L−1) and liquid milks (0.33–2.30 mg
L−1), with different biogenic amine profiles and distributions. A risk assessment based on the available
information regarding Acute Reference Doses of histamine and tyramine, as well as the application of
common Biogenic Amine Indexes, showed that none of the analysed samples represented a possible
risk for babies, also considering a worst case evaluation. These findings confirmed the strict safety and
quality protocols adopted during the production of CMIYC
Flavonoid-based pH-responsive hydrogels as carrier of unstable drugs in oxidative conditions
No full textIn this study, pH-responsive hydrogels, synthesized by the coupling reaction of polyacrylic acid and catechin, are proposed as carriers of oxidable drugs toward the GI tract. The presence of polyphenolic moieties in the network gives the polymers properties suitable for the release of unstable drugs in oxidative conditions. The characterization of the hydrogels is obtained by means of morphological and physico-chemical analyses, antioxidant assays and evaluation of the swelling behavior in media simulating the gastric (pH 1.0) and the intestinal (pH 7.4) tracts. The hydrogels are tested as pH-responsive carriers in in vitro release studies of folic acid and thiamine, two model drugs easily degraded by oxidative conditions simulated by UV irradiation and t-butyl hydroperoxide treatment, respectively. Results show that catechin-based carriers are able to control the release of drugs at different pH values, giving a remarkable improvement in the stability of the therapeutics
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