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Filme biodegradável à base de fécula de mandioca como potencial indicador de mudança de pH. / Biodegradable film based on cassava starch as patential indicator of pH change.Zetty Arenas, Ana Maria 26 June 2012 (has links)
A cada dia é mais crescente a necessidade e interesse no desenvolvimento de embalagens competitivas e com maior valor agregado. Visando atender a necessidade de consumidores cada vez mais exigentes e preocupados com o meio ambiente, este trabalho propôs o uso do pigmento natural antocianina no desenvolvimento de filmes biodegradáveis para potencial uso como embalagem inteligente, indicadora de mudança de pH. Os filmes foram elaborados pela técnica de casting tendo como formulação base fécula de mandioca (Manihot esculenta Crantz), argila esmectita sódica, glicerol, etanol e água, e incorporados com duas concentrações de antocianina (0,05 e 0,10) g/100 g de solução filmogênica, e em uma segunda fase, ácido cítrico foi incorporado à matriz polimérica a fim de estudar a influência do pH da solução filmogênica (2,8 e 4,3) sobre o desempenho do filme empregado como embalagem. Os filmes foram avaliados quanto as suas propriedades mecânicas (resistência máxima à tração e porcentagem de elongação na ruptura), físico-químicas (atividade de água, umidade, espessura), de barreira (permeabilidade ao vapor dágua e ao oxigênio) e análise de mudança de cor. Em seguida à caracterização, a atividade indicadora de pH foi testada com peixe cru embalado em recipientes de vidro tampados com o filme. Os recipientes foram acondicionados em temperatura ambiente e sob três temperaturas distintas de refrigeração, sendo que recipientes vazios também fechados com o filme foram usados como controle. A avaliação da atividade indicadora de pH foi realizada por meio da análise de mudança de cor do filme correlacionada com o pH do peixe. Os resultados obtidos foram promissores, uma vez que os filmes avaliados se mostraram bons indicadores de pH, ao mudarem de cor à olho nu em resposta à variação do pH, sendo essa mudança mais acentuada em filmes com maior conteúdo de antocianina. / The interest and need for the development of more competitive, higher value-added packages grow faster each day. For attending the needs of a more demanding, environmentally-concerned group of consumers, the present work proposes the use of natural anthocyanin pigment for the development of biodegradable films to be used as intelligent packaging material capable of indicating pH change. These films, made by employing a technique known as casting, consist of a basic formulation of cassava starch (Manihot esculenta Crantz), sodium smectite clay, glycerol, ethanol, and water, combined with two concentrations of anthocyanin (0.05 and 0.10) g/100 g of a filmogenic solution. In a second phase, citric acid was added to the polymer matrix in order to study the influence of the filmogenic solution pH (2.8 and 4.3) on the packaging performance of the films. These materials were assessed according to their mechanical properties (tensile strength at break and elongation at break percentage), physical and chemical properties (water activity, moisture content and thickness), barrier properties (water vapor and oxygen permeability), and color change. After this characterization, the pH-indicating activity was tested with raw fish stored in glass containers sealed with the film. Such containers were firstly exposed to room temperature and subsequently to three different refrigeration temperatures. Similarly, some empty containers also sealed with the same film were used as control. The assessment of the pH-indicating activity was undertaken by analyzing the color change of the film correlated with the pH of the fish. Promising outcomes seemed to have been achieved, since the films that were assessed proved to be efficient pH indicators. The color change was visible to the naked eye in response to pH variation, and such a change was particularly strong in the films with higher anthocyanin content.
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Filme biodegradável à base de fécula de mandioca como potencial indicador de mudança de pH. / Biodegradable film based on cassava starch as patential indicator of pH change.Ana Maria Zetty Arenas 26 June 2012 (has links)
A cada dia é mais crescente a necessidade e interesse no desenvolvimento de embalagens competitivas e com maior valor agregado. Visando atender a necessidade de consumidores cada vez mais exigentes e preocupados com o meio ambiente, este trabalho propôs o uso do pigmento natural antocianina no desenvolvimento de filmes biodegradáveis para potencial uso como embalagem inteligente, indicadora de mudança de pH. Os filmes foram elaborados pela técnica de casting tendo como formulação base fécula de mandioca (Manihot esculenta Crantz), argila esmectita sódica, glicerol, etanol e água, e incorporados com duas concentrações de antocianina (0,05 e 0,10) g/100 g de solução filmogênica, e em uma segunda fase, ácido cítrico foi incorporado à matriz polimérica a fim de estudar a influência do pH da solução filmogênica (2,8 e 4,3) sobre o desempenho do filme empregado como embalagem. Os filmes foram avaliados quanto as suas propriedades mecânicas (resistência máxima à tração e porcentagem de elongação na ruptura), físico-químicas (atividade de água, umidade, espessura), de barreira (permeabilidade ao vapor dágua e ao oxigênio) e análise de mudança de cor. Em seguida à caracterização, a atividade indicadora de pH foi testada com peixe cru embalado em recipientes de vidro tampados com o filme. Os recipientes foram acondicionados em temperatura ambiente e sob três temperaturas distintas de refrigeração, sendo que recipientes vazios também fechados com o filme foram usados como controle. A avaliação da atividade indicadora de pH foi realizada por meio da análise de mudança de cor do filme correlacionada com o pH do peixe. Os resultados obtidos foram promissores, uma vez que os filmes avaliados se mostraram bons indicadores de pH, ao mudarem de cor à olho nu em resposta à variação do pH, sendo essa mudança mais acentuada em filmes com maior conteúdo de antocianina. / The interest and need for the development of more competitive, higher value-added packages grow faster each day. For attending the needs of a more demanding, environmentally-concerned group of consumers, the present work proposes the use of natural anthocyanin pigment for the development of biodegradable films to be used as intelligent packaging material capable of indicating pH change. These films, made by employing a technique known as casting, consist of a basic formulation of cassava starch (Manihot esculenta Crantz), sodium smectite clay, glycerol, ethanol, and water, combined with two concentrations of anthocyanin (0.05 and 0.10) g/100 g of a filmogenic solution. In a second phase, citric acid was added to the polymer matrix in order to study the influence of the filmogenic solution pH (2.8 and 4.3) on the packaging performance of the films. These materials were assessed according to their mechanical properties (tensile strength at break and elongation at break percentage), physical and chemical properties (water activity, moisture content and thickness), barrier properties (water vapor and oxygen permeability), and color change. After this characterization, the pH-indicating activity was tested with raw fish stored in glass containers sealed with the film. Such containers were firstly exposed to room temperature and subsequently to three different refrigeration temperatures. Similarly, some empty containers also sealed with the same film were used as control. The assessment of the pH-indicating activity was undertaken by analyzing the color change of the film correlated with the pH of the fish. Promising outcomes seemed to have been achieved, since the films that were assessed proved to be efficient pH indicators. The color change was visible to the naked eye in response to pH variation, and such a change was particularly strong in the films with higher anthocyanin content.
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Printed RFID Humidity Sensor Tags for Flexible Smart SystemsFeng, Yi January 2015 (has links)
Radio frequency identification (RFID) and sensing are two key technologies enabling the Internet of Things (IoT). Development of RFID tags augmented with sensing capabilities (RFID sensor tags) would allow a variety of new applications, leading to a new paradigm of the IoT. Chipless RFID sensor technology offers a low-cost solution by eliminating the need of an integrated circuit (IC) chip, and is hence highly desired for many applications. On the other hand, printing technologies have revolutionized the world of electronics, enabling cost-effective manufacturing of large-area and flexible electronics. By means of printing technologies, chipless RFID sensor tags could be made flexible and lightweight at a very low cost, lending themselves to the realization of ubiquitous intelligence in the IoT era. This thesis investigated three construction methods of printable chipless RFID humidity sensor tags, with focus on the incorporation of the sensing function. In the first method, wireless sensing based on backscatter modulation was separately realized by loading an antenna with a humidity-sensing resistor. An RFID sensor tag could then be constructed by combining the wireless sensor with a chipless RFID tag. In the second method, a chipless RFID sensor tag was built up by introducing a delay line between the antenna and the resistor. Based on time-domain reflectometry (TDR), the tag encoded ID in the delay time between its structural-mode and antenna-mode scattering pulse, and performed the sensing function by modulating the amplitude of the antenna-mode pulse. In both of the above methods, a resistive-type humidity-sensing material was required. Multi-walled carbon nanotubes (MWCNTs) presented themselves as promising candidate due to their outstanding electrical, structural and mechanical properties. MWCNTs functionalized (f-MWCNTs) by acid treatment demonstrated high sensitivity and fast response to relative humidity (RH), owing to the presence of carboxylic acid groups. The f-MWCNTs also exhibited superior mechanical flexibility, as their resistance and sensitivity remained almost stable under either tensile or compressive stress. Moreover, an inkjet printing process was developed for the f-MWCNTs starting from ink formulation to device fabrication. By applying the f-MWCNTs, a flexible humidity sensor based on backscatter modulation was thereby presented. The operating frequency range of the sensor was significantly enhanced by adjusting the parasitic capacitance in the f-MWCNTs resistor. A fully-printed time-coded chipless RFID humidity sensor tag was also demonstrated. In addition, a multi-parameter sensor based on TDR was proposed.The sensor concept was verified by theoretical analysis and circuit simulation. In the third method, frequency-spectrum signature was utilized considering its advantages such as coding capacity, miniaturization, and immunity to noise. As signal collision problem is inherently challenging in chipless RFID sensor systems, short-range identification and sensing applications are believed to embody the core values of the chipless RFID sensor technology. Therefore a chipless RFID humidity sensor tag based on near-field inductive coupling was proposed. The tag was composed of two planar inductor-capacitor (LC) resonators, one for identification, and the other one for sensing. Moreover, paper was proposed to serve as humidity-sensing substrate for the sensor resonator on accounts of its porous and absorptive features. Both inkjet paper and ordinary packaging paper were studied. A commercial UV-coated packaging paper was proven to be a viable and more robust alternative to expensive inkjet paper as substrate for inkjet-printed metal conductors. The LC resonators printed on paper substrates showed excellent sensitivity and reasonable response time to humidity in terms of resonant frequency. Particularly, the resonator printed on the UV-coated packaging paper exhibited the largest sensitivity from 20% to 70% RH, demonstrating the possibilities of directly printing the sensor tag on traditional packages to realize intelligent packaging at an ultra-low cost. / <p>QC 20150326</p>
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Étude de l'évolution du ''smart packaging'' alimentaire et analyse des marchés des pays industrialisés : actualité et tendances / Smart packaging market evolution in the industrialized countries : today's and future trendsMonborren-Benabdillah, Linda 04 May 2015 (has links)
D’un simple outil de protection des aliments et de transport des objets, l’emballage est devenu une science qui évolue sans répit. Depuis peu, l’emballage franchit une nouvelle étape, d’un outil de vente, il devient un acteur qui prolonge la durée de conservation des aliments et les préserve, ainsi qu'un langage censé parler au producteur, au distributeur et même au consommateur. En contradiction avec la plupart des législations qui définissaient l’emballage comme inerte, les nouveaux emballages sont des éléments actifs ou intelligents. Cependant, ce qu’en Europe et aux Etats-Unis on considère être de nouvelles technologies d’emballage, existe au Japon depuis plusieurs décennies déjà. Tout l’enjeu est donc de comprendre pourquoi et comment, sur un marché mondialisé où la course vers l’innovation et les nouvelles technologies est permanente, le Smart Packaging arrive en Europe avec quarante ans de retard. Cette étude a pour objectif de donner un aperçu sur les technologies, les applications existantes et les enjeux du Smart Packaging, ainsi que sur les perspectives des innovations. Il est par ailleurs essentiel d'analyser la pérennité et la viabilité des nouvelles technologies de l’emballage dans le secteur agroalimentaire des pays industrialisés, en apportant un éclairage sur l’actualité du marché ainsi que sur sa dynamique et sur les tendances majeures de son évolution à court et à long termes. Le projet a de même pour but de développer les stratégies de marketing, d’export et de gestion des risques à appliquer à un marché international, et de définir les cadres réglementaires des principaux pays industrialisés et les risques pour l’environnement et le consommateur. / Packaging used to be a very common, unnoticed, everyday life object for food protection and transportation. It is now a whole scientific subject that evolves on a daily basis. Recently packaging has crossed a new threshold: it is no more a simple marketing tool. Today packaging acts as a food protector that prolongs the shelf life and provides information to manufacturers, distributors, and even consumers. In complete contradiction with all the legislation that defined it as an inert object, new packaging technologies are active and intelligent devices. However, what is called in Europe and the United States a new technology, has been marketed in Japan for decades. The challenge is to understand how and why Smart Packaging was so late to enter Europe and the US at a time when globalization in trade and communication are stronger than ever, and the race for innovation and new technologies is permanent. The main objective of this report is to give insights into today’s market stakes, its opportunities, major trends and short and long term evolution, as well as its growth potential and the major factors that influence it on one hand. On the other hand it provides analysis for the future and the viability of the new technologies in food and drink sectors on developed countries markets. To achieve these purposes, it is essential to give an overview of the existing technologies and applications and explain the stakes of using Smart Packaging, as well as innovation perspectives. Moreover, this projects highlights how the companies meet the challenge of developing marketing, exportation and risk strategies on a global market, whithin the boundaries of the regulatory frameworks and risks for the environment and the consumer.
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Jednorázový sensor amoniaku pro inteligentní obaly / Disposable sensor of ammonium for intelligent packagingNentvichová, Aneta January 2021 (has links)
This diploma thesis is focused on the problematic of the smart packaging and deals with the preparation of disposable ammonia sensors/indicators and the subsequent color measurement of prepared sensors/indicators using the CIE L* a* b* color space. The theoretical part of the diploma thesis focuses on active and intelligent packaging, using ammonia sensors/indicators. The emphasis is placed on the main components of the sensor/indicator, i.e., chitosan as a polymer and curcumin as a dye. The theoretical part also includes the problematic of meat degradation, which plays a very important role in this thesis. The experimental part was divided into two parts. The first part was to prepare layers that will respond in different colors based on the concentrations of ammonia. Prepared layers were sensitive to ammonia across all concentrations, and based on this result, ascorbic acid was applied to compositions to achieve a calibration retention of the selected amount of ammonia. The second minor part of the experiment was the application of selected layers to packages with real meat.
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