scholarly journals Development of Breathable Pebax®/PEG Films for Optimization of the Shelf-Life of Fresh Agri-Food Products

Membranes ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 692
Author(s):  
Thibaut Préfol ◽  
Olivier Gain ◽  
Guillaume Sudre ◽  
Fabrice Gouanvé ◽  
Eliane Espuche
Keyword(s):  
Polyethylene Glycol ◽  
Shelf Life ◽  
Transport Properties ◽  
Food Packaging ◽  
Weight Ratio ◽  
Ternary Blend ◽  
Scanning Calorimetry ◽  
Wide Range ◽  
Fresh Products ◽  
Over Time

In this work, thin transparent breathable films were prepared for food packaging applications. The films were obtained by the solvent casting method from both the binary blends Pebax® MH1657 copolymer/ hydroxyl-terminated polyethylene glycol (PEGOH) and Pebax® MH1657/polyethylene glycol dimethyl ether (PEGDME) as well as the ternary blend Pebax® MH1657/PEGOH/PEGDME with a 50/50 and 37.5/62.5 PEGOH/PEGDME weight ratio for additive amounts comprised between 0 and 50 wt.%. The microstructure of these materials was investigated by differential scanning calorimetry (DSC) and wide-angle X-ray scattering (WAXS) analyses. Regardless of the PEG’s nature, for a PEG amount inferior to 30 wt.%, the Pebax® and PEG phases were totally miscible. For higher amounts, a phase separation was obtained. In the presence of PEG, a decrease in crystallinity was obtained. The effects of the nature and amount of PEG on the thermo-mechanical, hydration, and gas (CO2, O2) transport properties were investigated. A study of the film’s stability in terms of composition over time was also performed. From this work, a wide range of films could be proposed with a stable composition over time and adjustable mechanical and gas transport properties for the prolongation of the shelf-life of highly breathable fresh products.

Specific Heat Measurements of Ti6Al4V/Nano SiCp Composite

2017 ◽  
Vol 14 (1) ◽  
pp. 742-746
Author(s):  
S Krishnamohan ◽  
S Ramanathan ◽  
V Ramakrishnan
Keyword(s):  
Heat Capacity ◽  
Weight Ratio ◽  
Thermal Control ◽  
Ti6al4v Alloy ◽  
Thermal Design ◽  
Thermal Method ◽  
Scanning Calorimetry ◽  
Low Weight ◽  
Wide Range ◽  
Materials Used

The elevated strength, low weight ratio and excellent corrosion resistance intrinsic to titanium and its alloys has led to a wide range of successful applications which ensures high levels of unswerving performance in aerospace. The performance of the Thermal Control System extremely depends on the thermal behavior of the materials used in its elements. The measurements of the thermal properties of materials are necessary for better understanding of the thermal design. Differential scanning calorimetry (DSC) is the most extensively used thermal method for finding wealth of information about a material. The heat capacity (Cp) of a material was established quantitatively using DSC. The measurement was made by heating a very small quantity of the Ti6Al4V alloy and Ti6Al4V/Nano SiCp composites. Mechanical alloying (MA) and Powder metallurgy (P/M) techniques were used to fabricate the Ti6Al4V alloy and Ti6Al4V/ nano SiCp composites. The heat flow reaction was recorded as a function of definite sample temperature range from −100 °C to 375 °C. The measurements of the heat capacity of each sample in three runs were recorded by DSC. The heat capacity (Cp) of specimens is reported in this study.

scholarly journals CONSUMER EXPECTATIONS TOWARDS INNOVATIVE FOOD PACKAGING

2021 ◽  
Vol 1 (54) ◽  
Author(s):  
Małgorzata Górka ◽  
◽  
Bogusław Ślusarczyk ◽  
Jolanta Baran ◽  
Elżbieta Brągiel ◽  
...  
Keyword(s):  
Shelf Life ◽  
Food Packaging ◽  
Important Change ◽  
Active Packaging ◽  
Point Of View ◽  
Communication Function ◽  
Food Market ◽  
Intelligent Communication ◽  
Fresh Products ◽  
Definition Of

Due to the growing interest of consumers in the consumption of fresh products with increased shelf life, producers must provide modern and safe packaging. This is a challenge for food packaging and acts as a driving force in the development of new and improved concepts of packaging technology. The article presents the essence, types and classification of packaging as a factor influencing the choice made by the consumer. In addition, the main attention was paid to the definition of knowledge and attitudes of consumers to this type of packaging used in the food market in the food industry. From the point of view of food consumers, the most important role of packaging is to ensure food safety throughout the logistics chain, from producer to consumer. Smart packaging is packaging that is equipped with features that allow it to track the goods through the logistics chain or control the internal and external environment of the packaging, as well as communicate with the consumer. Such packaging can not only control the quality and safety of the product, but also report its condition to a potential consumer or manufacturer. The advent of intelligent packaging systems has contributed to another important change in the existing perception of packaging, as it transforms the traditional communication function of packaging into an intelligent communication function. Another solution for innovative food packaging is active packaging. Active packaging is a system that, due to chemical, physical and biological actions, actively changes the conditions inside the packaging in order to extend the shelf life and preserve the original quality and sensory properties of food. In active packaging, the product, the environment and the packaging interact, thereby increasing product quality, shelf life and durability. Reasonable and active packaging, in addition to the function of protecting the product from the reaction of external factors and attracting the attention of the customer, is aimed at informing potential buyers about the condition and quality of goods and interaction with packaged foods

Effect of Poly(D-Lactic Acid)-co-Polyethylene Glycol on the Crystallization of Poly(L-Lactic Acid)

2017 ◽  
Vol 751 ◽  
pp. 283-289 ◽  
Author(s):  
Ployrawee Kaewlamyai ◽  
Amornrat Lertworasirikul
Keyword(s):  
Lactic Acid ◽  
Polyethylene Glycol ◽  
Weight Ratio ◽  
Crystallization Rate ◽  
Heat Stability ◽  
Nucleating Agent ◽  
Degree Of Crystallinity ◽  
Poly Lactic Acid ◽  
Infrared Spectrometry ◽  
Scanning Calorimetry

Poly (lactic acid) (PLA) is a biopolymer derived from renewable resources and can be disposed of without creating harm to the environment. PLA can be formed by thermoplastic processes and has good mechanical properties. However, its disadvantages are a high crystallization temperature, slow crystallization rate, poor heat stability and low ductility. In the past, it was found that poly (D-lactic acid) (PDLA) can form complexes with poly (L-lactic acid) (PLLA) and the complexes could accelerate the crystallization and increase the degree of crystallinity of the PLA, but decrease the ductility. It is known that polyethylene glycol (PEG) can improve the ductility of PLLA. In this research, PDLA was copolymerized with PEG in an attempt to improve both crystallization behavior and ductility of PLLA. Poly (D-lactic acid)-co-polyethylene glycol (PDEG) was synthesized by ring opening polymerization using D-lactide and PEG at a D-lactide:PEG weight ratio of 10:3. The PDEG was blended with PLLA with a PDEG content of 0wt% to 50wt% by melt blending process. Fourier transform infrared spectrometry (FT-IR) and X-Ray diffractometry (XRD) confirmed the stereocomplex formation between PDEG and PLLA. Characterization by differential scanning calorimetry (DSC) revealed that crystallization temperatures of the blends were decreased in the presence of PDEG. Storage moduli and tan of the blends obtained from dynamic mechanical analysis (DMA) decreased as PDEG content increased. Polarized optical microscopy (POM) micrographs of blends with PDEG content of 1wt% to 5wt% obviously showed that crystallization rate was increased. PDEG has the potential to be an effective nucleating agent and efficient plasticizer for PLLA.

scholarly journals Ultrasonic Technique for Production of Nanoemulsions for Food Packaging Purposes: A Review Study

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 847
Author(s):  
Hamed Ahari ◽  
Mina Nasiri
Keyword(s):  
Essential Oils ◽  
Shelf Life ◽  
Targeted Delivery ◽  
Food Packaging ◽  
Environmental Concerns ◽  
Food Science ◽  
Food Borne ◽  
Wide Range ◽  
Global Concern ◽  
Review Study

According to the loss of food due to expired shelf life, there is a global concern on food safety among food science researchers, and food microbiologists. So, any approaches contributing to improved food packaging is most welcome. It has been demonstrated that administration of essential oils, fades away the unsolved obstacles of conventional food packaging, reducing environmental concerns compared with conventional food packaging. Along with substantial progresses in nanoscience, there is a great interest toward usage of nanoemulsions-based delivery systems. They have potentials to simplify targeted delivery of compounds in a high surfaced area, aimed at increasing stability, biodegradability, anti-oxidation, and anti-microbial properties. There are a wide range of methods for fabrication of nanoemulsions. Among them, ultrasonic-based approaches have gained an acceptable efficiency for industrial fabrication of essential oils-based nanoemulsions due to refraining from loss of nutrients through non-thermal approaches. In summary, essential-oils based nanoemulsions are significant due to ability for reduction in microbial load of food-borne pathogens, and prolonged shelf life.

scholarly journals Innovations in the food packaging market – intelligent packaging – a review  

2017 ◽  
Vol 35 (No. 1) ◽  
pp. 1-6 ◽  
Author(s):  
Barska Anetta ◽  
Wyrwa Joanna
Keyword(s):  
Shelf Life ◽  
Driving Force ◽  
Food Industry ◽  
Food Packaging ◽  
Intelligent Packaging ◽  
Packaging Technology ◽  
Consumer Interest ◽  
Packaging Industry ◽  
Fresh Products

The manufacturers have to provide modern and safe packaging due to the growing consumer interest in the consumption of fresh products with extended shelf-life and controlled quality. It is a challenge to the food packaging industry and it also acts as a driving force for the development of new and improved concepts of packaging technology. It is in order to meet these needs that intelligent packaging can be applied. This article presents a generation of packaging which allows maintaining and even improving the quality of the packaged product, which is an essential advantage particularly in the food industry. The most important advantage resulting from their use is a reduction in the loss of food products due to the extension of their shelf life.

Improving Wire Sweep Performance by Measuring Degree of Cure of Epoxy Mold Compounds

2011 ◽  
Author(s):  
Sheila Liza B. Dal
Keyword(s):  
Differential Scanning Calorimetry ◽  
Shelf Life ◽  
Trial And Error ◽  
Active Components ◽  
Scanning Calorimetry ◽  
Degree Of Cure ◽  
Electronic Package ◽  
Viscosity Changes ◽  
Epoxy Mold Compounds

Abstract The choice of epoxy mold compound (EMC) for an electronic package is based mostly on how much protection it provides to the active components in the package. But the choice is not a straightforward process. Rather it is mostly trial and error using different assembly parameters to find the most robust material while assembly defects are monitored. One such defect associated to EMC processing is wire sweep, and many studies have shown that it is mainly caused by viscosity changes in the EMC. In this study, samples of EMC in various stages of shelf life and staging times were analyzed for degree of cure using a method called differential scanning calorimetry (DSC). Samples are then processed at assembly for wire sweep measurement. It was found out that degree of cure increases with staging time at different rates for each shelf life. It was also found out that wire sweep did not only increase with degree of cure but it was also found to be predictable with respect to the latter. Using this information, the age and staging limit for each material was identified that would not cause wire sweep issues.

pH-Dependent Thermal Stability of Vibrio cholerae L-asparaginase

2019 ◽  
Vol 26 (10) ◽  
pp. 743-750 ◽  
Author(s):  
Remya Radha ◽  
Sathyanarayana N. Gummadi
Keyword(s):  
Vibrio Cholerae ◽  
Conformational Changes ◽  
Kinetic Studies ◽  
Structural Features ◽  
Structure Stability ◽  
Kcal Mole ◽  
Scanning Calorimetry ◽  
Wide Range ◽  
Ph Dependent ◽  
Ph Range

Background:pH is one of the decisive macromolecular properties of proteins that significantly affects enzyme structure, stability and reaction rate. Change in pH may protonate or deprotonate the side group of aminoacid residues in the protein, thereby resulting in changes in chemical and structural features. Hence studies on the kinetics of enzyme deactivation by pH are important for assessing the bio-functionality of industrial enzymes. L-asparaginase is one such important enzyme that has potent applications in cancer therapy and food industry.Objective:The objective of the study is to understand and analyze the influence of pH on deactivation and stability of Vibrio cholerae L-asparaginase.Methods:Kinetic studies were conducted to analyze the effect of pH on stability and deactivation of Vibrio cholerae L-asparaginase. Circular Dichroism (CD) and Differential Scanning Calorimetry (DSC) studies have been carried out to understand the pH-dependent conformational changes in the secondary structure of V. cholerae L-asparaginase.Results:The enzyme was found to be least stable at extreme acidic conditions (pH< 4.5) and exhibited a gradual increase in melting temperature from 40 to 81 °C within pH range of 4.0 to 7.0. Thermodynamic properties of protein were estimated and at pH 7.0 the protein exhibited ΔG37of 26.31 kcal mole-1, ΔH of 204.27 kcal mole-1 and ΔS of 574.06 cal mole-1 K-1.Conclusion:The stability and thermodynamic analysis revealed that V. cholerae L-asparaginase was highly stable over a wide range of pH, with the highest stability in the pH range of 5.0–7.0.

Characterization of Nostoc muscorum NCCU-442 Derived Poly-3- hydroxybutyrate (PHB) and Polyethylene Glycol (PEG) Blends

2020 ◽  
Vol 10 (3) ◽  
pp. 200-207
Author(s):  
Sabbir Ansari ◽  
Tasneem Fatma
Keyword(s):  
Thermal Properties ◽  
Polyethylene Glycol ◽  
Morphological Properties ◽  
Morphological Alteration ◽  
Nostoc Muscorum ◽  
Microbial Culture ◽  
Polymer Science ◽  
Mixed Microbial Culture ◽  
Scanning Calorimetry ◽  
Casting Technique

Background: Poly-3-hydroxybutyrate (PHB) has attracted much consideration as biodegradable biocompatible polymer. This thermoplastic polymer has comparable material properties to polypropylene. Materials with more valuable properties may result from blending, a common practice in polymer science. Objective: In this paper, blends of PHB (extracted from cyanobacterium Nostoc muscorum NCCU- 442 with polyethylene glycol (PEG) were investigated for their thermal, tensile, hydrophilic and biodegradation properties. Methods: Blends were prepared in different proportions of PHB/PEG viz. 100/0, 98/2, 95/5, 90/10, 80/20, and 70/30 (wt %) using solvent casting technique. Morphological properties were investigated by using Scanning Electron Microscopy (SEM). Differential scanning calorimetry and thermogravimetric analysis were done for thermal properties determination whereas the mechanical and hydrophilic properties of the blends were studied by means of an automated material testing system and contact angle analyser respectively. Biodegradability potential of the blended films was tested as percent weight loss by mixed microbial culture within 60 days. Results: The blends showed good misciblity between PEG and PHB, however increasing concentrations of plasticizer caused morphological alteration as evidenced by SEM micrographs. PEG addition (10 % and above) showed significant alternations in the thermal properties of the blends. Increase in the PEG content increased the elongation at break ratio i.e enhanced the required plasticity of PHB. Rate of microbial facilitated degradation of the blends was greater with increasing PEG concentrations. Conclusion: Blending with PEG increased the crucial polymeric properties of cyanobacterial PHB.

Anti-corruption in History

2017 ◽  
Keyword(s):  
Financial Institutions ◽  
Global Media ◽  
Policy Makers ◽  
The Past ◽  
Human Wellbeing ◽  
Modern Period ◽  
Legitimate Power ◽  
Wide Range ◽  
Scant Attention ◽  
Over Time

Anticorruption in History is the first major collection of case studies on how past societies and polities, in and beyond Europe, defined legitimate power in terms of fighting corruption and designed specific mechanisms to pursue that agenda. It is a timely book: corruption is widely seen today as a major problem, undermining trust in government, financial institutions, economic efficiency, the principle of equality before the law and human wellbeing in general. Corruption, in short, is a major hurdle on the “path to Denmark”—a feted blueprint for stable and successful statebuilding. The resonance of this view explains why efforts to promote anticorruption policies have proliferated in recent years. But while the subjects of corruption and anticorruption have captured the attention of politicians, scholars, NGOs and the global media, scant attention has been paid to the link between corruption and the change of anticorruption policies over time and place. Such a historical approach could help explain major moments of change in the past as well as reasons for the success and failure of specific anticorruption policies and their relation to a country’s image (of itself or as construed from outside) as being more or less corrupt. It is precisely this scholarly lacuna that the present volume intends to begin to fill. A wide range of historical contexts are addressed, ranging from the ancient to the modern period, with specific insights for policy makers offered throughout.

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