Deterioration of metal–organic framework crystal structure during fabrication of poly(L-lactic acid) mixed-matrix membranes

Poly(l-lactic acid) (PLLA) and metal–organic framework (MOF) mixed-matrix membranes were prepared by melt extrusion of PLLA with 5% (w/w) of either activated or water-saturated Cu3(BTC)2 (Cu3(C9H3O6)2(H2O)3·xH2O, HKUST-1). The morphology and the stability of injection-molded samples were evaluated using thermogravimetric analysis, differential scanning calorimetry, gel permeation chromatography, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The presence of activated and saturated MOF crystals increased the cold crystallization onset temperature as compared to neat PLLA. This can be attributed to the MOF crystals incorporated in the PLLA matrix, which decreased the mobility of PLLA and thus impeded the crystallization process. According to the XRD results, the activated MOF crystals were successfully incorporated into the PLLA matrix without altering the crystal structure of the MOF. Moreover, the findings from permeability and tensile tests as well as SEM imaging indicated good interfacial interactions between PLLA and activated MOF. However, during melt extrusion of PLLA with saturated MOF, water molecules from the saturated MOF altered the MOF crystal structure and contributed to the degradation of the PLLA polymer by reducing its molecular weight by around 21%. © 2013 Society of Chemical Industr

Toughening of poly(\u3csub\u3eL\u3c/sub\u3e-lactic acid) with Cu\u3csub\u3e3\u3c/sub\u3eBTC\u3csub\u3e2\u3c/sub\u3e metal organic framework crystals

Poly(l-lactic acid) (PLLA) and metal organic framework (MOF) composites were prepared by melt extrusion of PLLA with 5, 10 and 20% w/w of activated Cu3(BTC)2 MOF. The morphology and stability of injection-molded samples were evaluated using thermogravimetric analysis, differential scanning calorimetry (DSC), gel permeation chromatography, X-ray diffraction, and scanning electron microscopy (SEM). The composites showed improved toughness during the tensile tests as compared to the neat PLLA matrix. Toughness mechanism of the composites was studied using SEM and rheological studies. SEM images indicated that cavitation induced by debonding at the interface of PLLA and MOF particles during the uniaxial stress was primarily responsible for the improved toughness of the composites. The SEM images of the composites, the solid like plateau observed in the PLLA composites during the parallel plate rheology at low frequency, and the decrease in the cold crystallization enthalpy during the developed composites indicate potential for various applications, which include gas separation, energy and active packaging

Synthesis of nanoporous carbohydrate metal-organic framework and encapsulation of acetaldehyde

Gamma cyclodextrin (γ-CD) metal organic frameworks (CDMOFs) were synthesized by coordinating γ-CDs with potassium hydroxide (KOH), referred hereafter as CDMOF-a, and potassium benzoate (C7H5KO2), denoted as CDMOF-b. The obtained CDMOF structures were characterized using nitrogen sorption isotherm, thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). High surface areas were achieved by the γ-CD based MOF structures where the Langmuir specific surface areas (SSA) of CDMOF-a and CDMOF-b were determined as 1376 m2 g−1 and 607 m2 g−1; respectively. The dehydrated CDMOF structures demonstrated good thermal stability up to 250 °C as observed by the TGA studies. XRD results for CDMOF-a and CDMOF-b reveal a body centered-cubic (BCC) and trigonal crystal system; respectively. Due to its accessible porous structure and high surface area, acetaldehyde was successfully encapsulated in CDMOF-b. During the release kinetic studies, we observed peak release of 53 μg of acetaldehyde per g of CDMOF-b, which was 100 times greater than previously reported encapsulation in β-CD. However, aldol condensation reaction occurred during encapsulation of acetaldehyde into CDMOF-a. This research work demonstrates the potential to encapsulate volatile organic compounds in CDMOF-b, and their associated release for applications including food, pharmaceuticals and packaging

Perfluorooctanoic Acid and Perfluorooctane Sulfonate in Human Milk: First Survey from Lebanon

Human milk is the primary source of nutrition for infants in their first year of life. Its potential contamination with perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), a group of toxic man-made chemicals, is a health concern that may threatens infants’ health. Our study aims to assess the levels of PFOA and PFOS in the breast milk of Lebanese lactating mothers and the maternal factors associated with their presence. High-performance liquid chromatography (HPLC) coupled with a Micromass Quattro micro API triple quadrupole mass spectrometer was used to detect the level of contamination in 57 collected human milk samples. PFOA and PFOS were present in 82.5% and 85.7% of the samples, respectively, while PFOA levels ranged between 120 and 247 pg/mL with a median of 147 pg/mL, and those of PFOS ranged between 12 and 86 pg/mL with a median of 27.5 pg/mL. The median contamination for PFOA exceeded the threshold set by the European Food Safety Authority (EFSA) (60 pg/mL); however, that of PFOS was below the threshold (73 pg/mL). The consumption of bread, pasta, meat, and chicken more than twice per week and that of white tubers and roots at least once per week was significantly associated with higher levels of PFOA (p < 0.05). No significant association was found between maternal age, BMI, parity, level of education, place of residence, source of water used, and smoking with the levels of PFOA and PFOS in the human milk. Additionally, the consumption of cereals at least twice per week was significantly associated with higher levels of PFOS. These findings call for actions to improve the local environmental and agricultural practices, and the regulations and standards for inspecting imported food. It is important to highlight that the benefits of breastfeeding outweigh the reported contamination with PFOS and PFOA in our study

The Determinants of Household Food Waste Generation and its Associated Caloric and Nutrient Losses: The Case of Lebanon.

Food waste has a great impact on food and nutrition security, the environment, and global, regional as well as national economies. However, little is known about the associated nutrient loss embedded in wasted foods, especially in developing countries, with Lebanon being a case in point. The present paper uses data gathered from a survey of 250 households conducted in Beirut, Lebanon, in which respondents filled 7-day food waste diaries in order to investigate the drivers of food waste generation at the household level and its dietary content. The results show that food waste is approximately 0.2 kg per capita per day in urban Lebanon. This wasted food contains on average 451.2 kcal, 37.5 g carbohydrates, 14.9 g protein, 2.9 g dietary fiber, 2.4 μg vitamin D, 165.2 mg calcium and 343.2 mg potassium. Furthermore, a Tobit analysis of the socio-demographic and behavioral drivers of food waste generation was conducted. This analysis shows that being the sole homeowner, spending more on food, having a larger number of household members, being ready to eat everything prepared, and tending not to buy special offers, significantly increases household food waste generation, at least in terms of physical weight. This is the first study conducted in Lebanon and the Middle East aiming at investigating food waste, and the associated nutrient loss as well as the drivers of food waste generation at the household level. This work could help provide evidence for policymakers to address both food and nutrition security issues in Lebanon

Combined effects of thymol, carvacrol and packaging on the shelf-life of marinated chicken

The demand for marinated chicken worldwide, is continuously growing. To date, limited data on addition of active components of Essential Oils (EOs) to marinades for chicken preservation are available. The antimicrobial effect of carvacrol and thymol, added at 0.4 and 0.8% v/w to marinated fresh chicken, stored in air and under vacuum packaging (VP), for 21 days at 4 °C, was examined. The samples were monitored for microbiological (total viable count (TVC), lactic acid bacteria (LAB), Brochothrix thermosphacta, Pseudomonas spp., total coliforms, Escherichia coli, yeasts and molds) and sensory attributes (odor characteristics). Our data supports that among the tested microorganisms, Pseudomonas spp., LAB and B. thermosphacta were the most dominant microbiota in the marinated chicken samples. Additionally, the use of active EOs components, especially the higher concentration (0.8% v/w) in combination with VP, retarded the growth of spoilage microbiota and resulted in a significant reduction of about 2.9–3.1 log cfu/g and a microbiological shelf-life extension of marinated chicken by>6 days, as judged by TVC data. Interestingly, the combination of active components of EOs at the lower concentration (0.4% v/w) and packaging (air or vacuum) resulted in a significant sensorial shelf-life extension of 15 and>21 days, as compared to the controls' shelf-life of 9 days. The results of our study demonstrated the potential of the active components, carvacrol and thymol, as natural effective antimicrobial hurdles to control the growth of spoilage microorganisms in marinated chicken meat.Faculty of Agricultural and Food Sciences, American University of Beiru

A novel method to measure the glass and melting transitions of pharmaceutical powders

A method to measure thermo-mechanical properties of pharmaceutical and polymeric powders was developed The measurements are conducted by characterizing the material's response to applied acoustic waves Measurements were performed using griseofulvin, felodipine and indomethacin as model drugs and polyethylene oxide (MW 200,000, 900,000, 2,000,000 Da) as model polymers. The method employed measures the mechanical Impedance enabled the calculation of the powder theological and thermo-mechanical properties. Measurements attained with this new technique are compared with measurements made using differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The new method detects the melting and glass transitions events while providing complementary information to that provided by DSC and DMA (C) 2010 Elsevier B.V. All rights reserve

Intensifying Effects of Climate Change in Food Loss: A Threat to Food Security in Turkey

Turkey is increasingly concerned about the effects of climate change, weather unpredictability, and severe events on agricultural production, food loss, and livelihoods. Turkey has long struggled against climate variability and catastrophic climatic events to prevent further declines in agricultural output. This study assessed the risk of climate change in Turkey from the perspective of loss in food grains and food security domain considering exposure to extreme climate events using the data from 1991 to 2019. This paper makes a theoretical contribution to the literature by identifying the relationship between food waste and food import, food prices and economic growth. It also makes an empirical contribution by administering and econometrically analyzing the impact of the loss of food grains on the aforementioned independent variables. Policy implications for the current national agriculture policy were provided using the vector auto-regression (VAR) model and derivative analysis. Food grain loss negatively correlates with food security since it increases reliance on food imports from outside. Moreover, the losses in food supplies contributes greatly to price increases. The GDP growth rate, however, was shown to be a feeble instigator. Climate change threatens food security, and the country&rsquo;s progress toward sustainable development objectives is hampered in general, particularly concerning no poverty and zero hunger goals. In conclusion, climate change and its associated factors harm Turkey&rsquo;s food security and economy

A review on hospital food waste quantification, management and assessment strategies in the eastern Mediterranean region

Background: Hospital food wastage has been identified as a significant issue within the foodservice sector. Numerous studies have shed the light on the amount of food waste in hospitals, along with its financial and environmental implications. Consequently, reducing food waste in hospitals has become a priority for the foodservice management sector in the Eastern Mediterranean Region (EMR). Aims: This review aims to examine studies on food waste in the hospitals of the EMR countries, and highlight research gaps in quantification, management, and assessment strategies in this region. Methods: PubMed and Google Scholar databases were searched between January 6 and September 1, 2023, to identify relevant articles published up to 2023 in the EMR. Results: Six studies were included in this review. Among EMR countries, only Iran, Saudi Arabia, and Qatar have assessed food waste at hospitals. The average food waste in the EMR represents 25.4 % of total food served. Factors contributing to food waste include clinical issues, food preferences, meal timing, and ward sections. Patient's plate waste reduce dietary intake, affects patient's nutritional status and predispose to malnutrition. While some strategies to reduce plate waste have been proposed in many countries, there is a notable lack of food and food-related waste management policies and programs in hospitals food services in the EMR. Conclusion: This review summarizes the hospital's food-related waste assessment, quantifications, and management used by hospitals in the EMR. This review is a benchmark for the EMR's hospitals to work on adopting proactive measures as a general strategy to move toward food and food-related waste reduction