scholarly journals Mobility of pectin methylesterase in pectin/cellulose gels is enhanced by the presence of cellulose and by its catalytic capacity

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Estelle Bonnin ◽  
Camille Alvarado ◽  
Marie-Jeanne Crépeau ◽  
Brigitte Bouchet ◽  
Catherine Garnier ◽  
...  
2021 ◽  
Vol 13 (11) ◽  
pp. 6059
Author(s):  
Irati Otamendi-Irizar ◽  
Olatz Grijalba ◽  
Alba Arias ◽  
Claudia Pennese ◽  
Rufino Hernández

Cities are the main contributors to pollution, resource consumption and social inequalities. Therefore, they should play a key role in the path towards a more sustainable scenario in line with SDGs and different Urban Agendas. However, there are still difficulties in their implementation and citizen can play a central role. This paper presents the Urban Action Structures (UAS), understood as entities with a catalytic capacity with respect to innovative urban policies. Methodologically, firstly, a prospective analysis from regional to international level has been developed, making it possible to identify innovative lines of action in the field of sustainable cities. Secondly, the study has focused on identifying and studying UAS that can make it possible to implement the lines of action previously identified. This paper has shown that there are already social structures that can be understood as UAS, since they implement actions aligned with the priorities of the Urban Agenda for the Basque Country and, therefore, of the SDGs. The research concludes that UAS can play a key role in facilitating the implementation of Urban Agendas. Hence, urban policies should favor the generation of UAS, in order to promote long-term urban development and to foster a more sustainable spatial planning.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1301
Author(s):  
Oscar E. Medina ◽  
Jaime Gallego ◽  
Sócrates Acevedo ◽  
Masoud Riazi ◽  
Raúl Ocampo-Pérez ◽  
...  

This study focuses on evaluating the volumetric hydrogen content in the gaseous mixture released from the steam catalytic gasification of n-C7 asphaltenes and resins II at low temperatures (<230 °C). For this purpose, four nanocatalysts were selected: CeO2, CeO2 functionalized with Ni-Pd, Fe-Pd, and Co-Pd. The catalytic capacity was measured by non-isothermal (from 100 to 600 °C) and isothermal (220 °C) thermogravimetric analyses. The samples show the main decomposition peak between 200 and 230 °C for bi-elemental nanocatalysts and 300 °C for the CeO2 support, leading to reductions up to 50% in comparison with the samples in the absence of nanoparticles. At 220 °C, the conversion of both fractions increases in the order CeO2 < Fe-Pd < Co-Pd < Ni-Pd. Hydrogen release was quantified for the isothermal tests. The hydrogen production agrees with each material’s catalytic activity for decomposing both fractions at the evaluated conditions. CeNi1Pd1 showed the highest performance among the other three samples and led to the highest hydrogen production in the effluent gas with values of ~44 vol%. When the samples were heated at higher temperatures (i.e., 230 °C), H2 production increased up to 55 vol% during catalyzed n-C7 asphaltene and resin conversion, indicating an increase of up to 70% in comparison with the non-catalyzed systems at the same temperature conditions.


Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1649
Author(s):  
Hyang-Lan Eum ◽  
Seung-Hyun Han ◽  
Eun-Jin Lee

Improved methods are needed to extend the shelf life of strawberry fruits. The objective of this study was to determine the postharvest physiological mechanism of high-CO2 treatment in strawberries. Harvested strawberries were stored at 10 °C after 3 h of exposure to a treatment with 30% CO2 or air. Pectin and gene expression levels related to cell wall degradation were measured to assess the high-CO2 effects on the cell wall and lipid metabolism. Strawberries subjected to high-CO2 treatment presented higher pectin content and firmness and lower decay than those of control fruits. Genes encoding cell wall-degrading enzymes (pectin methylesterase, polygalacturonase, and pectate lyase) were downregulated after high-CO2 treatment. High-CO2 induced the expression of oligogalacturonides, thereby conferring defense against Botrytis cinerea in strawberry fruits, and lowering the decay incidence at seven days after its inoculation. Our findings suggest that high-CO2 treatment can maintain strawberry quality by reducing decay and cell wall degradation.


2021 ◽  
Vol 11 (6) ◽  
pp. 2842 ◽  
Author(s):  
Ammar B. Altemimi ◽  
Asaad R. S. Al-Hilphy ◽  
Tarek Gamal Abedelmaksoud ◽  
Salam A. Aboud ◽  
Laxmikant S. Badwaik ◽  
...  

The effect of infrared radiation (IR) on the physicochemical characteristics, pectin methylesterase activity (PME), hydroxymethylfurfural (HMF) content, microbiological activity, color, and sensory aspects on black lime juice was studied. IR was compared to conventional thermal heating (CTH) in batch infrared extraction pasteurizer, designed to allow both infrared and conventional heating. IR resulted in a reduction in pH and Brix values and a mild increase in titratable acidity, as compared to CTH and control. After 60 days at 5 °C, the ascorbic acid percentage was decreased by 24.90%, 29.75%, and 58.31% in the control, IR and CTH, respectively. The total amount of phenols in juice treated with IR was higher as compared to CTH and control, while there was a significant decrease in the antioxidant activity. The statistical analysis reflected significantly low (p < 0.05) activity of PME for IR samples as compared to CTH and control. The amount of Hydroxymethylfurfural (HMF) in all juice samples steadily increased during the storage at 5 °C in 60 days. The microbial content of control was 3.85 log cfu/mL after 60 days at 5 °C, while it was 2.1 log cfu/mL for IR which reflected a significant difference between the IR, CTH, and control samples. Additionally, color and sensory analysis of IR treated sample when compared to control, reflected similar attributes. Overall, IR was found to be an excellent substitute for the preservation of black lime juice as a rapid pasteurization technique with less heat exposure; wherein the nutrition and health benefits of the juice could be maintained for a minimum period of 60 days.


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