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Preparation and optimization of submicron chitosan capsules by water-based electrospraying for food and bioactive packaging applications Texto completo
2017
Sreekumar, Sruthi | Lemke, Philipp | Moerschbacher, Bruno M | Torres-Giner, Sergio | Lagaron, Jose M
In the present study, a well-defined set of chitosans, with different degrees of acetylation (DA) and degrees of polymerization (DP), were processed by solution electrospraying from a water-based solvent. The solution properties, in terms of surface tension, conductivity, viscosity, and pH, were characterized and related to the physico-chemical properties of the chitosans. It was observed that both DA and DP values of a given chitosan, in combination with biopolymer concentration, mainly determined solution viscosity. This was, in turn, the major driving factor that defined the electrosprayability of chitosan. In addition, the physico-chemical properties of chitosans highly influenced solution conductivity and results indicated that the chitosan solutions with low or low-to-medium values of conductivity were the most optimal for electrospraying. The results obtained here also demonstrate that a good process control can be achieved by adjusting the working conditions, i.e . applied voltage, flow-rate, and tip-to-collector distance. Finally, it was also shown that electrosprayability of chitosan with inadequate physico-chemical properties can be improved by solution mixing of very different kinds of this polysaccharide. The resultant electrosprayed submicron chitosan capsules can be applied for encapsulation of food additives and to develop bioactive coatings of interest in food packaging, where these particles alone or containing functional ingredients can be released from the package into the food to promote a health benefit.
Mostrar más [+] Menos [-]The water-energy-food nexus: Is the increasing attention warranted, from either a research or policy perspective? Texto completo
2017
Wichelns, Dennis
In recent years, the notion of a nexus involving water, energy, and food has been gaining attention in the scholarly literature and popular press, due partly to the impetus provided by an international conference on the nexus in 2011, and partly to the increasing interest among researchers and public officials in determining the investments and policies needed to achieve and sustain water, energy, and food security. While the notion of such a nexus is compelling to some observers, interactions involving water, energy, and food have been known and studied for many years by scientists and policy analysts. The need for greater integration of research and policy discourse across sectors and regions has been expressed in international meetings since the late 1940s. In addition, the conceptual basis for including water, energy, and food in the “nexus,” to the exclusion of other resources and inputs is not evident. In many cases, the information excluded from studies claiming to implement a nexus approach might be of greater importance to science and policy than the information included in the analysis. In this paper, I review some of the experience gained in earlier attempts to enhance integration and policy coherence, and to promote systems analysis. The challenges observed in implementing programs of integrated natural resources management (INRM) and integrated water resources management (IWRM), in particular, suggest that efforts to implement a water-energy-food nexus approach will not enhance the policy process in all settings. In sum, it is not clear that the increasing attention given to studies claiming to implement a nexus approach is warranted.
Mostrar más [+] Menos [-]Livestock production and the water challenge of future food supply: Implications of agricultural management and dietary choices Texto completo
2017
Weindl, Isabelle | Bodirsky, Benjamin Leon | Rolinski, Susanne | Biewald, Anne | Lotze-Campen, Hermann | Müller, Christoph | Dietrich, Jan Philipp | Humpenöder, Florian | Stevanović, Miodrag | Schaphoff, Sibyll | Popp, Alexander
Human activities use more than half of accessible freshwater, above all for agriculture. Most approaches for reconciling water conservation with feeding a growing population focus on the cropping sector. However, livestock production is pivotal to agricultural resource use, due to its low resource-use efficiency upstream in the food supply chain. Using a global modelling approach, we quantify the current and future contribution of livestock production, under different demand- and supply-side scenarios, to the consumption of “green” precipitation water infiltrated into the soil and “blue” freshwater withdrawn from rivers, lakes and reservoirs. Currently, cropland feed production accounts for 38% of crop water consumption and grazing involves 29% of total agricultural water consumption (9990km³yr⁻¹). Our analysis shows that changes in diets and livestock productivity have substantial implications for future consumption of agricultural blue water (19–36% increase compared to current levels) and green water (26–69% increase), but they can, at best, slow down trends of rising water requirements for decades to come. However, moderate productivity reductions in highly intensive livestock systems are possible without aggravating water scarcity. Productivity gains in developing regions decrease total agricultural water consumption, but lead to expansion of irrigated agriculture, due to the shift from grassland/green water to cropland/blue water resources. While the magnitude of the livestock water footprint gives cause for concern, neither dietary choices nor changes in livestock productivity will solve the water challenge of future food supply, unless accompanied by dedicated water protection policies.
Mostrar más [+] Menos [-]Mechanism of the high efficiency of the cutting frozen food products using water-jet with polymer additions Texto completo
2017
A. Pogrebnyak | V. Pogrebnyak
<p>The article to determine peculiarities of macromolecule deformation behavior under conditions of a jet-shaping head that would allow to solve the issue related to the mechanism of increasing water-jet cutting power with polymer additions. In converging polyethyleneoxide solution flow macromolecules are forced by a hydrodynamic field to rather strong stretching that causes the dynamic structure formation in solutions. There have been studied experimentally velocity fields and their gradients as well as the degree of macromolecule unrolling under pattern conditions of a jet-shaping head in poluyethyleneoxide solutions flow. In converging polymer solution flow macromolecules are forced by a hydrodynamic field to rather strong (~ 60 % and more) stretching that causes the field restructuring. The determined regularities of macromolecules behavior in the flow under conditions of a jet-shaping head and manifested in this case effects of elastic deformations have paramount importance in understanding the mechanism of «anomalously» high cutting power of water-polymer jet. The work for the first time makes it possible to explain the nature of increased water-jet cutting power with polymer additions when cutting food products. Understanding the nature of increased cutting power of water-polymer jet will make it possible to develop recommendations on choosing regimes for water-polymer jet processing of food products by cutting.</p>
Mostrar más [+] Menos [-]Water‐Energy‐Food Security Nexus in the Eastern Nile Basin: Assessing the Potential of Transboundary Regional Cooperation Texto completo
2017
Al‐Saidi, Mohammad | Elagib, Nadir Ahmed | Ribbe, Lars | Schellenberg, Tatjana | Roach, Emma | Oezhan, Deniz
With increasing demands and pressures on energy, food, and water resources in the region of the Eastern Nile basin, development projects and also potential for conflict along the Nile waters have increased. This study presents data on resource use patterns and reviews literature on the cooperation potential between Egypt, Sudan, and Ethiopia in the sectors of water, energy, and food. It introduces the resource use profiles of the countries in the three sectors and summarizes common challenges to resource security and in regard to cross‐cutting issues, such as climate risks and land degradation. The study also highlights the issues for transboundary cooperation using resources within and beyond the Nile. It emphasizes the importance of regional integration, using current country‐specific potentials for easing river‐sharing conflicts and fostering human development of riparian countries.
Mostrar más [+] Menos [-]Research priorities for managing the impacts and dependencies of business upon food, energy, water and the environment Texto completo
2017
Green, JMH | Cranston, GR | Sutherland, WJ | Tranter, HR | Bell, SJ | Benton, TG | Blixt, E | Bowe, C | Broadley, S | Brown, A | Brown, C | Burns, N | Butler, D | Collins, H | Crowley, H | DeKoszmovszky, J | Firbank, LG | Fulford, B | Gardner, TA | Hails, RS | Halvorson, S | Jack, M | Kerrison, B | Koh, LSC | Lang, SC | McKenzie, EJ | Monsivais, P | O Riordan, T | Osborn, J | Oswald, S | Price Thomas, E | Raffaelli, D | Reyers, B | Srai, JS | Strassburg, BBN | Webster, D | Welters, R | Whiteman, G | Wilsdon, J | Vira, B
Delivering access to sufficient food, energy and water resources to ensure human wellbeing is a major concern for governments worldwide. However, it is crucial to account for the ‘nexus’ of interactions between these natural resources and the consequent implications for human wellbeing. The private sector has a critical role in driving positive change towards more sustainable nexus management and could reap considerable benefits from collaboration with researchers to devise solutions to some of the foremost sustainability challenges of today. Yet opportunities are missed because the private sector is rarely involved in the formulation of deliverable research priorities. We convened senior research scientists and influential business leaders to collaboratively identify the top forty questions that, if answered, would best help companies understand and manage their food-energy-water-environment nexus dependencies and impacts. Codification of the top order nexus themes highlighted research priorities around development of pragmatic yet credible tools that allow businesses to incorporate nexus interactions into their decision-making; demonstration of the business case for more sustainable nexus management; identification of the most effective levers for behaviour change; and understanding incentives or circumstances that allow individuals and businesses to take a leadership stance. Greater investment in the complex but productive relations between the private sector and research community will create deeper and more meaningful collaboration and cooperation. | This work was supportedby the Economic and Social Research Council [Grant Number ES/L01632X/1] and is part of the Nexus Network Initiative. WJS is funded by Arcadia.
Mostrar más [+] Menos [-]Mechanism of the high efficiency of the cutting frozen food products using water-jet with polymer additions Texto completo
2017
Pogrebnyak, A. | Pogrebnyak, V.
<p>The article to determine peculiarities of macromolecule deformation behavior under conditions of a jet-shaping head that would allow to solve the issue related to the mechanism of increasing water-jet cutting power with polymer additions. In converging polyethyleneoxide solution flow macromolecules are forced by a hydrodynamic field to rather strong stretching that causes the dynamic structure formation in solutions. There have been studied experimentally velocity fields and their gradients as well as the degree of macromolecule unrolling under pattern conditions of a jet-shaping head in poluyethyleneoxide solutions flow. In converging polymer solution flow macromolecules are forced by a hydrodynamic field to rather strong (~ 60 % and more) stretching that causes the field restructuring. The determined regularities of macromolecules behavior in the flow under conditions of a jet-shaping head and manifested in this case effects of elastic deformations have paramount importance in understanding the mechanism of «anomalously» high cutting power of water-polymer jet. The work for the first time makes it possible to explain the nature of increased water-jet cutting power with polymer additions when cutting food products. Understanding the nature of increased cutting power of water-polymer jet will make it possible to develop recommendations on choosing regimes for water-polymer jet processing of food products by cutting.</p>
Mostrar más [+] Menos [-]The seafood gap in the food-water nexus literature--issues surrounding freshwater use in seafood production chains Texto completo
2017
Gephart, J.A. | Troell, M. | Henriksson, P.J.G. | Beveridge, M.C. | Verdegem, M. | Metian, M. | Mateos, L.D. | Deutsch, L.
Freshwater use for food production is projected to increase substantially in the coming decades with population growth, changing demographics, and shifting diets. Ensuring joint food-water security has prompted efforts to quantify freshwater use for different food products and production methods. However, few analyses quantify freshwater use for seafood production, and those that do use inconsistent water accounting. This inhibits water use comparisons among seafood products or between seafood and agricultural/livestock products. This 'seafood gap' in the food-water nexus literature will become increasingly problematic as seafood consumption is growing globally and aquaculture is one of the fastest growing animal food sectors in the world. Therefore, the present study 1) reviews freshwater use concepts as they relate to seafood production; 2) provides three case studies to highlight the particular water use concerns for aquaculture, and; 3) outlines future directions to integrate seafood into the broader food-water nexus discussion. By revisiting water use concepts through a focus on seafood production systems, we highlight the key water use processes that should be considered for seafood production and offer a fresh perspective on the analysis of freshwater use in food systems more broadly.
Mostrar más [+] Menos [-]Chemical Characteristics and NaCl Component Behavior of Biochar Derived from the Salty Food Waste by Water Flushing Texto completo
2017
Ye-Eun Lee | Jun-Ho Jo | I-Tae Kim | Yeong-Seok Yoo
Biochar is the product of the pyrolysis of organic materials in a reduced state. In recent years, biochar has received attention due to its applicability to organic waste management, thereby leading to active research on biochar. However, there have been few studies using food waste. In particular, the most significant difference between food waste and other organic waste is the high salinity of food waste. Therefore, in this paper, we compare the chemical characteristics of biochar produced using food waste containing low- and high-concentration salt and biochar flushed with water to remove the concentrated salt. In addition, we clarify the salt component behavior of biochar. Peak analysis of XRD confirms that it is difficult to find salt crystals in flushed char since salt remains in the form of crystals when salty food waste is pyrolyzed washed away after water flushing. In addition, the Cl content significantly decreased to 1–2% after flushing, similar to that of Cl content in the standard, non-salted food waste char. On the other hand, a significant amount of Na was found in pyrolyzed char even after flushing resulting from a phenomenon in which salt is dissolved in water while flushing and Na ions are adsorbed. FT-IR analysis showed that salt in waste affects the binding of aromatic carbons to compounds in the pyrolysis process. The NMR spectroscopy demonstrated that the aromatic carbon content, which indicates the stability of biochar, is not influenced by the salt content and increases with increasing pyrolysis temperature.
Mostrar más [+] Menos [-]Fresh produce and their soils accumulate cyanotoxins from irrigation water: Implications for public health and food security Texto completo
2017
Lee, Seungjun | Jiang, Xuewen | Manubolu, Manjunath | Riedl, Ken | Ludsin, Stuart A. | Martin, Jay F. | Lee, JiYoung
Microcystin (MC), a hepatotoxin that can adversely affect human health, has become more prevalent in freshwater ecosystems worldwide, owing to an increase in toxic cyanobacteria blooms. While consumption of water and fish are well-documented exposure pathways of MCs to humans, less is known about the potential transfer to humans through consumption of vegetables that have been irrigated with MC-contaminated water. Likewise, the impact of MC on the performance of food crops is understudied. To help fill these information gaps, we conducted a controlled laboratory experiment in which we exposed lettuce, carrots, and green beans to environmentally relevant concentrations of MC-LR (0, 1, 5, and 10μg/L) via two irrigation methods (drip and spray). We used ELISA and LC-MS/MS to quantify MC-LR concentrations and in different parts of the plant (edible vs. inedible fractions), measured plant performance (e.g., size, mass, edible leaves, color), and calculated human exposure risk based on accumulation patterns. MC-LR accumulation was positively dose-dependent, with it being greater in the plants (2.2–209.2μg/kg) than in soil (0–19.4μg/kg). MC-LR accumulation varied among vegetable types, between plant parts, and between irrigation methods. MC-LR accumulation led to reduced crop growth and quality, with MC-LR persisting in the soil after harvest. Observed toxin accumulation patterns in edible fractions of plants also led to estimates of daily MC-LR intake that exceeded both the chronic reference dose (0.003μg/kg of body weight) and total daily intake guidelines (0.04μg/kg of body weight). Because the use of MC-contaminated water is common in many parts of the world, our collective findings highlight the need for guidelines concerning the use of MC-contaminated water in irrigation, as well as consumption of these crops.
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