Water vapour sorption isotherms describe the relationship between water content and water activity. Depending on the nature of food powder (crystalline or amorphous), the shape of isotherm is different. Mostly food powders have complex structures, including potentially crystallisable solutes such as sugars, which show changes in crystallinity during the adsorption of water. Even for such an apparently simple system as crystalline sugar, numerous factors affect the adsorption of water vapour and, as a consequence, the storage stability. The presence of a thin film of saturated solution at the surface of the crystal, grain size distribution and the inclusion of mother liquor droplets in the crystal are some of the factors which perturb the equilibrium relative humidity of sugar and its aptitude to caking. These conditions were carefully studied at the level of the laboratory and in a pilot silo. Conditions of "decaking" (recovering a flowing sugar after caking) were also established. In the case of noncrystalline powders, water activity, together with glass transition temperature, is important to determine if it is necessary to interpret the origin of the formation of bridges between food powder particles and the caking phenomenon.

The emerging popularity of the nexus discussion reflects the ongoing transition from a sectoral or silo approach to an integrative approach to address the global challenges pertinent to the three essential resources: food, energy, and water (FEW). Cities are critically important for advancing regional sustainable development and are thus placed at the center of the FEW nexus. This paper provides a comprehensive literature review to debate the current concepts and methods of the FEW nexus at different scales, with the aim of developing a conceptual knowledgebase framework for scientific analysis and policy making associated with the urban FEW nexus. Although the concept of nexus thinking has been widely accepted, a consistent and explicit cognition of the FEW nexus is still lacking, and a sophisticated methodological modeling framework is urgently required at various scales. As such, we proposed a three-dimensional conceptual framework of the urban FEW nexus from the perspective of resource interdependency, resource provision and system integration. This framework is useful in steering the systematic modeling and integrative management of the complex nexus issues of urban systems with different perspectives. Finally, the future directions of urban nexus research are identified from four aspects, including systematic characterization, cross-region tele-connection mechanisms, co-decision model development, and governance transition.

Managers of federal, state, local, and nonprofit organizations around the world are faced with the complex task of managing interconnected systems of scarce resources. One key example of this has been the recent research on the connections between water, energy, and food/agriculture, and the problem of managing these resources to be sustainable and reduce the likelihood of resource depletion. While engineering research has focused on achieving greater efficiencies in resource management, less attention has been given to issues of governance within the fragmented, decentralized, and polycentric systems that are responsible for resource delivery. The central question animating this paper is whether resource management decisions in water, energy, and food are siloed, and what theoretical frameworks can be leveraged to develop strategies to break down existing silos. Results from a survey of water agencies suggests that there is little communication between the water, energy, and food policy areas. If achieving greater nexus requires increased communication and repeated interactions, there is significant work to be done to re-think how policy and management are organized and conducted.

The existence of a water-energy-food ‘nexus’ has been gaining significant attention in international natural resource policy debates in recent years. We argue the term ‘nexus’ can be currently seen as a buzzword: a term whose power derives from a combination of ambiguous meaning and strong normative resonance. We explore the ways in which the nexus terminology is emerging and being mobilised by different stakeholders in natural resource debates in the UK context. We suggest that in the UK the mobilisation of the nexus terminology can best be understood as symptomatic of broader global science-policy trends, including an increasing emphasis on integration as an ideal; an emphasis on technical solutions to environmental problems; achievement of efficiency gains and ‘win-wins’; and a preference for technocratic forms of environmental managerialism. We identify and critique an ‘integrative imaginary’ underpinning much of the UK discourse around the concept of the nexus, and argue that attending to questions of power is a crucial but often underplayed aspect of proposed integration. We argue that while current efforts to institutionalise the language of the nexus as a conceptual framework for research in the UK may provide a welcome opportunity for new forms of transdisciplinary, they may risk turning nexus into a ‘matter of fact’ where it should remain a ‘matter of concern’. In this vein, we indicate the importance of critique to the development of nexus research.

Green and blue infrastructure (GBI) is an innovative strategy to tackle food-water-energy (FWE) nexus issues. GBI can provide the benefits of food production, energy saving and generation, waterlogging control, rainwater cleansing and harvesting. Significant efforts have been devoted to measuring the implications of GBI on FWE nexus. However, there is little research to simulate the multiple linkages between GBI and FWE nexus in urban areas, and the lack of a unified methodology framework also easily leads to an understanding bias of their connections and makes it challenging to compare the results. Focusing on the prior published literature, this study clarifies the interactions between GBI and FWE nexus and reviews the methods to quantify the implications of GBI on FWE nexus in cities, including FWE-related benefits, life cycle environmental impacts, and avoided upstream environmental footprints induced by FWE-related benefits. It is revealed that most studies focus on the FWE-related benefits or (and) life cycle environmental impacts of GBI from a silo perspective. Researchers pay little attention to the avoided trans-boundary environmental footprints by GBI, and carbon footprint is the greatest concern in the existing research. There is little evidence on comprehensive quantifications regarding multiple impacts of GBI on FWE nexus at the urban scale. The review outlines methods to simulate the linkages between GBI and FWE nexus and calls for a holistic methodological framework to apply at the urban scale. Such assessment practices would make sense for FWE-oriented resilience planning and governance for urban GBI implementation.

The inhibitory effect of butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) mixture on fungal populations, Aspergillus section Flavi and aflatoxins accumulation in in-pod peanuts during storage in big bags was investigated. In-pod peanuts were previously conditioned at different water activities (0.94, 0.88, 0.84 and 0.76 aw) and treated with food-grade antioxidants. Both control and treated peanuts were stored for 6 months and sampled at monthly intervals. BHA-BHT mixture reduced the incidence of peanut fungal populations between 0.6-20.4% and between 1.2-33.1% during 1-3 and 4-5 storage months, respectively. Aspergillus section Flavi counts decreased with 36.5%, 46.3% and 77.4% in peanuts conditioned at 0.94, 0.84 and 0.76 aw levels and treated with antioxidants. At the above peanut aw conditions, the treatment applied reduced aflatoxin accumulation by 72.1%, while any effect on this metabolite production was observed at 0.88 aw. The antioxidant formulation used in this study has the potential to control aflatoxigenic populations in in-pod peanuts stored in half-permeable silos at ≤0.84 aw level.

Water, energy, food, land and climate form a tightly-connected nexus in which actions on one sector impact other sectors, creating feedbacks and unanticipated consequences. This is especially because at present, much scientific research and many policies are constrained to single discipline/sector silos that are often not interacting (e.g., water-related research/policy). However, experimenting with the interaction and determining how a change in one sector could impact another may require unreasonable time frames, be very difficult in practice and may be potentially dangerous, triggering any one of a number of unanticipated side-effects. Current modelling often neglects knowledge from practice. Therefore, a safe environment is required to test the potential cross-sectoral implications of policy decisions in one sector on other sectors. Serious games offer such an environment by creating realistic ‘simulations’, where long-term impacts of policies may be tested and rated. This paper describes how the ongoing (2016–2020) Horizon2020 project SIM4NEXUS will develop serious games investigating potential plausible cross-nexus implications and synergies due to policy interventions for 12 multi-scale case studies ranging from regional to global. What sets these games apart is that stakeholders and partners are involved in all aspects of the modelling definition and process, from case study conceptualisation, quantitative model development including the implementation and validation of each serious game. Learning from playing a serious game is justified by adopting a proof-of-concept for a specific regional case study in Sardinia (Italy). The value of multi-stakeholder involvement is demonstrated, and critical lessons learned for serious game development in general are presented.

Sustainable agricultural intensification requires irrigation methods and strategies to minimize yield penalties while optimizing water, land and energy use efficiencies. We assessed, from a silo-based and integrated water-energy-food (WEF) nexus perspective, the performance of irrigation technologies in different agro-climatic regions. Secondary to this, we assessed the impact of adopting systematic approaches such as the WEF nexus on improving efficiency in irrigated agriculture through irrigation modernization. The evidence-based perspectives of silo-based performances individually considered the metrics of yield (Y), water use efficiency (WUE), and energy productivity (EP). The WEF nexus approach applied sustainability polygons to integrate the three metrics into a nexus index representing the holistic performance of the irrigation technologies. Silo-based performance in temperate regions suggests net gains for WUE (+1.10 kg m-3 ) and Y (+6.29 ton ha-1 ) when transitioning from furrow to sprinkler irrigation, with a net loss in EP (-3.82 ton MJ-1 ). There is potential for a net loss on EP (-3.33 ton MJ-1 ) when transitioning from furrow to drip system in temperate regions. The best performance of irrigation technologies in dry regions in water, energy and food silos was achieved by sprinkler, drip and furrow irrigation systems, respectively. Thus, appraising irrigation technologies from a silos perspective promotes individual silos, which renders an unsustainable picture of the performance of irrigation systems. The integrative WEF nexus approach successfully highlighted the trade-offs and synergies in the nexus of water, energy and food in irrigated agriculture. Drip irrigation led all irrigation technologies in WEF nexus performance in dry (21.44 unit2 ), tropical (23.98 unit2 ), and temperate regions (47.28 unit2 ). Overall, the irrigation modernization pathway to drip technology from either furrow or sprinkler systems improves irrigated agriculture’s WEF nexus performance in all three regions for more crop per drop per joule per hectare under climate change. This can promote inclusive and sustainable irrigation development within the planetary boundaries.

The Food-Energy-Water (FEW) nexus for urban sustainability needs to be analyzed via an integrative rather than a sectoral or silo approach, reflecting the ongoing transition from separate infrastructure systems to an integrated social-ecological-infrastructure system. As technology hubs can provide food, energy, water resources via decentralized and/or centralized facilities, there is an acute need to optimize FEW infrastructures by considering cost-benefit-risk tradeoffs with respect to multiple sustainability indicators. This paper identifies, categorizes, and analyzes global trends with respect to contemporary FEW technology metrics that highlights the possible optimal integration of a broad spectrum of technology hubs for possible cost-benefit-risk tradeoffs. The challenges related to multiscale and multiagent modeling processes for the simulation of urban FEW systems were discussed with respect to the aspects of scaling-up, optimization process, and risk assessment. Our review reveals that this field is growing at a rapid pace and the previous selection of analytical methodologies, nexus criteria, and sustainability indicators largely depended on individual FEW nexus conditions disparately, and full-scale cost-benefit-risk tradeoffs were very rare. Therefore, the potential full-scale technology integration in three ongoing cases of urban FEW systems in Miami (the United States), Marseille (France), and Amsterdam (the Netherlands) were demonstrated in due purpose finally.