Dispersions of commercial casein and whey protein and laboratory-prepared soybean protein were studied in mixed dispersants of water with various aliphatic alcohols, methanol, ethanol, n-propanol and 2-propanol. Supernatant and protein sediments were separated by centrifugation in two steps: 1800 rpm 10 min, followed by centrifugation of the supernatant at 50000 rpm for 60 min (125000xg). A gel-like protein sediment obtained at low alcohol concentration by high-g centrifugation increased in amounts as a function of the alcohol concentration until it progressively transformed, with higher alcohol concentrations, into an opaque flock (precipitate), sedimenting at 1800 rpm. It was concluded that the sediment obtained by ultracentrifugation was a protein of increased density which was produced by partial and progressive dehydration and alcohol binding. The conversion of the sediment into a flock or precipitate is discussed in terms of the hydrophilic-lipophilic balance of the protein and of the polar-nonpolar character of the dispersant.

The Food-Energy-Water-Waste Nexus (FEWWN) represents the interconnections between food, energy, water, and waste production systems, and it has become a key research area. Enormous quantities of agricultural and organic wastes are produced throughout the FEWWN. Often, these wastes are not treated appropriately because their true costs are rarely quantified, and usually externalized to the environment. This shortcoming is addressed from a systems perspective fused with approaches from ecological economics. A regional bioenergy production model where bioenergy may be produced from ethanol and/or agricultural wastes is constructed. Ecosystem service valuation methods are integrated into the framework, allowing for bioenergy production systems to be designed to minimize ecological damage and/or maximize ecological restoration. These values are captured within a Green Gross Domestic Product (Green GDP) objective that values both energy produced and ecosystem service values lost/gained. System profit is another objective in the multi-objective model. The framework is applied to a bioenergy production system for the U.S. state of New York, which aims to produce 10% more bioenergy compared to its current levels. Net changes in Green GDP ranged from -$16.5 M/y to $90.6 M/y, and corresponding profits ranged from $7.2 M/y to -$74.5 M/y. Corn grain ethanol was the dominant source of bioenergy in solutions with higher profits, while ethanol from corn stover and bioelectricity generated from animal manure biogas contributed more bioenergy in solutions with increasing Green GDP. Results show that there is a trade-off between promoting natural capital/ecological health and financial profit. FEWWN system design should consider these trade-offs moving forward.

Socioeconomic and climatic changes and limited water resources pose various challenges to water, energy, and food sectors across the globe. The inevitable interactions between water, energy, and food systems bring about trade-offs but also synergies under different decisions and policies. To gain insights into these issues, we developed a water-energy-food (WEF) nexus model that incorporates both production (supply) and demands sides of WEF systems into a single system-of-systems model using the system dynamics (SD) approach. The model is applied to Saskatchewan, Canada, and so is named WEF-Sask. The model results reveal the various levels of sensitivities of water, energy, and food (and feed) sectors to the socioeconomic and climatic drivers. The analysis of trade-offs and synergies shows that the proposed large irrigation expansion (400%) boosts food production by 1.6% while reducing hydropower production by 2.7% in Saskatchewan. Wind energy expansion strategy (from 5% to 30% of total capacity) makes synergies that not only contribute to electricity supply but also reduce greenhouse gas emissions, industrial water demand, and groundwater use by 2.0, 5.7, and 3.8%, respectively. Biofuel use (blending mandate: 10% ethanol and 5% biodiesel) in transportation cuts GHG emissions by 1.2% but reduces the potential food export (food surplus) by 5.0%. The WEF-Sask model allows for scenario analysis toward integrated resources management, and its generic model structure can be expanded to other regions.

To find a sustainable way of supplying food, energy, and water (FEW) while simultaneously protecting the ecosystem services, it is imperative to build greater understanding on interconnections, feedback, and dependencies in FEW systems. The FEW nexus has developed as a field of study to provide frameworks for such pursuits. Building upon previous work in this paper, we analyze FEW resources through the development of a virtual water trade network using the US network of food and energy flows and their associated virtual water contents. Our main objective is to provide a quantitative estimation of the virtual water embodied in the internal US food and energy transfers and analyze the associated interdependencies of these connections. Three methodological advancements demonstrate the novelty of this work. First, unlike existing FEW virtual water modeling studies, our work separates corn into both food and energy resources accounting for the significant use of corn for ethanol in the United States. Second, we apply recently published water consumption values for energy commodities confirming the variation between previous water footprint studies and these more accurate accounting procedures. Third, we examine network properties of the trade flows furthering FEW nexus literature and showcasing avenues for future research. Our results indicate that accounting for the transfer of corn from the food commodity network to the energy commodity network leads to a virtual water footprint decline of 11% for the cereal grain virtual water network. Additionally, the food trade network shows highly dense and connected properties compared to the energy trade network. Finally, our results indicate that transfers of water footprints between water scarce and water abundant states differ substantially between food and energy virtual water networks. A quantifiable understanding of the water footprint network embodied in the food and energy trade can help in developing policies for promoting conservation and efficiency in the context of the FEW nexus.

A green, switchable water dispersive liquid–liquid microextraction (SWDLL-ME) method is introduced for the first time as a preconcentration/separation tool for measuring trace levels of cadmium (Cd) in real water and food samples. In the present study, a switchable aqueous solution of polar organic solvent (acetonitrile) was reversibly switched (on and off) from miscible monophasic to immiscible biphasic in aqueous medium by exposure to an anti-solvent trigger (CO₂). The developed SWDLL-ME was successfully applied as an extraction method for the extraction of a Cd–PAN complex (1-(2-pyridylazo)-2-naphthol) in polar organic solvent (PS). The solvent enriched phase containing Cd–PAN was separated from the switchable water (SW) and treated with 200 μL of 0.1 mol L⁻¹ HNO₃ with ethanol (1 : 1, v/v) in order to reduce its viscosity, and it was then easily injected into a GFAAS for analysis. The SW was reused for the next assay after the removal of CO₂. The switching phenomenon of the SW from low to high polarity was confirmed by FTIR spectroscopy and conductivity measurements. The enrichment factor and limit of detection of the proposed method were 22 and 0.38 ng L⁻¹, respectively. Validation of the developed method was carried out by analyzing certified reference materials (SLRS-4 Riverine water and NIST SRM 1515 Apple leaves).

The thermal reaction between cysteine and furfural was investigated at 65 degrees C in five-component food grade oil/water (O/W) microemulsions of R-(+)-limonene/ethanol, EtOH/water/propylene glycol, PG/Tween 60 as apart of a systematic study on the generation of aroma compounds by utilizing structured W/O and O/W fluids. The furfural-cysteine reaction led to the formation of unique aroma compounds such as 2-furfurylthiol (FFT), 2-(2-furanyl)thiazolidine (main reaction product), 2-(2-furanyl)-thiazoline, and N-(2-mercaptovinyl)-2-(2-furanyl)thiazolidine. These products were determined and characterized by GC-MS. Enhancement in flavor formation is termed "microemulsion catalysis". The chemical reaction occurs preferably at the interfacial film, and therefore a pseudophase model was assumed to explain the enhanced flavor formation. The product internal composition is dictated by process conditions such as temperature, time, pH, and mainly the nature of the interface. Increasing water/PG ratio leads to a dramatic increase in the initial reaction rate (V0). V0 increased linearly as a function of the aqueous phase content, which could be due to the increase in the interfacial concentration of furfural. Microemulsions offer a new reaction medium to produce selective aroma compounds and to optimize their formation.

The separation and determination of the ten water-soluble vitamins by using capillary electrophoresis in the micellar electrokinetic chromatography in a single run are proposed. The method uses low toxicity and cost solvent (ethanol) as modifier of background electrolyte (BGE) attending to the Green Chemistry principles. The electrophoretic method uses 10.0 % (v/v) ethanol, 2.0 % (w/v) SDS, 0.02 mol L⁻¹borate at pH 8.70 as BGE. The standard and real sample solutions were injected in the eletrophoretic system by hydrodynamic injection under pressure of 0.80 psi for 8 s, and the separation was carried out in a fused silica capillary under a potential of 28 kV at 25 °C; the analytical signals were monitored at 214 nm. The analytical method is precise (r.s.d. < 6 %), accurate (better than 9 %), selective, sensitive, robust, simple, and presents high analytical frequency as ten water-soluble vitamins were separated in only 18 min, with migration times of 5.75 ± 0.02, 6.81 ± 0.02, 8.13 ± 0.04, 8.80 ± 0.07, 8.98 ± 0.06, 11.10 ± 0.08, 11.34 ± 0.05, 13.85 ± 0.15, 14.82 ± 0.04, and 17.85 ± 0.30 min. Detection and quantification limits of 0.34, 0.32, 0.27, 0.20, 2.50, 4.98, 4.92, 0.30, 0.86 and 0.28 mg L⁻¹and 1.02, 0.97, 0.83, 0.62, 7.56, 15.09, 14.91, 0.90, 2.59 and 0.83 mg L⁻¹, for vitamins PP (nicotinamide), B₁₂(cyanocobalamin), B₂(riboflavin), B₆(pyridoxine), B₈(biotin), C (ascorbic acid), B₅(pantothenic acid), B₃(nicotinic acid), B₁(thiamine), and B₉(folic acid), respectively. Excellent recoveries (intra and inter-day) were obtained and, when the method was applied to food supplement analyses the results were in agreement with the conventional HPLC methods.

Biofuels in Ecuador were born with the purpose of achieving an effective substitution of imports of petroleum derivatives. The objective of this research is to analyze the impact that biofuel production has on water, food, and energy, and its contribution to reducing the growing dependence on fossil fuels in the transportation sector in Ecuador. The analysis focuses on ethanol produced from sugar cane, which is used to produce Ecopaís gasoline. The methodology is composed of three parts. For the first part, Geographic Information Systems were used; for the second, the FAO Penman-Monteith method; and, finally, in the third, the energy consumption was obtained through secondary information. As a result, taking the year 2019 as a reference, ethanol became the ninth product with the largest amount of land suitable for agriculture, and the seventh with the most irrigated areas in a country that suffers from malnutrition. Countries with a tropical climate and highly dependent on imports of petroleum derivatives are tempted to implement policies to promote biofuels. However, due to the risks that this renewable fuel represents on food security, other options for reducing its energy dependence should be exhausted.

As bio-ethanol is developing rapidly, its impacts on food security, water security and the environment begin to receive worldwide attention, especially within the Water–Energy–Food nexus framework. The aim of this study is to present an integrated method of assessing sweet sorghum-based ethanol potential in China in compliance with the Water–Energy–Food nexus principles. Life cycle assessment is coupled with the DSSAT (the Decision Support System for Agrotechnology Transfer) model and geographic information technology to evaluate the spatial distribution of water consumption, net energy gain and Greenhouse Gas emission reduction potentials of developing sweet sorghum-based ethanol on marginal lands instead of cultivated land in China. Marginal lands with high water stress are excluded from the results considering their unsuitability of developing sweet sorghum-based ethanol due to possible energy–water conflicts. The results show that the water consumption, net energy gain and Greenhouse Gas emission reduction of developing sweet sorghum-based ethanol in China are evaluated as 348.95 billion m3, 182.62 billion MJ, and 2.47 million t carbon per year, respectively. Some regions such as Yunnan Province in south China should be given priority for sweet sorghum-based ethanol development, while Jilin Province and Heilongjiang Province need further studies and assessment.