The purpose of this paper is to analyze the effect of environmental innovation on the balance of the food, energy, and water (FEW) nexus in the food service industry. The study was carried out through the completion of questionnaires by managers of food service companies in Brazil. Structural equation modeling (SmartPLS) was used for the analysis, which was based on 206 responses. The results show that food waste can be reduced by innovation in the planning of menus and purchases and in the process of food preparation. Furthermore, the reduction of natural resource consumption, especially of water and energy, can be achieved by leveraging changes in internal processes. In this sense, the typical trade-offs associated with the FEW nexus can be solved through environmental innovation. In addition, collaborative approaches between farms, suppliers and governments are essential for the implementation of the innovation processes. The paper presents suggestions for scholars, policy makers and managers in the food service industry to address the FEW nexus challenges.

Water activity has historically been and continues to be recognised as a key concept in the area of food science. Despite its ubiquitous utilisation, it still appears as though there is confusion concerning its molecular basis, even within simple, single component solutions. Here, by close examination of the well-known Norrish equation and subsequent application of a rigorous statistical theory, we are able to shed light on such an origin. Our findings highlight the importance of solute-solute interactions thus questioning traditional, empirically based “free water” and “water structure” hypotheses. Conversely, they support the theory of “solute hydration and clustering” which advocates the interplay of solute-solute and solute-water interactions but crucially, they do so in a manner which is free of any estimations and approximations.

In this study, 13 types of organic materials were oxidized using H₂O₂in a continuous flow reactor under the condition of supercritical water. The effect of the operational parameters on the conversion of total organic carbon (TOC) and total nitrogen (TN) was investigated, and the resulting quality of treated water was analyzed. It was found that these materials were easily oxidized with a TOC conversion achieving 99 % at temperature of 460 °C and TN conversion reaching 94 % at temperature of 500 °C. Rice decomposition was rapid, with TOC and TN decomposition rates of 99 % obtained within residence of 100 s at temperature of 460 °C. At temperature of 460 °C, pressure of 24 MPa, residence time of 100 s, and excess oxygen of 100 %, the quality of treated water attained levels commensurate with China’s Standards for Drinking Water Quality. Reaction rate equation parameters were obtained by fitting the experimental data to the differential equation obtained using the Runge–Kutta algorithm. The decrease of the TOC in water samples exhibited reaction orders of 0.95 for the TOC concentration and 0.628 for the oxygen concentration. The activation energy was 83.018 kJ/mol.

Water content quantification of raw polysaccharide materials for food processing is generally performed by gravimetric analysis or titrimetric methods, which are time- and energy-consuming, non-eco-friendly and sample destructive. The present study develops and validates a new approach, based on the use of Fourier transform infrared (FTIR) spectroscopy, resulting in a model of the water content of carboxymethyl cellulose (CMC) polysaccharides. Samples of CMC were exposed to different relative humidity conditions. Water content was determined by standard gravimetric methods (OIV-Oeno 404–2010) and compared with the area of FTIR absorption in the range 3675–2980 cm⁻¹, attributed to the stretching of OH groups. The strong correlation between gravimetric results and FTIR area (R² = 0.88) showed no signs of bias across the water content range. A cross-validation technique to predict the water content by band area was assessed obtaining a general equation: y = 2.12 x + 2.80 with a high repetitively and good prediction of the tested models.

Water affects safety, stability, quality and physical properties of food. The influence of water on physical properties of food is dependent on the state of water in food. The state, expressed as water activity, is briefly discussed in the paper. Further, the influence of water on such physical properties as rheological, thermal, mass transfer, electrical, optical and acoustic is presented in details.

Water-adsorption data and glass transition temperatures (Tg) of maltodextrins with dextrose equivalent (DE) values ranging from 4 to 38, horseradish roots, and strawberries were used to establish relationships between water activity (aw), water content (m), and Tg. Critical m values were considered as those depressing Tg to 25C. Corresponding values of critical aw were obtained from GAB isotherms that were used to model water adsorption. The use of BET isotherms was tested, but the model showed poor correlation with experimental data at high aw values, especially for low DE maltodextrins. Critical m and aw values were lowest for strawberries (1.5 g H2O/g solids; 0.07 aw). The values increased with decreasing DE, ranging from 72 (0.44 aw) to 11.2 g H2O/g solids (0.70 aw). Understanding of water-sorption properties and Tg is valuable in controlling processability and stability, and for determining of food-packaging requirements.

The present investigation deals with analyzing the validity of GAB model for isotherms of different food products. The model was found satisfactory for different food products with different shapes of of isotherms under widely varying conditions (temperature: 4-140 C; moisture %D.B.:2-71; activity: 0.059-0.99). The present study covered a wide range of food products from green vegetables, fruits, cereals and nuts to casein, pectin and protein. Food products with complex molecular structure and high sugar contents were also included. A non linear regression method was applied to evaluate the six parameters of the GAB model. The Guggenheim constant, factor for multilayer molecules and the monolayer moisture were assumed to follow an Arrhenius type relationship with temperature variation. The values of net isosteric heat of sorption obtained by GAB model and Clausius Clapeyron equation were compatible. Monolayer moisture values for food products obtained by GAB model were in agreement with values reported in the literature.

When a starchy food such as a rice grain or a strand of noodle is boiled, a high moisture region is generated at the surface spreading inward, producing a low moisture core. The characteristic features of the change of moisture profile were recently observed by nuclear magnetic resonance imaging (MRI). However, the profile cannot be described by any existing mathematical model based on the principle that water molecules are driven by the gradient of moisture content. In this paper, a new mathematical model is proposed using a new concept, water demand (WD). In this model, migration of water is driven by the gradient of WD, which is defined as the difference between the ceiling moisture content and the existing moisture content. This model is demonstrated to have a potential to describe the characteristic features of the change of moisture profile in starchy food during boiling.

Continued rise in global human population, per capita consumption, urbanization and migration towards coastal cities present challenges in fulfilling the energy, water and food demands of coastal communities in sustainable manner. In this regard, as a solution to the problem, a new multigeneration system is proposed to address some of the most common and vital needs of such communities. The system developed is based on principles of sustainability and decentralisation and is driven by renewable energy sources including sun and biomass. It provides electricity, fresh water, hot water for domestic use, HVAC for space air-conditioning and food storage, in addition to hot air for food drying. In the proposed hybrid system, biomass energy is integrated with solar energy in a complimentary manner as a means to maximise outputs and enhance system resilience against weather conditions and day/night cycles. Designing for resilience enables a type of operation that fulfils parallel demands in a continuous stable and flexible operation which can be optimised depending on the requirements. The main sub-systems used in the proposed multigeneration system consist of a Biomass combustor, Concentrated Solar Power (CSP), a Rankine Cycle, a desalination unit and an Absorption Cooling System (ACS). A comprehensive integrated thermodynamic model of the entire system is developed by application of energy, mass, entropy and exergy balance equations. Moreover, effects of various inputs and environmental variables on the outputs and performance has also been studied. Results reveal that the proposed system is capable of fulfilling some of the coastal community’s essential requirements in an efficient and ecologically benign manner. The energy and exergy efficiencies of the proposed system are 55% and 18%, respectively. The outputs of the system include 1687 m³/day of produced fresh water, ~4 MW of cooling, ~13 MW of electricity, ~73 kg/s of hot air for food drying, and ~41 kg/s of hot water for domestic use. Furthermore, the highest amount of exergy destruction is observed in biomass combustion unit and the solar PTCs.

A novel method was used to estimate assimilation efficiencies (AEs) of dissolved and food associated PCBs (IUPAC 31, 49, and 153) by the Baltic Sea blue mussel (Mytilus edulis). Mussels were exposed to radiolabeled PCBs in a series of short-term toxicokinetic experiments at different algal food concentrations, both at apparent steady-state (ASS) and non-steady-state (NSS) conditions in respect to PCB partitioning between water and algae. The PCB AEs were calculated using a physiologically based bioaccumulation model where experimentally determined uptake and exposure rates at ASS and NSS conditions were combined into linear equation systems, which were solved for PCB AE from water and food. A positive relationship between PCB uptake and algae clearance by the mussels was observed for all three PCBs. The PCB AEs from both water and food increased with congener hydrophobicity (octanol/water partition coefficient [K(ow)]), but AEs decreased with increases in water pumping and filtration rate of the mussels, respectively, The average contribution of food-associated PCB to the total uptake also increased with K(ow) from approximately 30% for PCB 31 and PCB 49 to 50% for PCB 153, mainly as a consequence of increased sorption to the algal food.