111 research outputs found

    Aquatic food security:insights into challenges and solutions from an analysis of interactions between fisheries, aquaculture, food safety, human health, fish and human welfare, economy and environment

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    Fisheries and aquaculture production, imports, exports and equitability of distribution determine the supply of aquatic food to people. Aquatic food security is achieved when a food supply is sufficient, safe, sustainable, shockproof and sound: sufficient, to meet needs and preferences of people; safe, to provide nutritional benefit while posing minimal health risks; sustainable, to provide food now and for future generations; shock-proof, to provide resilience to shocks in production systems and supply chains; and sound, to meet legal and ethical standards for welfare of animals, people and environment. Here, we present an integrated assessment of these elements of the aquatic food system in the United Kingdom, a system linked to dynamic global networks of producers, processors and markets. Our assessment addresses sufficiency of supply from aquaculture, fisheries and trade; safety of supply given biological, chemical and radiation hazards; social, economic and environmental sustainability of production systems and supply chains; system resilience to social, economic and environmental shocks; welfare of fish, people and environment; and the authenticity of food. Conventionally, these aspects of the food system are not assessed collectively, so information supporting our assessment is widely dispersed. Our assessment reveals trade-offs and challenges in the food system that are easily overlooked in sectoral analyses of fisheries, aquaculture, health, medicine, human and fish welfare, safety and environment. We highlight potential benefits of an integrated, systematic and ongoing process to assess security of the aquatic food system and to predict impacts of social, economic and environmental change on food supply and demand

    Closed-form equations for flange force and maximum deflection of box-beams of fiber reinforced polymer with partial shear interaction between webs and flanges

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    Presented in the paper is the formulation of a governing second-order differential equation for the moment distribution along the length of a beam having two interfaces with partial shear interaction where two flange and two web components join to form the box shaped section. For practical applications such a closed-section beam of Fiber Reinforced Polymer (FRP) can be assembled from individual pultruded profiles using mechanical fasteners. This assembly approach can be used to construct deeper section sizes than can be achieved with a single pultrusion, and which can be transported in flat-pack units. In developing the governing equation for flexural response account is made of the finite connection stiffness at the web/flange interfaces by applying conventional elastic beam theory. The differential equation for the partial interaction problem is solved to formulate closed form equations for the flange force and the maximum deflection of a simply supported beam under four-point bending. A numerical parametric study is presented to show changes in beam performance indicators with the degree of shear interaction between the upper and lower bounds of full- and non-interaction. Results from a series of load tests using a three-layered prototype FRP beam are shown to be in good agreement. The theoretical predictions for maximum deflection are however found to be directly linked to the appropriateness of the measured connection stiffness entered into the closed-form equation

    Determination of Wax Concentration in Sunflower-seed Oil

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    Isothermal crystallization of waxes was studied by using an optical setup. The induction time of crystallization was assessed as a function of wax concentration. The relationship was found to be a decreasing exponential curve. The wax content of some of the solutions prepared in the laboratory was determined by calculating the crystallization induction time. The values obtained were compared to those from different methods (cold test, microscopic, and turbidimetric methods). The results obtained with the optical setup method are similar to those obtained with other methods for concentrations greater than 100 ppm. An analysis of variance test was used to verify the authenticity of the values obtained with the optical method. Results showed that the method used to determine wax concentration, the concentration of the sample, and the relationship between both parameters do not affect significantly the values of percentage relative errors (P\u3c0.05) obtained for concentrations greater than 100 ppm. Values obtained for wax content within the range 0–100 ppm could not be compared since the microscopic and turbidimetric methods are not sensitive enough, unlike the optical setup, to detect wax amounts in such low concentration

    Development of oil-in-water emulsions based on rice bran oil and soybean meal as the basis of food products able to be included in ketogenic diets

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    The aim of this work was to develop rice bran oil-in-water emulsions stabilized with proteins and polysaccharides from soybean meal as the basis of food products able to be included in ketogenic diet. The effect of the formulation (ketogenic ratios and oil mass fractions) and the high-pressure homogenization conditions (number of homogenization cycles) on the properties of the resulting O/W emulsions was evaluated. All freshly prepared emulsions showed multimodal particle size distributions and shear-thinning behaviour. At a fixed ketogenic ratio, all emulsions had the same oil to emulsifiers + stabilizers proportion, but increasing their oil mass fraction resulted in systems composed by smaller particles with greater interfacial area, and apparent viscosity. The same effect was observed by increasing the number of homogenization cycles. Meanwhile, increasing the ketogenic ratio (at a fixed oil mass fraction) diminished its apparent viscosity. Most of the studied emulsions were stable for seven days of quiescent refrigerated storage, although some changes in its particle size distributions were observed. Only, the stored emulsions with the highest ketogenic ratio and the lowest oil mass fraction presented gravitational separation but no phase separation. Emulsions prepared after five homogenization cycles presented greater stability to the coalescence than those prepared in one cycle
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